A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Acid rain is rain or any other form of precipitation that is unusually acidic, i.e. elevated levels of hydrogen ions (low pH). It has harmful effects on plants, aquatic animals, and infrastructure. Acid rain is mostly caused by emissions of compounds of sulfur, nitrogen, and carbon, which react with the water molecules in the atmosphere to produce acids. However, it can also be caused naturally by the splitting of nitrogen compounds by the energy produced by lightning strikes, or the release of sulfur dioxide into the atmosphere by phenomena of volcano eruptions.

Source: Wikipedia

See eolic turbine.

Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or damages the natural environment, into the atmosphere.

The atmosphere is a complex, dynamic natural gaseous system that is essential to support life on planet Earth. Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the Earth's ecosystems.

An air pollutant is known as a substance in the air that can cause harm to humans and the environment. Pollutants can be in the form of solid particles, liquid droplets, or gases. In addition, they may be natural or man-made.

Pollutants can be classified as either primary or secondary. Usually, primary pollutants are substances directly emitted from a process, such as ash from a volcanic eruption, the carbon monoxide gas from a motor vehicle exhaust or sulfur dioxide released from factories.

Secondary pollutants are not emitted directly. Rather, they form in the air when primary pollutants react or interact. An important example of a secondary pollutant is ground level ozone — one of the many secondary pollutants that make up photochemical smog.

Note that some pollutants may be both primary and secondary: that is, they are both emitted directly and formed from other primary pollutants.

About 4 percent of deaths in the United States can be attributed to air pollution, according to the Environmental Science Engineering Program at the Harvard School of Public Health.

Major primary pollutants produced by human activity include:

•    Sulfur oxides (SOx) - especially sulfur dioxide, a chemical compound with the formula SO2. SO2 is produced by volcanoes and in various industrial processes. Since coal and petroleum often contain sulfur compounds, their combustion generates sulfur dioxide. Further oxidation of SO2, usually in the presence of a catalyst such as NO2, forms H2SO4, and thus acid rain. This is one of the causes for concern over the environmental impact of the use of these fuels as power sources.
•    Nitrogen oxides (NOx) - especially nitrogen dioxide are emitted from high temperature combustion. Nitrogen dioxide is the chemical compound with the formula NO2. It is one of the several nitrogen oxides. This reddish-brown toxic gas has a characteristic sharp, biting odor. NO2 is one of the most prominent air pollutants.
•    Carbon monoxide - is a colorless, odorless, non-irritating but very poisonous gas. It is a product of the incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide.
•    Carbon dioxide (CO2) - a greenhouse gas emitted from combustion, it is also a gas vital to living organisms. It is a natural gas in the atmosphere.
•    Volatile organic compounds - VOCs are an important outdoor air pollutant. In this field they are often divided into the separate categories of methane (CH4) and non-methane (NMVOCs). Methane is an extremely efficient greenhouse gas which contributes to global warming. Other hydrocarbon VOCs are also significant greenhouse gases because they create ozone and they lengthen the life of methane in the atmosphere, although the effect varies depending on local air quality. Within the NMVOCs, the aromatic compounds benzene, toluene and xylene are suspected carcinogens and may lead to leukemia through prolonged exposure. 1,3-butadiene is another dangerous compound which is often associated with industrial uses.
•    Particulate matter - Particulates, alternatively referred to as particulate matter (PM) or fine particles, are tiny particles of solid or liquid suspended in a gas. In contrast, aerosol refers to particles and the gas together. Sources of particulate matter can be man made or natural. Some particulates occur naturally, originating from volcanoes, dust storms, forest and grassland fires, living vegetation, and sea spray. Human activities, such as the burning of fossil fuels in vehicles, power plants and various industrial processes also generate significant amounts of aerosols. Averaged over the globe, anthropogenic aerosols—those made by human activities—currently account for about 10 percent of the total amount of aerosols in our atmosphere. Increased levels of fine particles in the air are linked to health hazards such as heart disease, altered lung function and lung cancer.
•    Toxic metals, such as lead, cadmium and copper.
•    Chlorofluorocarbons (CFCs) - harmful to the ozone layer emitted from products currently banned from use.
•    Ammonia (NH3) - emitted from agricultural processes. Ammonia is a compound with the formula NH3. It is normally encountered as a gas with a characteristic pungent odor. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to foodstuffs and fertilizers. Ammonia, either directly or indirectly, is also a building block for the synthesis of many pharmaceuticals. Although in wide use, ammonia is both caustic and hazardous.
•    Odors — such as from garbage, sewage, and industrial processes.
•    Radioactive pollutants - produced by nuclear explosions, war explosives, and natural processes such as the radioactive decay of radon.

Secondary pollutants include:

•    Particulate matter formed from gaseous primary pollutants and compounds in photochemical smog. Smog is a kind of air pollution; the word "smog" is a portmanteau of smoke and fog. Classic smog results from large amounts of coal burning in an area caused by a mixture of smoke and sulfur dioxide. Modern smog does not usually come from coal but from vehicular and industrial emissions that are acted on in the atmosphere by sunlight to form secondary pollutants that also combine with the primary emissions to form photochemical smog.
•    Ground level ozone (O3) formed from NOx and VOCs. Ozone (O3) is a key constituent of the troposphere (it is also an important constituent of certain regions of the stratosphere commonly known as the Ozone layer). Photochemical and chemical reactions involving it drive many of the chemical processes that occur in the atmosphere by day and by night. At abnormally high concentrations brought about by human activities (largely the combustion of fossil fuels), it is a pollutant, and a constituent of smog.
•    Peroxyacetyl nitrate (PAN) - similarly formed from NOx and VOCs.

Minor air pollutants include:

•    A large number of minor hazardous air pollutants. Some of these are regulated in USA under the Clean Air Act and in Europe under the Air Framework Directive.
•    A variety of persistent organic pollutants, which can attach to particulate matter.
Persistent organic pollutants (POPs) are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic processes. Because of this, they have been observed to persist in the environment, to be capable of long-range transport, bioaccumulate in human and animal tissue, biomagnify in food chains, and to have potential significant impacts on human health and the environment.

Source: Wikipedia

Resulting from or produced by human actions.

The atmosphere is the gaseous envelope surrounding the Earth. The dry atmosphere consists almost entirely of nitrogen (78.1% volume mixing ratio) and oxygen (20.9% volume mixing ratio), together with a number of trace gases, such as argon (0.93% volume mixing ratio), helium and radioactive greenhouse gases such as carbon dioxide (0.035% volume mixing ratio) and ozone. In addition, the atmosphere contains the greenhouse gas water vapor, in amounts that are highly variable, but typically around 1% volume mixing ratio. The atmosphere also contains clouds and aerosols.

The bamboos are a group of woody perennial evergreen (except for certain temperate species) plants in the true grass family Poaceae, subfamily Bambusoideae, tribe Bambuseae. Some are giant bamboos, the largest members of the grass family. Bamboos are the fastest growing woody plants in the world. Their growth rate (up to 60 centimeters (24 in.)/day) is due to a unique rhizome-dependent system, but is highly dependent on local soil and climate conditions. They are of high economic and cultural significance in East Asia and South East Asia, where they are used extensively in gardens, as a building material, and as a food source.

There are more than 70 genera divided into about 1,000 species. They are found in diverse climates, from cold mountains to hot tropical regions. They occur across East Asia, from 50°N latitude in Sakhalin through to Northern Australia, and west to India and the Himalayas. They also occur in sub-Saharan Africa, and in the Americas from the Mid-Atlantic United States south to Argentina and Chile, reaching their southernmost point anywhere, at 47°S latitude. Major areas with no native bamboos include Europe and Antarctica.

Bamboo is the fastest-growing plant on Earth; it has been measured surging skyward as fast as 121 cm (47.6 inches) in a 24-hour period, and can also reach maximal growth rate exceeding one meter (39 inches) per hour for short periods of time. Many prehistoric bamboos exceeded heights of 75 meters (250 feet). Primarily growing in regions of warmer climates during the Cretaceous period, vast fields existed in what is now Asia.

Unlike trees, all bamboos grow to full height and girth in a single growing season of 3–4 months. During this first season, the clump of young shoots grows vertically, with no branching. In the next year, the pulpy wall of each culm slowly dries and hardens. The culm begins to sprout branches and leaves from each node. During the third year, the culm further hardens. The shoot is now considered a fully mature culm. Over the next 2–5 years (depending on species), fungus and mould begin to form on the outside of the culm, which eventually penetrate and overcome the culm. Around 5 – 8 years later (species and climate dependent), the fungal and mold growth cause the culm to collapse and decay. This brief life means culms are ready for harvest and suitable for use in construction within 3 – 7 years.

Textiles

There are two methods by which bamboo may be processed into fiber for fabric, both developed in China. The first is a mechanical process similar to that used to process flax or hemp; the stalks are crushed and natural enzymes break them down further, allowing fibers to be combed out. The other follows the process by which rayon is made; the fibers are broken down with chemicals and extruded through mechanical spineretes. The chemicals include lye, carbon disulfide and strong acids. Retailers have sold both end products as "bamboo fabric" to cash in on bamboo's current eco-friendly cachet.

However, the Canadian Competition Bureau and the US Federal Trade Commission, as of mid-2009, are cracking down on the practice of labeling bamboo rayon as natural bamboo fabric. Under the guidelines of both agencies, these products must be labeled as rayon with the optional qualifier "from bamboo". Bamboo fabric is known for its softness and boasts strong absorbency and anti-microbial properties, though the chemical process in bamboo rayon destroys any anti-microbial quality.

Several institutes, businesses, and universities are working on the bamboo as an ecological construction material. In the United States and France, it is possible to get houses made entirely of bamboo, which are earthquake and cyclone-resistant and internationally certified. In Bali, Indonesia, there is an international primary school, named the Green School, which is constructed entirely of bamboo, due to its beauty, and advantages as a sustainable resource. There are three ISO standards for bamboo as a construction material.

Source: Wikipedia

Biodegradation is material breakdown into chemicals by a physiological environment. The term is often used in relation to ecology, waste management and environmental remediation (bioremediation). Organic material can be degraded aerobically with oxygen, or anaerobically, without oxygen. A term related to biodegradation is biomineralization, in which organic matter is converted into minerals. Biosurfactant, an extracellular surfactant secreted by microorganisms, enhances the biodegradation process.

Biodegradable matter is generally organic material such as plant and animal matter and other substances originated from living organisms, or artificial materials that are similar enough to plant and animal matter to be put to use by microorganisms. Some microorganisms have the astonishing, naturally occurring, microbial catabolic diversity to degrade, transform or accumulate a huge range of compounds including hydrocarbons (e.g. oil), polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs), pharmaceutical substances, radionuclides and metals.

Major methodological breakthroughs in microbial biodegradation have enabled detailed genomic, metagenomic, proteomic, bioinformatic and other high-throughput analyses of environmentally relevant microorganisms providing unprecedented insights into key biodegradative pathways and the ability of microorganisms to adapt to changing environmental conditions.

Decomposition time for different substances:
Banana peel: up to 10 days
Paper: 2 to 5 months
Orange peel: 5 months
Cigarette filters: 2 to 5 years
Plastic: 20 years
Nylon cloth: 30 to 40 years
Disposable Styrofoam cups: up to 100 years
Aluminum: from 300 to 500 years
Glass bottle: close to 4,000 years
This list shows the importance of recycling materials, especially plastics and glass.

Source: Wikipedia

Biofuel is defined as solid, liquid or gaseous fuel obtained from relatively recently lifeless or living biological material and is different from fossil fuels, which are derived from long dead biological material. Also, various plants and plant-derived materials are used for biofuel manufacturing.
Globally, biofuels are most commonly used to power vehicles, heat homes, and for cooking. Biofuel industries are expanding in Europe, Asia and America. Recent technology, developed at Los Alamos National Lab, even allows for the conversion of pollution into renewable bio fuel. Agrofuels are biofuels which are produced from specific crops, rather than from waste processes such as landfill off-gassing or recycled vegetable oil.
There are two common strategies of producing liquid and gaseous agrofuels. One is to grow crops high in sugar (sugar cane, sugar beet, and sweet sorghum) or starch (corn/maize), and then use yeast fermentation to produce ethyl alcohol (ethanol). The second is to grow plants that contain high amounts of vegetable oil, such as oil palm, soybean, algae, jatropha, or pongamia pinnata. When these oils are heated, their viscosity is reduced, and they can be burned directly in a diesel engine, or they can be chemically processed to produce fuels such as biodiesel. Wood and its byproducts can also be converted into biofuels such as woodgas, methanol or ethanol fuel. It is also possible to make cellulosic ethanol from non-edible plant parts, but this can be difficult to accomplish economically.

Source: Wikipedia

There are two definitions for Biomass.
The first is:
The total mass of living organisms in a given area or volume; recently dead plant material is often included as dead biomass. The quantity of biomass is expressed as a dry weight or as its energy, carbon, or nitrogen content. This is difficult to measure in terms of ecosystems.
The second definition is:
A renewable energy source,  it is the biological material derived from living, or recently living organisms, such as wood, waste, and alcohol fuels. Biomass is commonly plant matter grown to generate electricity or produce heat. For example, forest residues (such as dead trees, branches and tree stumps), yard clippings and wood chips may be used as biomass. However, biomass also includes plant or animal matter used for production of fibers or chemicals. Biomass may also include biodegradable wastes that can be burnt as fuel. It excludes organic material such as fossil fuel which has been transformed by geological processes.

Biomes are climatically and geographically defined areas of similar ecologic and climatic conditions, such as communities of plants, animals, and soil organisms, and are often referred to as ecosystems. Biomes are defined by factors such as plant structures (such as trees, shrubs, and grasses), leaf types (such as broadleaf and needleleaf), plant spacing (forest, woodland, savanna), and climate.

Unlike ecozones, biomes are not defined by genetic, taxonomic, or historical similarities. Biomes are often identified with particular patterns of ecological succession and climax vegetation (quasi-equilibrium state of the local ecosystem). An ecosystem has many biotopes and a biome is a major habitat type. A major habitat type, however, is a compromise, as it has an intrinsic inhomogeneity.

The biodiversity characteristic of each biome, especially the diversity of fauna and subdominant plant forms, is a function of abiotic factors and the biomass productivity of the dominant vegetation. In terrestrial biomes, species diversity tends to correlate positively with net primary productivity, moisture availability, and temperature.
Ecoregions are grouped into both biomes and ecozones.
A fundamental classification of biomes is into:
1.    Terrestrial (land) biomes
2.    Freshwater biomes
3.    Marine biomes
Biomes are often known in English by local names. For example, a Temperate grassland or shrubland biome is known commonly as steppe in central Asia, prairie in North America, and pampas in South America. Tropical grasslands are known as savanna in Australia, whereas in Southern Africa it is known as veldt (from Afrikaans).
Sometimes an entire biome may be targeted for protection, especially under an individual nation's Biodiversity Action Plan.
Climate is a major factor determining the distribution of terrestrial biomes. Among the important climatic factors are:
•    latitude: Arctic, boreal, temperate, subtropical, tropical.
•    humidity: humid, semi-humid, semi-arid, and arid.
•    seasonal variation: Rainfall may be distributed evenly throughout the year or be marked by seasonal variations.
•    dry summer, wet winter: Most regions of the Earth receive most of their rainfall during the summer months; Mediterranean climate regions receive their rainfall during the winter months.
•    elevation: Increasing elevation causes a distribution of habitat types similar to that of increasing latitude.
The most widely used systems of classifying biomes correspond to latitude (or temperature zoning) and humidity. Biodiversity generally increases away from the poles towards the equator and increases with humidity.

Source: Wikipedia

The part of the Earth system comprising all ecosystems and living organisms, in the atmosphere, on land (terrestrial biosphere) or in the oceans (marine biosphere), including derived dead organic matter, such as litter, soil organic matter and oceanic detritus.

The Blue Angel (Blauer Engel) is a German certification for products and services that have environmentally friendly aspects.
The certificate has been awarded since 1978 by the Jury Umweltzeichen, a group of 13 persons from environment and consumer protection groups, industry, unions, trade, media and churches.
After the introduction of Germany’s Blue Angel in 1978 as the first worldwide environmental label, other European and non-European countries followed this example and introduced their own national and supra-regional environmental labels. The common goal of these labels is to inform consumers about environmentally friendly products, thereby giving global support to product-related environmental protection.
In 1994, some countries cooperated in developing the Global Ecolabelling Network (GEN) - a non-profit interest group composed of ecolabel organizations throughout the world.

Source: Wikipedia

Blue energy, also called osmotic power or salinity gradient power, is the energy retrieved from the difference in the salt concentration between seawater and river water. Two practical methods for this are reverse electrodialysis (RED), and pressure retarded osmosis (PRO).

Both processes rely on osmosis with ion specific membranes. The key waste product is brackish water. This byproduct is the result of natural forces that are being harnessed: the flow of fresh water into seas that are made up of salt water.

Source: Wikipedia

The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth. It is one of the most important cycles of the Earth and allows for the most abundant element to be recycled and reused throughout the biosphere and all of its organisms.

The carbon cycle is usually thought of as four major reservoirs of carbon interconnected by pathways of exchange. These reservoirs are:
    The atmosphere
    The terrestrial biosphere, which is usually defined to include fresh water systems and non-living organic material, such as soil carbon
    The oceans, including dissolved inorganic carbon and living and non-living marine biota,
    The sediments including fossil fuels.

The annual movements of carbon, the carbon exchanges between reservoirs, occur because of various chemical, physical, geological, and biological processes. The ocean contains the largest active pool of carbon near the surface of the Earth, but the deep ocean part of this pool does not rapidly exchange with the atmosphere.

The global carbon budget is the balance of the exchanges (incomes and losses) of carbon between the carbon reservoirs or between one specific loop (e.g., atmosphere ? biosphere) of the carbon cycle. An examination of the carbon budget of a pool or reservoir can provide information about whether the pool or reservoir is functioning as a source or sink for carbon dioxide.

Source: Wikipedia

Carbon dioxide is a gas that is produced naturally and also as a product of burning fossil fuels and biomass, changes in the use of the Earth, and other industrial processes. It is the main anthropogenic greenhouse gas that affects the radiation balance of the planet. It is the reference gas by which other greenhouse gases are measured.

A carbon footprint is the total set of greenhouse gas (GHG) emissions caused directly and indirectly by an individual, organization, event or product. For simplicity of reporting, it is often expressed in terms of the amount of carbon dioxide, or its equivalent of other GHGs, emitted.

The concept and name of the carbon footprint originates from the ecological footprint discussion. The carbon footprint is a subset of the ecological footprint.

An individual, nation, or organization's carbon footprint can be measured by undertaking a GHG emissions assessment. Once the size of a carbon footprint is known, a strategy can be devised to reduce it.

The mitigation of carbon footprints through the development of alternative projects, such as solar or wind energy or reforestation, represents one way of reducing a carbon footprint and is often known as Carbon offsetting.

Source: Wikipedia

Organic certification is a certification process for producers of organic food and other organic agricultural products. In general, any business directly involved in food production can be certified, including seed suppliers, farmers, food processors, retailers and restaurants. Requirements vary from country to country, and generally involve a set of production standards for growing, storage, processing, packaging and shipping that include:

•   avoidance of most synthetic chemical inputs (e.g. fertilizer, pesticides, antibiotics, food additives, etc), genetically modified organisms, irradiation, and the use of sewage sludge;
•   use of farmland that has been free from chemicals for a number of years (often, three or more);
•   keeping detailed written production and sales records (audit trail);
•   maintaining strict physical separation of organic products from non-certified products;
•   undergoing periodic on-site inspections.

In some countries, certification is overseen by the government, and commercial use of the term organic is legally restricted. Certified organic producers are also subject to the same agricultural, food safety and other government regulations that apply to non-certified producers.

This is a family of chemical products that contain chlorine, fluoride, and carbon. They are used as coolants, aerosol propellants, cleaning solvents, and in the manufacture of foams. Although is was initially considered to be harmless, we now know that it accumulates in the atmosphere, where it destroys the protective ozone layer and retains solar rays, which contributes to the greenhouse effect.
The most common CFCs are CFC-11, CFC-12, CFC-113, CFC-114, and CFC-115. These gases are included in the 1987 Montreal Protocol list of Greenhouse gases.
These gases are being substituted for other compounds, including hydrochlorofluorocarbons and hydrofluorocarbons, which are listed as greenhouse gases by the Kyoto Protocol.

Climate change refers to a change in the state of the climate that can be identified (e.g., by using statistical tests) by changes in the mean and/or the variability of its properties, and that persists for an extended period, typically decades or longer. Climate change may be due to natural internal processes or external force, or to persistent anthropogenic changes in the composition of the atmosphere or in land use.

Note that the United Nations Framework Convention on Climate Change (UNFCCC), in its Article 1, defines climate change as: “a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods.” The UNFCCC thus makes a distinction between climate change attributable to human activities altering the atmospheric composition, and climate variability attributable to natural causes.

Compost is a combination of food waste and brown waste that is being decomposed through aerobic decomposition into a rich black soil. The process of composting is simple and practiced by individuals in their homes, farmers on their land, and industrially by cities.

Compost soil is very rich soil and used for many purposes. A few of the places where it is used include gardens, landscaping, horticulture, and agriculture. The compost soil itself is beneficial for the land in many ways, such as a soil conditioner, a fertilizer to add vital humus or humic acids, and as a natural pesticide for soil. In ecosystems, compost soil is useful for erosion control, land and stream reclamation, wetland construction, and as landfill cover.

Given enough time, all biodegradable material will oxidize to compost. One objective of composting today is to treat readily degradable materials that may otherwise enter landfills, and decompose anaerobically, releasing greenhouse gases. Most small-scale domestic systems are not maintained at the thermophilic temperatures required to eliminate possible pathogens and disease vectors, or deter vermin, therefore pet droppings, meat scrap, and dairy products are best left to larger scale high-rate, aerobic composting systems. A local green waste recycling facility may operate such a system. However, hobby animal manure (horses, goats, sheep, and chickens), fruit and vegetable food waste and garden waste are excellent raw materials for home composting.

As concern about landfill space increases, worldwide interest in recycling by means of composting is growing, since composting is a process for converting decomposable organic wastes into useful stable products.

Source: Wikipedia

Conservation agriculture involves several practices that allow for the use of the ground for agriculture with minimal alteration in its composition, structure, and natural biodiversity. At the same time, it protects degradation processes such as erosion and compactation.

Some strategies that are included within conservation agriculture are minimal tilling, direct sowing, incorporation of vegetable cover, crop rotation, irrigation control to reduce erosion from water or the selection of species and spaces appropriate for cultivation.

Cotton is a soft, staple fiber that grows (in a form known as a boll) around the seeds of the cotton plant, a shrub native to tropical and subtropical regions around the world, including the Americas, India and Africa. The fiber most often is spun into yarn or thread and used to make a soft, breathable textile, and is the most widely used natural-fiber cloth in clothing today.

Successful cultivation of cotton requires a long frost-free period, plenty of sunshine, and a moderate rainfall, usually from 600 to 1200 mm (24 to 48 inches). Soils usually need to be fairly heavy, although the level of nutrients does not need to be exceptional. In general, these conditions are met within the seasonally dry tropics and subtropics in the Northern and Southern hemispheres, but a large proportion of the cotton grown today is cultivated in areas with less rainfall, that obtain the water from irrigation.

Production of the crop for a given year usually starts soon after harvesting, the preceding autumn. Planting time in spring in the Northern hemisphere varies from the beginning of February to the beginning of June. The area of the United States known as the South Plains is the largest contiguous cotton-growing region in the world. It is heavily dependent on irrigation water drawn from the Ogallala Aquifer.

The cotton industry relies heavily on chemicals such as fertilizers and insecticides. However, a very small number of farmers are moving toward an organic model of production, and organic cotton products are now available for purchase at limited locations. These are popular for baby clothes and diapers. Under most definitions, organic products do not use genetic engineering.

Genetically modified cotton

Genetically modified (GM) cotton was developed to reduce the heavy reliance on pesticides. The bacterium Bacillus thuringiensis naturally produces a chemical harmful only to a small fraction of insects, most notably the larvae of moths and butterflies, beetles, and flies, and harmless to other forms of life. The gene coding for BT toxin has been inserted into cotton, causing cotton to produce this natural insecticide in its tissues.

In many regions the main pests in commercial cotton are lepidopteran larvae, which are killed by the BT protein in the transgenic cotton that they eat. This eliminates the need to use large amounts of broad-spectrum insecticides to kill lepidopteran pests (some of which have developed pyrethroid resistance). This spares natural insect predators in the farm ecology and further contributes to non-insecticide pest management.

On the other hand, BT cotton is ineffective against many cotton pests, such as plant bugs, stink bugs, aphids, etc.; depending on circumstances it may still be desirable to use insecticides against these.

Genetically modified cotton is widely used throughout the world. Nevertheless, researchers have recently published the first documented case of in-field pest resistance to GM cotton. The International Service for the Acquisition of Agri-biotech Applications (ISAAA) said that, worldwide, GM cotton was planted on an area of 67,000 km² in 2002. This is 20% of the worldwide total area planted in cotton. The U.S. cotton crop was 73% GM in 2003.

The initial introduction of GM cotton proved to be a commercial and ecological disaster in Australia - the yields were far lower than predicted, and the cotton plants were cross-pollinated with other varieties of cotton. However, the introduction of a second variety of GM cotton led to 15% of Australian cotton being GM in 2003. 80% of the crop was genetically modified in 2004, when the original GM variety was banned.

Cotton has also been genetically modified for resistance to glyphosate (marketed as Roundup in North America), an inexpensive and highly effective but broad-spectrum herbicide. Originally, it was only possible to achieve glyphosate resistance when the plant was young, but with the development of Roundup Ready Flex, it is possible to achieve Glyphosate resistance much later in the growing season.

GM cotton acreage in India continues to grow at a rapid rate increasing from 50,000 hectares in 2002 to 3.8 million hectares in 2006. The total cotton area in India is about 9.0 million hectares (the largest in the world or, about 25% of world cotton area) so GM cotton is now grown on 42% of the cotton area. This makes India the country with the largest area of GM cotton in the world, surpassing China (3.5 million hectares in 2006). The major reasons for this increase is a combination of increased farm income ($225/ha) and a reduction in pesticide use to control the Cotton Bollworm.

Cotton has gossypol, a toxin that makes it inedible. However, scientists have silenced the gene that produces the toxin, making it a potential food crop.

Organic cotton

Organic cotton is cotton that is grown without chemical fertilizers, insecticide or pesticide. According to the World Health Organization (WHO), 20,000 deaths occur each year from pesticide poisoning in developing countries, many of these from cotton farming. Organic agriculture uses methods that are ecological, economical, and socially sustainable and denies the use of agrochemicals and artificial fertilizers. Instead, organic agriculture uses crop rotation, the growing of different crops than cotton in alternative years. The use of insecticides is prohibited; organic agriculture uses natural enemies to suppress harmful insects.

The production of organic cotton is more expensive than the production of conventional cotton. Although toxic pollution from synthetic chemicals is eliminated, other pollution-like problems may remain, particularly run-off and additional use of fossil fuels. Organic cotton is produced in organic agricultural systems that produce food and fiber according to clearly established standards. Organic agriculture prohibits the use of toxic and persistent chemical pesticides and fertilizers, as well as genetically modified organisms. It seeks to build biologically diverse agricultural systems, replenish and maintain soil fertility, and promote a healthy environment.

Source: Wikipedia

A crystal is a solid material with an atomic structure that is organized in three dimensions, meaning that it is formed by the repetition of atoms, ions, or molecules. Except for glass and other amorphous substances, all solid material is in a crystalline state.

Earth Day is celebrated in the US on April 22 and is a day designed to inspire awareness and appreciation for the Earth's environment. It was founded by U.S. Senator Gaylord Nelson (D-Wisconsin) as an environmental teach-in in 1970, and is celebrated in many countries every year. This date is during spring in the Northern Hemisphere and Autumn in the Southern Hemisphere.

The United Nations celebrates an Earth Day each year on the March equinox, which is often March 20, a tradition which was founded by peace activist John McConnell in 1969.

Source: Wikipedia

A measure of how much biologically productive land and water an individual, population or activity requires to produce all the resources it consumes and to absorb the waste it generates using prevailing technology and resource management practices. The Ecological Footprint is usually measured in global hectares. Because trade is global, an individual or country's footprint includes land or sea from all over the world.

The Ecological Footprint uses yields of primary products (from cropland, forest, grazing land and fisheries) to calculate the area necessary to support a given activity. Biocapacity is measured by calculating the amount of biologically productive land and sea area available to provide the resources a population consumes and to absorb its wastes, given current technology and management practices. Countries differ in the productivity of their ecosystems, and this is reflected in the accounts.

A nation’s consumption is calculated by adding imports to and subtracting exports from its national production. Results from this analysis shed light on a country’s ecological impact. For example, the National Footprint Accounts identify whether or not a country’s Ecological Footprint exceeds its biocapacity. A country has an ecological reserve if its Footprint is smaller than its biocapacity; otherwise it is operating with an ecological deficit. The former are often referred to as ecological creditors, and the latter ecological debtors.

Today, most countries, and the world as a whole, are running ecological deficits. The world’s ecological deficit is referred to as global ecological overshoot.

Ecology is the study of living beings, their environment, distribution, and abundance, and the interaction of these organisms with their environment. The environment includes physical properties that can be described as the sum of local abiotic factors, such as climate and geology, and other organisms that share this habitat (biotic factors.)

Ecology analyzes how each element of an ecosystem affects the other components and how it is affected. It is a comprehensive science, because to understand an ecosystem, you must have knowledge of botany, zoology, physiology, genetics, and other disciplines like physics, chemistry, and geology.

An ecosystem is a natural unit that consists of all the plants, animals, and microorganisms (biotic factors) of an area working together with all of the non-living (abiotic) factors of the environment. An ecosystem is a unit made up of interdependent organisms that share the same habitat.

The limits of an ecosystem are somewhat arbitrary, and they depend on the particular focus or study. Therefore, an ecosystem can vary from a very small scale up to including the entire planet.

Substance that when in solution or in a liquid state conducts electric current due to its free ions.

Electronic waste, e-waste, e-scrap, or Waste Electrical and Electronic Equipment (WEEE) describes loosely discarded, surplus, obsolete, broken, electrical or electronic devices. The processing of electronic waste in developing countries causes serious health and pollution problems because electronic equipment contains some very serious contaminants such as lead, cadmium, beryllium and brominated flame retardants. Even in developed countries recycling and disposal of e-waste involves significant risk for example to workers and communities and great care must be taken to avoid unsafe exposure in recycling operations and leaching of materials such as heavy metals from landfills and incinerator ashes.

Source: Wikipedia

Emissions trading is an administrative approach used to control pollution by providing economic incentives for achieving reductions in the emissions of pollutants. It is sometimes called cap and trade or carbon off-set.

Due to emissions trading, coal may become less competitive as a fuel.

A central authority (usually a government or international body) sets a limit or cap on the amount of a pollutant that can be emitted. Companies or other groups are issued emission permits and are required to hold an equivalent number of allowances (or credits) which represent the right to emit a specific amount. The total amount of allowances and credits cannot exceed the cap, limiting total emissions to that level. Companies that need to increase their emission allowance must buy credits from those who pollute less. The transfer of allowances is referred to as a trade. In effect, the buyer is paying a charge for polluting, while the seller is being rewarded for having reduced emissions by more than was needed. Thus, in theory, those who can easily reduce emissions most cheaply will do so, achieving the pollution reduction at the lowest possible cost to society.

There are active trading programs in several pollutants. For greenhouse gases the largest is the European Union Emission Trading Scheme. In the United States there is a national market to reduce acid rain and several regional markets in nitrogen oxides. Markets for other pollutants tend to be smaller and more localized.

Source: Wikipedia

Energy Star is an international standard for energy efficient consumer products. It was first created as a United States government program in 1992, but Australia, Canada, Japan, New Zealand, Taiwan and the European Union have also adopted the program. Devices carrying the Energy Star logo, such as computer products and peripherals, kitchen appliances, buildings and other products, save 20%-30% on average. However, many European-targeted products are labeled using a different standard, TCO Certification, a combined energy usage and ergonomics rating from the Swedish Confederation of Professional Employees (TCO) instead of Energy Star.

The ENERGY STAR program was created in 1992 by the United States Environmental Protection Agency in an attempt to reduce energy consumption and greenhouse gas emission by power plants. The program was developed by John S. Hoffman, inventor of the Green Programs at US EPA, and implemented by Cathy Zoi and Brian Johnson. The program was intended to be part of a series of voluntary programs, such as Green Lights and the Methane Programs, that would demonstrate the potential profits in reducing greenhouse gases and facilitate further steps to reducing global warming gases.

Initiated as a voluntary labeling program designed to identify and promote energy efficient products, ENERGY STAR began with labels for computer products. In 1995 the program was significantly expanded, introducing labels for residential heating and cooling systems and new homes. As of 2006, more than 40,000 ENERGY STAR products are available in a wide range of items including major appliances, office equipment, lighting, home electronics, and more. In addition, the label can also be found on new homes and commercial and industrial buildings. In 2006, about 12 percent of new housing in the United States was labeled ENERGY STAR.

The EPA estimates that it saved about $14 billion in energy costs in 2006 alone. The ENERGY STAR program has helped spread the use of LED traffic lights, efficient fluorescent lighting, power management systems for office equipment, and low standby energy use.

Source: Wikipedia

The Environmental Protection Agency (commonly called by its initials EPA) is a federal government agency of the United States that is responsible for protecting human health and the environment: air, water, and ground. It was established in 1970.

The EPA establishes directives to help citizens keep the environment cleaner. This organization also contributes to repairing damage that has already affected the world.

The largest single use of ethanol is as a motor fuel and fuel additive. Brazil has the largest national fuel ethanol industry. Gasoline sold in Brazil contains at least 25% anhydrous ethanol. Hydrous ethanol (about 95% ethanol and 5% water) can be used as fuel in more than 90% of new cars sold in the country. Brazilian ethanol production is praised for the high carbon sequestration capabilities of the sugar cane plantations, thus making it a real option to combat climate change.

Henry Ford designed the first mass-produced automobile, the famed Model T Ford, to run on pure anhydrous (ethanol) alcohol - he said it was "the fuel of the future". Today, however, 100% pure ethanol is not approved as a motor vehicle fuel in the U.S. Added to gasoline, ethanol reduces volatile organic compound and hydrocarbon emissions, carcinogenic benzene and butadiene emissions, and particulate matter emissions from gasoline combustion.

Ethanol combustion in an internal combustion engine yields many of the products of incomplete combustion produced by gasoline and significantly larger amounts of formaldehyde and related species such as acetaldehyde. This leads to a significantly larger photochemical reactivity that generates much more ground level ozone. This data has been assembled into The Clean Fuels Report comparison of fuel emissions and shows that ethanol exhaust generates 2.14 times as much ozone as does gasoline exhaust. When this is added into the custom "Localized Pollution Index (LPI)" of The Clean Fuels Report the local pollution, i.e. that which contributes to smog, is 1.7 on a scale where gasoline is 1.0 and higher numbers signify greater pollution.

This issue has been formalized by the California Air Resources Board in 2008 by recognizing control standards for formaldehydes as an emissions control group much like the conventional NOx and Reactive Organic Gases (ROGs).

Source: WIkipedia

Externalities are produced when the actions of one economic agent affect another directly, but not through the price system. Externalities can be negative or positive. A negative externality comes about when a concrete action injures a third party or the environment, but is not compensated for it.

Fair trade is an organized social movement and market-based approach that aims to help producers in developing countries and promote sustainability. The movement advocates the payment of a higher price to producers as well as social and environmental standards in areas related to the production of a wide variety of goods. It focuses in particular on exports from developing countries to developed countries, most notably handicrafts, coffee, cocoa, sugar, tea, bananas, honey, cotton, wine, fresh fruit, chocolate and flowers.

Fair trade's strategic aim is to work with marginalized producers and workers in order to help them move towards economic self-sufficiency and stability. It also aims to allow them to become greater stakeholders in their own organizations, as well as play a wider role in international trade. Fair trade proponents include a number of international development aid, social, religious and environmental organizations such as Christian Aid, SERRV International, Oxfam, Amnesty International, Catholic Relief Services, and Caritas International.

Fair trade advocates typically adopt a number of guidelines. The movement intends to provide market access to otherwise marginalized producers, connecting them to customers and allowing access with fewer middlemen. It aims to provide higher wages than typically paid to producers as well as helping producers develop knowledge, skills and resources to improve their lives. Fair trade advocates also seek to raise awareness of the movement's philosophies among consumers in developed nations. Fair trade products are traded and marketed either by an "integrated supply chain" whereby products are imported and/or distributed by fair trade organizations (commonly referred to as alternative trading organizations) or by "product certification" whereby products complying with fair trade specifications are certified indicating that they have been produced, traded, processed and packaged in accordance with the standards.

Source: Wikipedia

There are three fossil fuels: petroleum, coal, and natural gas, and these were formed millions of years ago from the organic remains of dead plants and animals. For thousands of years, the remains of the beings that populated the Earth during various stages were deposited at the bottom of the oceans, lakes, and other bodies of water and covered by layers of sediment. Millions of years were needed for the chemical decomposition reactions to take place. The weight of these layers transformed the organic remains into gas, petroleum, or coal.

Fossil fuels are non-renwable resources. At some point they will run out, and it may take millions of years to get them back.

Most of the energy used currently in the world comes from fossil fuels. They are used for transportation, to generate electricity, to heat buildings, to cook, and in practically all aspects of modern life.

Soon the costs of extraction and refining fossil fuels will go up since it will be more difficult to obtain petroleum from the Earth. Fossil fuels that took millions of years to form have been burned in just 100 years, which contributes directly to global warming. Replacing fossil fuels with renewable energy will provide a cleaner atmosphere, a reduction in greenhouse gas emissions, and a more sustainable future.

In chemistry, radicals (often referred to as free radicals) are atoms, molecules, or ions with unpaired electrons on an otherwise open shell configuration. These unpaired electrons are usually highly reactive, so radicals are likely to take part in chemical reactions. Radicals play an important role in combustion, atmospheric chemistry, polymerization, plasma chemistry, biochemistry, and many other chemical processes, including human physiology. For example, superoxide and nitric oxide regulate many biological processes, such as controlling vascular tone. "Radical" and "free radical" are frequently used interchangeably, although a radical may be trapped within a solvent cage or be otherwise bound. The first organic free radical identified was triphenylmethyl radical, by Moses Gomberg in 1900 at the University of Michigan.

Historically, the term radical has also been used for bound parts of the molecule, especially when they remain unchanged in reactions. These are now called functional groups. For example, methyl alcohol was described as consisting of a methyl "radical" and a hydroxyl "radical". Neither are radicals in the modern chemical sense, as they are permanently bound to each other, and have no unpaired, reactive electrons. They can, however, be observed as radicals in mass spectrometry after breaking down the substance with a hail of energetic electrons.

Source: Wikipedia

The Gaia hypothesis is an ecological hypothesis proposing that the biosphere and the physical components of the Earth (atmosphere, cryosphere, hydrosphere and lithosphere) are closely integrated to form a complex interacting system that maintains the climatic and biogeochemical conditions on Earth in a preferred homeostasis. Originally proposed by James Lovelock as the Earth feedback hypothesis, it was named—at the suggestion of his neighbor William Golding—the Gaia Hypothesis, after the Greek supreme goddess of Earth. The hypothesis is frequently described as viewing the Earth as a single organism. Lovelock and other supporters of the idea now call it Gaia theory, regarding it as a scientific theory and not mere hypothesis, since they believe it has passed predictive tests.

Source: Wikipedia

Genetic engineering, recombinant DNA technology, genetic modification/manipulation (GM) and gene splicing are terms that apply to the direct manipulation of an organism's genes. Genetic engineering is different from traditional breeding, where the organism's genes are manipulated indirectly. Genetic engineering uses the techniques of molecular cloning and transformation to alter the structure and characteristics of genes directly. Genetic engineering techniques have found some successes in numerous applications. Some examples are the improvement of crop technology, the manufacture of synthetic human insulin through the use of modified bacteria, the manufacture of erythropoietin in hamster ovary cells, and the production of new types of experimental mice such as the oncomouse (cancer mouse) for research.

Source: Wikipedia

Geothermal power (from the Greek roots geo, meaning earth, and thermos, meaning heat) is power extracted from heat stored in the Earth. This geothermal energy originates from the original formation of the planet, from radioactive decay of minerals, and from solar energy absorbed at the surface. It has been used for space heating and bathing since ancient Roman times, but is now better known for generating electricity. Worldwide, geothermal plants have the capacity to generate about 10 GW as of 2007, and in practice generate 0.3% of global electricity demand. An additional 28 GW of direct geothermal heating capacity is installed for district heating, space heating, spas, industrial processes, desalination and agricultural applications.

Geothermal power is cost effective, reliable, and environmentally friendly, but has historically been limited to areas near tectonic plate boundaries. Recent technological advances have dramatically expanded the range and size of viable resources, especially for applications such as home heating, opening a potential for widespread exploitation. Geothermal wells release greenhouse gases trapped deep within the earth, but these emissions are much lower per energy unit than those of conventional fossil fuels. As a result, geothermal power has the potential to help mitigate global warming if widely deployed in place of fossil fuels.

Source: Wikipedia

The Earth is warming. It has warmed about 1.4º F in the last 100 years. The rate of change is increasing and is projected to go up another 7º by the end of this century. The warming will bring climate change. In some areas there will be more rain. Extreme weather can be expected, including more powerful and frequent storms. Tropical areas will grow; and, with the growth, drought is expected. Ice will melt and sea levels will rise. Some of these effects can already be seen in the retreat of glaciers at the poles and on the highest mountains.

Scientists say that the current period of global warming is due to increased greenhouse gas concentrations, especially CO2 caused by burning fossil fuels. It can be mitigated by moving toward a Low Carbon Economy, an economy that relies more on alternative energy sources and less on combustion for energy generation.

Global warming feeds itself. Water vapor is the most important greenhouse gas. Without water vapor to help raise the average temperature the Earth would be much colder, too cold to sustain life. But higher average temperatures caused by an increase of all greenhouse gases, particularly CO2, increase the evaporation of water. The evaporation increases the amount of water vapor in the atmosphere and creates a feedback loop of increased warming.

On the national and international level, policies to reduce the growth of CO2 emissions are in the works. On a personal level there are many ways for us to reduce our carbon footprint and reduce our contribution to global warming. They all start with reducing our reliance on fossil fuels.

It is a measure of how much a given mass of greenhouse gas is estimated to contribute to global warming. It is a relative scale which compares the gas in question to that of the same mass of carbon dioxide (whose GWP is by definition 1). A GWP is calculated over a specific time interval and the value of this must be stated whenever a GWP is quoted or else the value is meaningless.

Source: Wikipedia

The greenhouse effect is the heating of the surface of a planet or moon due to the presence of an atmosphere containing gases that absorb and emit infrared radiation. Thus, greenhouse gases trap heat within the surface-troposphere system. This mechanism is fundamentally different from that of an actual greenhouse, which works by isolating warm air inside the structure so that heat is not lost by convection.

The greenhouse effect was discovered by Joseph Fourier in 1824, first reliably experimented on by John Tyndall in 1858, and first reported quantitatively by Svante Arrhenius in 1896.

In the absence of the greenhouse effect and an atmosphere, the Earth's average surface temperature of 14 °C (57 °F) could be as low as ?18 °C (?0.4 °F), the black body temperature of the Earth. Anthropogenic global warming (AGW), a recent warming of the Earth's surface and lower atmosphere, is believed to be the result of an "enhanced greenhouse effect" mainly due to human-produced increases in atmospheric greenhouse gases.

Source: Wikipedia

Greenhouse gases are those gaseous constituents of the atmosphere, both natural and anthropogenic, that absorb and emit radiation at specific wavelengths within the spectrum of infrared radiation emitted by the Earth’s surface, the atmosphere, and clouds. This property causes the greenhouse effect. Water vapor (H2O), carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4), and ozone (O3) are the primary greenhouse gases in the Earth’s atmosphere. Moreover there are a number of entirely human-made greenhouse gases in the atmosphere, such as the halocarbons and other chlorine- and bromine-containing substances, dealt with under the Montreal Protocol. Besides CO2, N2O, and CH4, the Kyoto Protocol deals with the greenhouse gases sulfur hexafluoride (SF6), hydrofluorocarbons (HFCs), and perfluorocarbons (PFCs).

Hemp is the common name for plants of the entire genus Cannabis, although the term is often used to refer only to Cannabis strains cultivated for industrial (non-drug) use.

In modern times, industrial hemp has been tried for many uses, including paper, textiles, biodegradable plastics, construction, health food, and fuel, with modest commercial success. In the past three years, commercial success of hemp food products has grown considerably.

Hemp is one of the fastest growing biomasses known, producing up to 25 tons of dry matter per hectare per year, and one of the earliest domesticated plants known. For a crop, hemp is relatively environmentally friendly as it requires few pesticides and no herbicides.

Cannabis sativa L. subsp. sativa var. sativa is the variety grown for industrial use in Europe, Canada, and elsewhere, while C. sativa subsp. indica generally has poor fiber quality and is primarily used for production of recreational and medicinal drugs. The major difference between the two types of plants is the appearance and the amount of ?9-tetrahydrocannabinol (THC) secreted in a resinous mixture by epidermal hairs called glandular trichomes, although they can also be distinguished by genetic means. Strains of Cannabis approved for industrial hemp production produce only minute amounts of this psychoactive drug, not enough for any physical or psychological effects. Typically, hemp contains below 0.3% THC, while Cannabis grown for marijuana can contain anywhere from 6 or 7 % to 20% or even more.

Industrial hemp is produced in many countries around the world. Major producers include Canada, France, and China. While more hemp is exported to the United States than to any other country, the United States Government does not consistently distinguish between marijuana and the non-psychoactive Cannabis used for industrial and commercial purposes.

Hemp is used for a wide variety of purposes, including the manufacture of cordage of varying tensile strength, clothing, and nutritional products. The fibers can be used in 100% hemp products, but are commonly blended with other organic fibers such as flax, cotton or silk, for apparel and furnishings, most commonly at a 55%/45% hemp/cotton blend. The inner two fibers of hemp are woodier, and are more often used in non-woven items and other industrial applications, such as mulch, animal bedding and litter. The oil from the fruits ("seeds") dries on exposure to air (similar to linseed oil) and is sometimes used in the manufacture of oil-based paints, in creams as a moisturizing agent, for cooking, and in plastics. Hemp seeds have been used in bird seed mix. Hempseed is also widely used as fishing bait.

Food

Hemp seeds contain all the essential amino acids and essential fatty acids necessary to maintain healthy human life. The seeds can be eaten raw, ground into a meal, sprouted, made into hemp milk (akin to soy milk), prepared as tea, and used in baking. The fresh leaves can also be eaten in salads. Products range from cereals to frozen waffles, hemp tofu to nut butters. A few companies produce value added hemp seed items that include the seed oils, whole hemp grain, hulled hemp seed (the whole seed without the mineral rich outer shell), hemp flour, hemp cake (a by-product of pressing the seed for oil) and hemp protein powder. Hemp is also used in some organic cereals, for non-dairy milk somewhat similar to soy and nut milks, and for non-dairy hemp "ice cream."

The fiber is one of the most valuable parts of the hemp plant. It is commonly called bast, which refers to the fibers that grow on the outside of the woody interior of the plant's stalk, and under the outer most part (the bark). Fibers give the plants strength. Hemp fibers can be 0.91 m (3 ft) to 4.6 m (15 ft) long, running the length of the plant. Depending on the processing used to remove the fiber from the stem, the hemp may naturally be creamy white, brown, gray, black or green.

The use of hemp for fiber production has declined sharply over the last two centuries, but before the industrial revolution, hemp was a popular fiber because it is strong and grows quickly; it produces 250% more fiber than cotton and 600% more fiber than flax when grown on the same land. Hemp has been used to make paper. It was used to make canvas, and the word canvas derives from cannabis. Hemp was very popular as it had many uses. Abaca or Manila replaced its use for rope. Burlap, made from jute, took over the sacking market. The paper industry began using wood pulp. The carpet industry switched over to wool, sisal, and jute, then nylon. Netting and webbing applications were taken over by cotton and synthetics.

In Europe and China, hemp fibers have been used in prototype quantities to strengthen concrete, and in other composite materials for many construction and manufacturing applications.

Composite materials

A mixture of fiberglass, hemp fiber, kenaf, and flax has been used since 2002 to make composite panels for automobiles. The choice of which bast fiber to use is primarily based on cost and availability.

Paper

There is a niche market for hemp paper. World hemp paper pulp production was believed to be around 120,000 tons per year in 1991 which was about 0.05% of the world's annual pulp production volume. The cost of hemp pulp is approximately six times that of wood pulp, mostly due to the small size and outdated equipment of the few hemp processing plants in the Western world and hemp is harvested once a year (during August) and needs to be stored to feed the mill the whole year through. This storage requires a lot of (mostly manual) handling of the bulky stalk bundles, which accounts for a high raw material cost. Hemp pulp is bleached with hydrogen peroxide, which can also be used for wood pulp.

In 1916, US Department of Agriculture chief scientists Lyster H. Dewe, and Jason L. Merrill created paper made from hemp pulp, which they concluded was "favorable in comparison with those used with pulp wood."

The production of wood pulp paper still claims one of the highest carbon dioxide emissions by industry (second only to concrete production). The recovery boiler was invented in the early 1930s. The first recovery boilers were commissioned to wood-pulp mills during the mid-1930s, ECF (Elemental Chlorine Free), or TCF (Total chlorine Free) bleaching, better fiber filters etc. has created less of a demand for alternative raw materials. Hemp is currently of little significance as raw material for paper; however, it is scarcely grown in the developed world. The long-term price for pulpwood has been low compared with any alternative except recycled paper.

The decision of the United States Congress to pass the 1937 Marihuana Tax Act was based in part on testimony derived from articles in newspapers owned by William Randolph Hearst, who, some authors stress, had significant financial interests in the forest industry, which manufactured his newsprint.

The background material also included that from 1880 to 1933, the hemp grown in the United States had declined from 15,000 to 1,200 acres (4.9 km2), and that the price of line hemp had dropped from $12.50 per pound in 1914 to $9.00 per pound in 1933.  In 1935, however, hemp would also make a significant rebound. Hearst began a campaign against hemp, and published stories in his newspapers associating hemp with marijuana and attacking marijuana usage. As a result of the act, the production and use of hemp was discontinued.

Fabric

A modest hemp fabric industry exists. Recent developments in processing have made it possible to soften coarse fibers to a wearable level. Characteristics of hemp fiber are its superior strength and durability, resistance to ultraviolet light and mold, comfort and good absorbency (8%). The original Levi Strauss jeans were made from lightweight hemp canvas.

Cordage

Hemp rope is notorious for breaking due to rot as the capillary effect of the rope-woven fibers tended to hold liquid at the interior, while seeming dry from the outside. Hemp rope used in the age of sailing-ships was protected by tarring, a labor-intensive process (and source of the Jack Tar nickname for sailors). Hemp rope was phased out when Manila, which does not require tarring, became available. Manila is sometimes referred to as Manila hemp, but is not related to hemp; it is Abacá, a species of banana.

Water and soil purification

Hemp can be used as a "mop crop" to clear impurities out of wastewater, such as sewage effluent, excessive phosphorus from chicken litter, or other unwanted substances or chemicals. Eco-technologist Dr. Keith Bolton from Southern Cross University in Lismore, New South Wales, Australia, is a leading researcher in this area. Hemp is being used to clean contaminants at Chernobyl nuclear disaster site.

Weed control

Hemp, because of its height, dense foliage and its high planting density as a crop, is a very effective and long used method of killing tough weeds in farming (by minimizing the pool of weed seeds of the soil). Using hemp this way can help farmers avoid the use of herbicides, to help gain organic certification and to gain the benefits of crop rotation per se.

Fuel

Biofuels such as biodiesel and alcohol fuel can be made from the oils in hemp seeds and stalks, and the fermentation of the plant as a whole, respectively.

Henry Ford grew industrial hemp on his estate after 1937, possibly to prove the cheapness of methanol production at Iron Mountain. He made plastic cars (the so-called Hemp Car) with wheat straw, hemp and sisal. (Popular Mechanics, Dec. 1941, "Pinch Hitters for Defense.") Filtered hemp oil can be used directly to power diesels. In 1892, Rudolph Diesel invented the diesel engine, which he intended to fuel “by a variety of fuels, especially vegetable and seed oils.”

A herbicide is a substance used to kill unwanted plants. Selective herbicides kill specific targets while leaving the desired crop relatively unharmed. Some of these act by interfering with the growth of the weed and are often synthetic "imitations" of plant hormones. Herbicides used to clear waste ground, industrial sites, railways and railway embankments are non-selective and kill all plant material with which they come into contact. Smaller quantities are used in forestry, pasture systems, and management of areas set aside as wildlife habitat.

Some plants produce natural herbicides, such as the genus Juglans (walnuts), or the tree of heaven; the study of such natural herbicides, and other related chemical interactions, is called allelopathy.

Herbicides are widely used in agriculture and in landscape turf management. In the U.S., they account for about 70% of all agricultural pesticide use.

Herbicide use generally has negative impacts on bird populations, although the impacts are highly variable and often require field studies to predict accurately. Laboratory studies have at times overestimated negative impacts on birds due to toxicity, predicting serious problems that were not observed in the field. Most observed effects are due not to toxicity but to habitat changes and the decrease in abundance of species birds rely on for food or shelter. Herbicide use in sylviculture, used to favor certain types of growth following clearcutting, can cause significant drops in bird populations. Even when herbicides are used which have low toxicity to birds, the herbicides decrease the abundance of many types of vegetation which the birds rely on.

Herbicide use in agriculture in Britain has been linked to a decline in seed-eating bird species which rely on the weeds killed by the herbicides. Heavy use of herbicides in neotropical agricultural areas has been one of many factors implicated in limiting the usefulness of such agricultural land for wintering migratory birds.

Source: Wikipedia

A hybrid vehicle is a vehicle that uses two or more distinct power sources to move the vehicle. The term most commonly refers to hybrid electric vehicles (HEVs), which combine an internal combustion engine and one or more electric motors.

Power sources for hybrid vehicle include:
•    On-board or out-board rechargeable energy storage system (RESS)
•    Gasoline or Diesel fuel
•    Hydrogen
•    Compressed air
•    Liquid nitrogen
•    Human powered e.g. pedaling or rowing
•    Wind
•    Compressed or liquefied natural gas
•    Solar
•    Waste heat from internal combustion engine. This can be converted to steam or electricity (eg via Stirling engine or Thermogenerator) to increase vehicle propulsion. The extra power may also be used for supplemental systems (eg cooling for cool-trucks, ...)
•    Coal, wood, Biochar or other solid combustibles
•    Electromagnetic fields, Radio waves

When the term hybrid vehicle is used, it most often refers to a Hybrid electric vehicle. These encompass such vehicles as the AHS2 (Chevrolet Tahoe, GMC Yukon, Chevrolet Silverado, Cadillac Escalade, and the Saturn Vue), Toyota Prius, Toyota Camry Hybrid, Ford Escape Hybrid, Toyota Highlander Hybrid, Honda Insight, Honda Civic Hybrid and others. A petroleum-electric hybrid most commonly uses internal combustion engines (generally gasoline or Diesel engines, powered by a variety of fuels) and electric batteries to power electric motors. There are many types of petroleum-electric hybrid drivetrains, from Full hybrid to Mild hybrid, which offer varying advantages and disadvantages.

While liquid fuel/electric hybrids date back to the late 1800s, the braking regenerative hybrid was invented by David Arthurs, an electrical engineer from Springdale, Arkansas in 1978–79. His home-converted Opel GT was reported to get as much as 75MPG and plans are still sold to this original design, and the "Mother Earth News" modified version on their website.

The plug-in-electric-vehicle (PEV) is becoming more and more common. It has the range needed in locations where there are wide gaps with no services. The batteries can be plugged in to house (mains) electricity for charging, as well as being charged while the engine is running.

Source: Wikipedia

The potential energy accumulated in waterfalls can be transformed into electrical power. Hydroelectric centers take advantage of the energy of rivers to move turbines that move an electric generator.

This is one of the six greenhouse gases that the Kyoto Protocol is trying to eliminate. It is produced commercially as a substitute for chlorofluorocarbons. HFCs are used most in refrigeration and the manufacture of semi-conductors.

In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. With relation to chemical terminology, aromatic hydrocarbons or arenes, alkanes, alkenes and alkyne-based compounds composed entirely of carbon and hydrogen are referred to as "pure" hydrocarbons, whereas other hydrocarbons with bonded compounds or impurities of sulfur or nitrogen, are referred to as "impure", and remain somewhat erroneously referred to as hydrocarbons.

Hydrocarbons are referred to as consisting of a "backbone" or "skeleton" composed entirely of carbon and hydrogen and other bonded compounds, and have a functional group that generally facilitates combustion.

The majority of hydrocarbons found naturally occur in crude oil, where decomposed organic matter provides an abundance of carbon and hydrogen which, when bonded, can catenate to form seemingly limitless chains.

Source: Wikipedia

Transfer of materials, energy, or organisms through water in the elements of the hydrological cycle.

The water cycle, also known as the hydrologic cycle, describes the continuous movement of water on, above and below the surface of the Earth. Since the water cycle is truly a "cycle," there is no beginning or end. Water can change states among liquid, vapor, and ice at various places in the water cycle. Although the balance of water on Earth remains fairly constant over time, individual water molecules can come and go.

The sun, which drives the water cycle, heats water in the oceans. Water evaporates as vapor into the air. Ice and snow can sublimate directly into water vapor. Evapotranspiration is water transpired from plants and evaporated from the soil. Rising air currents take the vapor up into the atmosphere where cooler temperatures cause it to condense into clouds. Air currents move clouds around the globe, cloud particles collide, grow, and fall out of the sky as precipitation. Some precipitation falls as snow and can accumulate as ice caps and glaciers, which can store frozen water for thousands of years. Snowpacks can thaw and melt, and the melted water flows over land as snowmelt.

Most precipitation falls back into the oceans or onto land, where the precipitation flows over the ground as surface runoff. A portion of runoff enters rivers in valleys in the landscape, with stream flow moving water towards the oceans. Runoff and groundwater are stored as freshwater in lakes. Not all runoff flows into rivers. Much of it soaks into the ground as infiltration. Some water infiltrates deep into the ground and replenishes aquifers, which store huge amounts of freshwater for long periods of time. Some infiltration stays close to the land surface and can seep back into surface-water bodies (and the ocean) as groundwater discharge. Some groundwater finds openings in the land surface and comes out as freshwater springs. Over time, the water returns to the ocean, where our water cycle started.

Different Processes

• Precipitation
  Condensed water vapor that falls to the Earth's surface. Most precipitation occurs as rain, but also includes snow, hail, fog drip, graupel, and sleet. Approximately 505,000 km3 (121,000 cu mi) of water fall as precipitation each year, 398,000 km3 (95,000 cu mi) of it over the oceans.
• Canopy interception
  The precipitation that is intercepted by plant foliage and eventually evaporates back to the atmosphere rather than falling to the ground.
• Snowmelt
  The runoff produced by melting snow.
• Runoff
  The variety of ways by which water moves across the land. This includes both surface runoff and channel runoff. As it flows, the water may infiltrate into the ground, evaporate into the air, become stored in lakes or reservoirs, or be extracted for agricultural or other human uses.
• Infiltration
  The flow of water from the ground surface into the ground. Once infiltrated, the water becomes soil moisture or groundwater.
• Subsurface Flow
  The flow of water underground, in the vadose zone and aquifers. Subsurface water may return to the surface (e.g. as a spring or by being pumped) or eventually seep into the oceans. Water returns to the land surface at lower elevation than where it infiltrated, under the force of gravity or gravity induced pressures. Groundwater tends to move slowly, and is replenished slowly, so it can remain in aquifers for thousands of years.
• Evaporation
  The transformation of water from liquid to gas phases as it moves from the ground or bodies of water into the overlying atmosphere. The source of energy for evaporation is primarily solar radiation. Evaporation often implicitly includes transpiration from plants, though together they are specifically referred to as evapotranspiration. Total annual evapotranspiration amounts to approximately 505,000 km3 (121,000 cu mi) of water, 434,000 km3 (104,000 cu mi) of which evaporates from the oceans.
• Sublimation
  The state change directly from solid water (snow or ice) to water vapor.
• Advection
  The movement of water — in solid, liquid, or vapor states — through the atmosphere. Without advection, water that evaporated over the oceans could not precipitate over land.
• Condensation
  The transformation of water vapor to liquid water droplets in the air, producing clouds and fog.
• Transpiration
  The release of water vapor from plants into the air. Water vapor is a gas that cannot be seen.

Source: Wikipedia

The component of the climate system comprising liquid surface and subterranean water, such as oceans, seas, rivers, fresh water lakes, underground water, etc.

The IEA is a Paris-based energy forum established in 1974. It works with the Organization for Economic Cooperation and Development (OECD) to enhance different energy-related strategies, such as the application of joint measures to meet oil supply emergencies, the sharing of energy-related information, the coordination of energy policies, and the cooperation in the development of rational energy programs.

Jute is a long, soft, shiny vegetable fiber that can be spun into coarse, strong threads. It is produced from plants in the genus Corchorus, family Tiliaceae.

Jute is one of the cheapest natural fibers and is second only to cotton in amount produced and variety of uses. Jute fibers are composed primarily of the plant materials cellulose (major component of plant fiber) and lignin (major components wood fiber). It is thus a ligno-cellulosic fiber that is partially a textile fiber and partially wood. It falls into the bast fiber category (fiber collected from bast or skin of the plant) along with kenaf, industrial hemp, flax (linen), ramie, etc. The industrial term for jute fiber is raw jute. The fibers are off-white to brown, and 1–4 meters (3–12 feet) long.

Jute fiber is often called Hessian; jute fabrics are also called Hessian cloth and jute sacks are called gunny bags in some European countries. The fabric made from jute is popularly known as burlap in North America.

Jute is a rain-fed crop with little need for fertilizer or pesticides. The production is concentrated in India and Bangladesh. The jute fiber comes from the stem and ribbon (outer skin) of the jute plant. The fibers are first extracted by retting. The retting process consists of bundling jute stems together and immersing them in low, running water. There are two types of retting: stem and ribbon. After the retting process, stripping begins. Women and children usually do this job. In the stripping process, non-fibrous matter is scraped off, and then the workers dig in and grab the fibers from within the jute stem.

Jute is the second most important vegetable fiber after cotton; not only for cultivation, but also for various uses. Jute is used chiefly to make cloth for wrapping bales of raw cotton, and to make sacks and coarse cloth. The fibers are also woven into curtains, chair coverings, carpets, area rugs, Hessian cloth, and backing for linoleum.

While jute is being replaced by synthetic materials in many of these uses, some uses take advantage of jute's biodegradable nature, where synthetics would be unsuitable. Examples of such uses include containers for planting young trees which can be planted directly with the container without disturbing the roots, and land restoration where jute cloth prevents erosion occurring while natural vegetation becomes established.

The fibers are used alone or blended with other types of fibers to make twine and rope. Jute butts, the coarse ends of the plants, are used to make inexpensive cloth. Conversely, very fine threads of jute can be separated out and made into imitation silk. As jute fibers are also being used to make pulp and paper, and with increasing concern over forest destruction for the wood pulp used to make most paper, the importance of jute for this purpose may increase. Jute has a long history of use in the sackings, carpets, wrapping fabrics (cotton bale), and construction fabric manufacturing industry.

Source: Wikipedia

The Kyoto Protocol is a protocol to the United Nations Framework Convention on Climate Change (UNFCCC or FCCC), an international environmental treaty with the goal of achieving "stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system." The Kyoto Protocol establishes legally binding commitment for the reduction of four greenhouse gases (carbon dioxide, methane, nitrous oxide, sulphur hexafluoride), and two groups of gases (hydrofluorocarbons and perfluorocarbons) produced by "annex I" (industrialized) nations, as well as general commitments for all member countries. As of January 2009, 183 parties have ratified the protocol, which was initially adopted for use on 11 December 1997 in Kyoto, Japan and which entered into force on 16 February 2005.

Under the Kyoto Protocol, industrialized countries agreed to reduce their collective green house gas (GHG) emissions by 5.2% from the level in 1990. National limitations range from the reduction of 8% for the European Union and others to 7% for the United States, 6% for Japan, and 0% for Russia. The treaty permitted the emission increases of 8% for Australia and 10% for Iceland.

Kyoto includes defined "flexible mechanisms" such as Emissions Trading, the Clean Development Mechanism and Joint Implementation to allow annex I economies to meet their GHG emission limitations by purchasing GHG emission reductions credits from elsewhere, through financial exchanges, projects that reduce emissions in non-annex I economies, from other annex I countries, or from annex I countries with excess allowances. In practice this means that non-annex I economies have no GHG emission restrictions, but have financial incentives to develop GHG emission reduction projects to receive "carbon credits" that can then be sold to annex I buyers, encouraging sustainable development. In addition, the flexible mechanisms allow annex I nations with efficient, low GHG-emitting industries, and high prevailing environmental standards to purchase carbon credits on the world market instead of reducing greenhouse gas emissions domestically. Annex I entities typically will want to acquire carbon credits as cheaply as possible, while non-annex I entities want to maximize the value of carbon credits generated from their domestic Greenhouse Gas Projects.

Among the annex I signatories, all nations have established Designated National Authorities to manage their greenhouse gas portfolios; countries including Japan, Canada, Italy, the Netherlands, Germany, France, Spain and others are actively promoting government carbon funds, supporting multilateral carbon funds intent on purchasing carbon credits from non-annex I countries, and are working closely with their major utility, energy, oil and gas and chemicals conglomerates to acquire greenhouse gas certificates as cheaply as possible. Virtually all of the non-annex I countries have also established Designated National Authorities to manage the Kyoto process, specifically the "CDM process" that determines which GHG Projects they wish to propose for accreditation by the CDM Executive Board.

Methane is a chemical compound with the chemical formula CH4. It is the simplest alkane, and the main component of natural gas. Methane's bond angles are 109.5 degrees. Burning methane in the presence of oxygen produces carbon dioxide and water. The relative abundance of methane and its clean burning process makes it an attractive fuel. However, because it is a gas at normal temperature and pressure, methane is difficult to transport from its source. In its natural gas form, it is generally transported in bulk by pipeline or LNG carriers; few countries transport it by truck.

Methane is a relatively potent greenhouse gas with a high global warming potential of 72 (averaged over 20 years) or 25 (averaged over 100 years). Methane in the atmosphere is eventually oxidized, producing carbon dioxide and water. As a result, methane in the atmosphere has a half life of seven years.

The abundance of methane in the Earth's atmosphere in 1998 was 1745 parts per billion, up from 700 ppb in 1750. Methane can trap about 20 times the heat of CO2. In the same time period, CO2 increased from 278 to 365 parts per million. The radiative forcing effect due to this increase in methane abundance is about one-third of that of the CO2 increase. In addition, there is a large, but unknown, amount of methane in methane clathrates in the ocean floors. The Earth's crust contains huge amounts of methane. Large amounts of methane are produced anaerobically by methanogenesis. Other sources include mud volcanoes, which are connected with deep geological faults, and livestock (primarily cows) from enteric fermentation.

Source: Wikipedia

Non-renewable energy is energy taken from finite resources that will eventually dwindle, becoming too expensive or too environmentally damaging to retrieve, as opposed to renewable energy sources, which are naturally replenished in a relatively short period of time.

Non-renewable energy sources include:
1-fossil fuels (coal, petroleum, natural gas)
2-nuclear energy (uranium)

Natural resources such as coal, petroleum, oil and natural gas take thousands of years to form naturally and cannot be replaced as fast as they are being consumed. Eventually natural resources will become too costly to harvest and humanity will need to find other sources of energy. At present, the main energy sources used by humans are non-renewable as they are cheap to produce.

Nuclear fission is the decomposition of certain stable or unstable atomic nuclei when they are bombarded with neutrons. Gaining a neutron causes the formation of a new, unstable isotope that spontaneously divides into two or more atoms, emitting two or three neutrons that crash into other nuclei, causing a chain reaction. The sum of the masses of these last obtained atoms plus the detached neutrons is less than the mass of the original atom, which verifies Albert Einstein’s formula E=mc², which releases energy.

Nuclear fusion is the process by which multiple like-charged atomic nuclei join together to form a heavier nucleus. It is accompanied by the release or absorption of energy, which allows matter to enter a plasma state.

Nuclear fusion occurs naturally in stars. Artificial fusion in human enterprises has also been achieved, although it has not yet been completely controlled. Building upon the nuclear transmutation experiments of Ernest Rutherford done a few years earlier, fusion of light nuclei (hydrogen isotopes) was first observed by Mark Oliphant in 1932; the steps of the main cycle of nuclear fusion in stars were subsequently worked out by Hans Bethe throughout the remainder of that decade. Research into fusion for military purposes began in the early 1940s as part of the Manhattan Project, but was not successful until 1952. Research into controlled fusion for civilian purposes began in the 1950s, and continues to this day.

Source: Wikipedia

This term can refer to different topics, but usually refers to a method of cultivation. Crops that are grown organically, meaning without the use of pesticides, chemical fertilizers, antibiotics, growth hormones, or food additives.

Organic foods are made according to certain production standards. For the vast majority of human history, agriculture can be described as organic; only during the 20th century was a large supply of new synthetic chemicals introduced to the food supply. This more recent style of production is referred to as "conventional," though organic production has been the convention for a much greater period of time. Under organic production, the use of conventional non-organic pesticides, insecticides and herbicides is greatly restricted and saved as a last resort. However, contrary to popular belief, certain non-organic fertilizers are still used. If livestock are involved, they must be reared without the routine use of antibiotics and without the use of growth hormones, and generally fed a healthy diet.

According to the definition of “organic,” all herbicides, except for arsenic, are organic. However, there are many herbicides that are made from natural ingredients that are considered compatible with ecological agriculture. These include spices, citrus oils, vinegar, and steam.

Ozone or trioxygen (O3) is a simple triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic O2. Ground-level ozone is an air pollutant with harmful effects on the respiratory systems of animals. The ozone layer in the upper atmosphere filters potentially damaging ultraviolet light from reaching the Earth's surface. It is present in low concentrations throughout the Earth's atmosphere. It has many industrial and consumer applications.

Source: Wikipedia

The ozone layer is a layer in Earth's atmosphere which contains relatively high concentrations of ozone (O3). This layer absorbs 93-99% of the sun's high frequency ultraviolet light, which is potentially damaging to life on Earth. Over 91% of the ozone in Earth's atmosphere is present in the stratosphere. It is mainly located in the lower portion of the stratosphere from approximately 10 km to 50 km above Earth, though its thickness varies seasonally and geographically.

Ozone in the Earth's stratosphere is created by ultraviolet light striking oxygen molecules containing two oxygen atoms (O2), splitting them into individual oxygen atoms (atomic oxygen); the atomic oxygen then combines with unbroken O2 to create ozone, O3. The ozone molecule is also unstable (although, in the stratosphere, long-lived) and when ultraviolet light hits ozone it splits into a molecule of O2 and an atom of atomic oxygen, a continuing process called the ozone-oxygen cycle, thus creating an ozone layer in the stratosphere, the region from about 10 to 50 km (32,000 to 164,000 feet) above Earth's surface. Ozone concentrations are greatest between about 20 and 40 km, where they range from about 2 to 8 parts per million. If all of the ozone were compressed to the pressure of the air at sea level, it would be only a few millimeters thick.

Although the concentration of the ozone in the ozone layer is very small, it is vitally important to life because it absorbs biologically harmful ultraviolet (UV) radiation emitted from the Sun. UV radiation is divided into three categories, based on its wavelength; these are referred to as UV-A (400-315 nm), UV-B (315-280 nm), and UV-C (280-100 nm). UV-C, which would be very harmful to humans, is entirely screened out by ozone at around 35 km of altitude. UV-B radiation can be harmful to the skin and is the main cause of sunburn; excessive exposure can also cause genetic damage, resulting in problems such as skin cancer. The ozone layer is very effective at screening out UV-B; for radiation with a wavelength of 290 nm, the intensity at Earth's surface is 350 billion times weaker than at the top of the atmosphere. Nevertheless, some UV-B reaches the surface. Most UV-A reaches the surface; this radiation is significantly less harmful, although it can potentially cause genetic damage.

The ozone layer can be depleted by free radical catalysts, including nitric oxide (NO), nitrous oxide (N2O), hydroxyl (OH), atomic chlorine (Cl), and atomic bromine (Br). While there are natural sources for all of these species, the concentrations of chlorine and bromine have increased markedly in recent years due to the release of large quantities of manmade organohalogen compounds, especially chlorofluorocarbons (CFCs) and bromofluorocarbons. These highly stable compounds are capable of surviving the rise to the stratosphere, where Cl and Br radicals are liberated by the action of ultraviolet light. Each radical is then free to initiate and catalyze a chain reaction capable of breaking down over 100,000 ozone molecules. The breakdown of ozone in the stratosphere results in the ozone molecules being unable to absorb ultraviolet radiation. Consequently, unabsorbed and dangerous ultraviolet-B radiation is able to reach the Earth’s surface. Ozone levels, over the northern hemisphere, have been dropping by 4% per decade. Over approximately 5% of the Earth's surface, around the north and south poles, much larger (but seasonal) declines have been seen; these are the ozone holes.

In 2009, nitrous oxide (N2O) was the largest ozone-depleting substance emitted through human activities.

In 1978, the United States, Canada and Norway, enacted bans on CFC-containing aerosol sprays that are thought to damage the ozone layer. The European Community rejected an analogous proposal to do the same. In the U.S., chlorofluorocarbons continued to be used in other applications, such as refrigeration and industrial cleaning, until the discovery of the Antarctic ozone hole in 1985. After negotiation of an international treaty (the Montreal Protocol), CFC production was sharply limited beginning in 1987 and phased out completely by 1996.

On August 2, 2003, scientists announced that the depletion of the ozone layer may be slowing down due to the international ban on CFCs. Three satellites and three ground stations confirmed that the upper atmosphere ozone depletion rate has slowed down significantly during the past decade. The study was organized by the American Geophysical Union. Some breakdown can be expected to continue due to CFCs used by nations which have not banned them, and due to gases which are already in the stratosphere. CFCs have very long atmospheric lifetimes, ranging from 50 to over 100 years, so the final recovery of the ozone layer is expected to require several lifetimes.

Compounds containing C–H bonds have been designed to replace the function of CFC's (such as HCFC), since these compounds are more reactive and less likely to survive long enough in the atmosphere to reach the stratosphere where they could affect the ozone layer. However, while being less damaging than CFC's, HCFC's also have a significant negative impact on the ozone layer. HCFC's are therefore also being phased out.

Source: Wikipedia

A pesticide is a substance or mixture of substances used to kill a pest. A pesticide is any substance or mixture of substance intended for: - preventing, destroying, repelling or mitigating any pest. A pesticide may be a chemical substance, biological agent (such as a virus or bacteria), antimicrobial, disinfectant or device used against any pest. Pests include insects, plant pathogens, weeds, mollusks, birds, mammals, fish, nematodes (roundworms), microbes and people that destroy property, spread or are a vector for disease or cause a nuisance. Although there are benefits to the use of pesticides, there are also drawbacks, such as potential toxicity to humans and other animals. FAO has defined the term of pesticide as:

any substance or mixture of substances intended for preventing, destroying or controlling any pest, including vectors of human or animal disease, unwanted species of plants or animals causing harm during or otherwise interfering with the production, processing, storage, transport or marketing of food, agricultural commodities, wood and wood products or animal feedstuffs, or substances which may be administered to animals for the control of insects, arachnids or other pests in or on their bodies. The term includes substances intended for use as a plant growth regulator, defoliant, desiccant or agent for thinning fruit or preventing the premature fall of fruit, and substances applied to crops either before or after harvest to protect the commodity from deterioration during storage and transport.

Source: Wikipedia

Polyethylene terephthalate (sometimes written poly(ethylene terephthalate)), commonly abbreviated PET, PETE, or the obsolete PETP or PET-P), is a thermoplastic polymer resin of the polyester family and is used in synthetic fibers; beverage, food and other liquid containers; thermoforming applications; and engineering resins often in combination with glass fiber.

PET can be semi-rigid to rigid, depending on its thickness, and is very lightweight. It makes a good gas and fair moisture barrier, as well as a good barrier to alcohol (requires additional "Barrier" treatment) and solvents. It is strong and impact-resistant. It is naturally colorless with high transparency.

PET bottles are excellent barrier materials and are widely used for soft drinks. For certain specialty bottles, PET sandwiches an additional polyvinyl alcohol to further reduce its oxygen permeability.

When produced as a thin film (biaxially oriented PET film, often known by one of its tradenames, "Mylar"), PET can be aluminized by evaporating a thin film of metal onto it to reduce its permeability, and to make it reflective and opaque (MPET). These properties are useful in many applications, including flexible food packaging and thermal insulation, such as "space blankets". Because of its high mechanical strength, PET film is often used in tape applications, such as the carrier for magnetic tape or backing for pressure sensitive adhesive tapes.

Non-oriented PET sheet can be thermoformed to make packaging trays and blisters. If crystallizable PET is used, the trays can be used for frozen dinners, since they withstand both freezing and oven baking temperatures.

When filled with glass particles or fibers, it becomes significantly stiffer and more durable. This glass-filled plastic, in a semi-crystalline formulation, is sold under the tradename Rynite, Arnite, Hostadur, and Crastin.

While most thermoplastics can, in principle, be recycled, PET bottle recycling is more practical than many other plastic applications. The primary reason is that plastic carbonated soft drink bottles and water bottles are almost exclusively PET, which makes them more easily identifiable in a recycle stream. PET has a resin identification code of 1. One of the uses for a recycled PET bottle is for the manufacture of polar fleece material. Among its many uses, companies, such as English Retreads use the PET material to line their products. It can also make fiber for polyester products.

Because of the recyclability of PET and the relative abundance of post-consumer waste in the form of bottles, PET is rapidly gaining market share as a carpet fiber. Leading the way, Mohawk Industries released everSTRAND in 1999, a 100% post-consumer recycled content PET fiber. Since that time, more than 17 billion bottles have been recycled into carpet fiber. Pharr Yarns, a supplier to numerous carpet manufacturers including Looptex, Dobbs Mills, and Berkshire Flooring, produces a BCF (bulk continuous filament) PET carpet fiber containing a minimum of 25% post-consumer recycled content.

Source: Wikipedia

The photoelectric effect is a phenomenon in which electrons are emitted from matter (metals and non-metallic solids, liquids, or gases) after the absorption of energy from electromagnetic radiation such as X-rays or visible light. The emitted electrons can be referred to as photoelectrons in this context. The effect is also called the Hertz Effect, because it was discovered by Heinrich Rudolf Hertz, although the term has generally fallen out of use. Hertz observed and then showed that electrodes illuminated with ultraviolet light create electric sparks more easily.

Source: Wikipedia

Photosynthesis is the process by which green plants, algae and some bacteria take carbon dioxide from the air (or bicarbonate in water) to build carbohydrates. There are several pathways of photosynthesis with different responses to atmospheric carbon dioxide concentrations.

Photovoltaics (or PV) is the field of technology and research related to the application of solar cells for energy by converting solar energy (sunlight, including ultra violet radiation) directly into electricity (solar electricity). Due to the growing demand for renewable sources of energy, the manufacture of solar cells and photovoltaic arrays has advanced dramatically in recent years. One of these new advancements is a newer-thin film. Although it is not as efficient as the old one, it is lighter, cheaper, and can be made more transparent. It is expected to start a new chapter in the story of solar power.

Photovoltaic production has been doubling every 2 years, increasing by an average of 48 percent each year since 2002, making it the world’s fastest-growing energy technology, and then increased by 110% in 2008. At the end of 2008, the cumulative global PV installations reached 15,200 megawatts. Roughly 90% of this generating capacity consists of grid-tied electrical systems. Such installations may be ground-mounted (and sometimes integrated with farming and grazing) or built into the roof or walls of a building, known as Building Integrated Photovoltaics or BIPV for short.

Net metering and financial incentives, such as preferential feed-in tariffs for solar-generated electricity have supported solar PV installations in many countries.

Source: Wikipedia

A photovoltaic cell is a type of photoelectric cell that uses the photovoltaic effect to generate electrical energy using the potential difference that arises between materials when the surface of the cell is exposed to electromagnetic radiation.

A photovoltaic cell is commonly used for detecting radiation (for example infrared detectors) or measurement of light intensity (for example in measuring optical density) and chemical processes (for example Spectrophotometry) and for conversion of light energy to electricity in solar cells.

The photovoltaic cell was developed in 1954 at the Bell Laboratories and is used extensively in the space program. Photovoltaic cells convert sunlight into direct current and are about 30% efficient. The average lifespan of a photovoltaic cell is 25-30 years and while the cost of initially purchasing and setting up the cells is high, there are many advantages to this renewable energy source. Sunlight is inexhaustible, free and environmentally “clean.”

Solar energy can be very effective in powering e.g. “small remote villages” with limited access to more common energy resources with a wider distribution network, but more detrimental environmental effects, like fossil fuels.

Another important distinction to be made, in terms of the process of obtaining electrical energy from photovoltaic cells, is that between the photovoltaic principle of generating electricity and the photoelectric effect. While in the photoelectric effect electrons are ‘ejected’ from the metal, in the photovoltaic phenomenon electrons make a transition from a lower to a higher energy state having absorbed photons of the right energy.

Source: Wikipedia

Primary energy, also referred to as energy sources, is the energy embodied in natural resources (e.g., coal, crude oil, natural gas, uranium) that has not undergone any anthropogenic conversion. This primary energy needs to be converted and transported to become usable energy (e.g., light).

Pollutants that come directly from their emission sources.

Recycling involves processing used materials into new products to prevent waste of potentially useful materials, reduce the consumption of fresh raw materials, reduce energy usage, reduce air pollution (from incineration) and water pollution (from landfilling) by reducing the need for "conventional" waste disposal, and lower greenhouse gas emissions as compared to virgin production. Recycling is a key component of modern waste management and is the third component of the "Reduce, Reuse, Recycle" waste hierarchy.

Recyclable materials include many kinds of glass, paper, metal, plastic, textiles, and electronics. Although similar in effect, the composting or other reuse of biodegradable waste – such as food or garden waste – is not typically considered recycling. Materials to be recycled are either brought to a collection center or picked up from the curbside, then sorted, cleaned, and reprocessed into new materials bound for manufacturing.

In a strict sense, recycling of a material would produce a fresh supply of the same material, for example used office paper to more office paper, or used foamed polystyrene to more polystyrene. However, this is often difficult or too expensive (compared with producing the same product from raw materials or other sources), so "recycling" of many products or materials involves their reuse in producing different materials (e.g., cardboard) instead. Another form of recycling is the salvage of certain materials from complex products, either due to their intrinsic value (e.g., lead from car batteries, or gold from computer components), or due to their hazardous nature (e.g., removal and reuse of mercury from various items).

This type of activity is a fundamental step in the sustainability of the environment.

Source: Wikipedia

Renewable energy, also known as alternative energy, is energy generated from natural resources—such as sunlight, wind, rain, tides, and geothermal heat—which are renewable (naturally replenished). In 2006, about 18% of global final energy consumption came from renewables, with 13% coming from traditional biomass, such as wood-burning. Hydroelectricity was the next largest renewable source, providing 3% of global energy consumption and 15% of global electricity generation.

Wind power is growing at the rate of 30 percent annually, with a worldwide installed capacity of 121,000 megawatts (MW) in 2008, and is widely used in European countries and the United States. The annual manufacturing output of the photovoltaics industry reached 6,900 MW in 2008, and photovoltaic (PV) power stations are popular in Germany and Spain. Solar thermal power stations operate in the USA and Spain, and the largest of these is the 354 MW SEGS power plant in the Mojave Desert. The world's largest geothermal power installation is The Geysers in California, with a rated capacity of 750 MW. Brazil has one of the largest renewable energy programs in the world, involving production of ethanol fuel from sugar cane, and ethanol now provides 18 percent of the country's automotive fuel. Ethanol fuel is also widely available in the USA.

While most renewable energy projects and production are large-scale, renewable technologies are also suited to small off-grid applications, sometimes in rural and remote areas, where energy is often crucial in human development. Kenya has the world's highest household solar ownership rate with roughly 30,000 small (20–100 watt) solar power systems sold per year.

Renewable energy sources can be divided into two categories: those that do not cause pollution, or “clean” sources, and those that do cause pollution.

Some examples from the first category:
1- Sun: solar power.
2- Wind: eolic power.
3- Rivers and fresh water currents: hydraulic power.
4- Seas and oceans: tidal power.
5- The heat of the Earth: geothermal power.
6- Waves: wave power.
7- The movement of masses of freshwater to masses of saltwater: blue energy.

Clean sources of renewable energy do not produce greenhouse gasses or other emissions.

The substitution of renewable energy sources for fossil fuels will make for a cleaner atmosphere, a reduction of greenhouse gas emissions, and a sustainable future.

Source: Wikipedia

Renewable is a term used to refer to resources. A natural resource is renewable if it is replaced naturally at a rate comparable to or faster than the rate that it is consumed by human beings or other users. Other resources that are not only renewable, but are also perpetual are resources such as solar radiation, tides, wind, and hydroelectric power. These are not in danger of being used up in the long term. Basic products such as leather, paper, and wood can be considered renewable.

Secondary pollutants are pollutants that originate from chemical interaction between primary pollutants and the components of the atmosphere. Examples of these include photochemical oxidants and some radicals such as ozone.

Solar power is the result of converting sunlight into electricity. Sunlight can be converted directly into electricity using photovoltaics (PV), or indirectly with concentrating solar power (CSP), which normally focuses the sun's energy to boil water which is then used to provide power. The largest solar power plants, like the 354 MW SEGS, are concentrating solar thermal plants, but recently multi-megawatt photovoltaic plants have been built. Completed in 2008, the 46 MW Moura photovoltaic power station in Portugal and the 40 MW Waldpolenz Solar Park in Germany are characteristic of the trend toward larger photovoltaic power stations. Much larger ones are proposed, such as the 550 MW Topaz Solar Farm, and the 600 MW Rancho Cielo Solar Farm.

Solar power is a predictably intermittent energy source, meaning that whilst solar power is not available at all times, we can predict with a very good degree of accuracy when it will and will not be available. Some technologies, such as solar thermal concentrators have an element of thermal storage, such as molten salts. These store spare solar energy in the form of heat which is made available overnight or during periods in which solar power is not available to produce electricity.

Photovoltaics were initially used to power small and medium-sized applications, from the calculator powered by a single solar cell to off-grid homes powered by a photovoltaic array.

Solar power plants can face high installation costs, although this has been decreasing due to the learning curve. Developing countries have started to build solar power plants, replacing other sources of energy generation.

Since solar radiation is intermittent, solar power generation is usually combined either with storage or other energy sources to provide continuous power, although for small distributed producer/consumers, net metering makes this transparent to the consumer. On a slightly larger scale, in Germany, a combined power plant has been demonstrated, using a mix of wind, biomass, hydro-, and solar power generation, resulting in 100% renewable energy.

Source: Wikipedia

Standby power, also called vampire power, vampire draw, phantom load, or leaking electricity, refers to the electric power consumed by electronic appliances while they are switched off or in a standby mode. A very common "electricity vampire" is a power adapter which has no power-off switch. Some such devices offer remote controls and digital clock features to the user, while other devices, such as power adapters for laptop computers and other electronic devices, consume power without offering any features.

The wasted standby power of individual household electronic devices is typically very small, but the sum of all such devices within the household becomes significant. Standby power makes up a portion of homes' miscellaneous electric load, which also includes small appliances, security systems, and other small power draws.

Standby power can be as high as 10 to 15 watts per device, and occasionally more. A 2005 study estimates the number of standby appliances in the EU at 3.7 billion. Although the power needed for functions like displays, indicators, and remote control functions is relatively small, the fact that the devices are continuously plugged in, and the number of such devices in the average household means that the energy usage can reach up to 22 percent of all appliance consumption, and around 10 percent of total residential consumption.

Source: Wikipedia

Sustainability has many definitions, but the most commonly used definition comes from the World Commission on Environment and Development, which is: the satisfaction of the needs of the present without compromising the ability of future generations to satisfy their own needs.

This means that sustainability refers to the balance of a species with the resources in its environment. It involves looking to the future and imagining the impact that a decision or action taken in the present will have on the future. The concept of sustainability is applied in different spheres, including construction and development, production, means of subsistence, and environmental impact.

More and more people are starting to measure their decisions and actions in terms of sustainability. Non-renewable resources can be used without the danger of them running out, so currently new methods are being developed, not just for us, but for our children as well.

The term sustainable development applies to socio-economic development and was first formalized in the document known as the Brundtland Report in 1987.

Sustainable society

A sustainable society is one that maintains and develops with the same amount of resources. Sustainability is possible where politics, economics, health, and leisure all work in harmony with the environment.

Sustainable architecture, also known as Green Architecture, Eco-architecture, or Environmentally Conscious Architecture, is a general term that describes environmentally-conscious design techniques in the field of architecture. Sustainable architecture is framed by the larger discussion of sustainability and the pressing economic and political issues of our world.

In the broad context, sustainable architecture seeks to minimize the negative environmental impact of buildings by enhancing efficiency and moderation in the use of materials, energy, and development space. Most simply, the idea of sustainability, or ecological design, is to ensure that our actions and decisions today do not inhibit the opportunities of future generations. This term can be used to describe an energy and ecologically conscious approach to the design of the built environment.

Sustainable energy

Energy efficiency over the entire life cycle of a building is the most important single goal of sustainable architecture. Architects use many different techniques to reduce the energy needs of buildings and increase their ability to capture or generate their own energy.

Heating, Ventilation and Cooling System Efficiency

The most important and cost effective element of an efficient heating, ventilating, and air conditioning (HVAC) system is a well insulated building. A more efficient building requires less heat generating or dissipating power, but may require more ventilation capacity to expel polluted indoor air.

Significant amounts of energy are flushed out of buildings in the water, air and compost streams. Off the shelf, on-site energy recycling technologies can effectively recapture energy from waste hot water and stale air and transfer that energy into incoming fresh cold water or fresh air.

Site and building orientation have some major effects on a building's HVAC efficiency.

Passive solar building design allows buildings to harness the energy of the sun efficiently, without the use of any active solar mechanisms such as photovoltaic cells or solar hot water panels. Typically passive solar building designs incorporate materials with high thermal mass that retain heat effectively, and strong insulation that works to prevent heat escape. Low energy designs also require the use of (mobile) solar shading, by means of awnings, blinds or shutters, to relieve the solar heat gain in summer and to reduce the need for artificial cooling.

In addition, low energy buildings typically have a very low surface area to volume ratio to minimize heat loss. This means that sprawling multi-winged building designs (often thought to look more "organic") are often avoided in favor of more centralized structures. Traditional cold climate buildings such as American colonial saltbox designs provide a good historical model for centralized heat efficiency in a small scale building.

Windows are placed to maximize the input of heat-creating light, while minimizing the loss of heat through glass, a poor insulator. In the northern hemisphere this usually involves installing a large number of south-facing windows to collect direct sun and severely restricting the number of north-facing windows. Certain window types, such as double or triple glazed insulated windows with gas filled spaces and low emissivity (low-E) coatings, provide much better insulation than single-pane glass windows.

Preventing excess solar gain by means of solar shading devices in the summer months is important to reduce cooling needs. Deciduous trees are often planted in front of windows to block excessive sun in summer with their leaves, but allow light through in winter when their leaves fall off. Louvers or light shelves are installed to allow the sunlight in during the winter (when the sun is lower in the sky), and keep it out in the summer (when the sun is high in the sky). Coniferous or evergreen plants are often planted to the north of buildings to shield against cold north winds.

In colder climates, heating systems are a primary focus for sustainable architecture, because they are typically one of the largest single energy drains in buildings.

In warmer climates, where cooling is a primary concern, passive solar designs can also be very effective. Masonry building materials with high thermal mass are very valuable for retaining the cool temperatures of night throughout the day. In addition, builders often opt for sprawling single story structures in order to maximize surface area and heat loss. Buildings are often designed to capture and channel existing winds, especially the cool winds coming from nearby bodies of water. Many of these valuable strategies are employed in some way by the traditional architecture of warm regions, such as south-western mission buildings.

In climates with four seasons, an integrated energy system will increase efficiency: when the building is well insulated, when it is sited to work with the forces of nature, when heat is recaptured (to be used immediately or stored), when the heat plant relying on fossil fuels or electricity is greater than 100% efficient, and when renewable energy is utilized.

Alternative energy production

Solar Panels

Active solar devices such as photovoltaic solar panels help to provide sustainable electricity for any use. Roofs are often angled toward the sun to allow photovoltaic panels to collect at maximum efficiency, and some buildings even move throughout the day to follow the sun. The Samundra Institute of Maritime Studies (SIMS) at Lonavala, near Pune India, has the longest photovoltaic wall in the world, at over ninety meters long.

Wind Turbines

Undersized wind turbines (normal turbines are often over 250 feet) may have been oversold and do not always provide the returns promised, particularly for North American households. The use of undersized wind turbines in energy production in sustainable structures requires the consideration of many factors.

In considering costs, small wind systems are generally more expensive than larger wind turbines relative to the amount of energy they produce. For small wind turbines, maintenance costs can be a deciding factor at sites with marginal wind-harnessing capabilities. At low-wind sites, maintenance can consume much of a small wind turbine’s revenue.

Wind turbines begin operating when winds reach 8 mph, achieve energy production capacity at speeds of 32-37 mph, and shut off to avoid damage at speeds exceeding 55 mph. The energy potential of a wind turbine is proportional to the square of the length of its blades and to the cube of the speed at which its blades spin. Though wind turbines are available that can supplement power for a single building, because of these factors, the efficiency of the wind turbine depends much upon the wind conditions at the building site. For these reasons, for wind turbines to be at all efficient, they must be installed at locations that are known to receive a constant amount of wind (with average wind speeds of more than 15mph), rather than locations that receive wind sporadically.

A small wind turbine can be installed on a roof. Installation issues then include the strength of the roof, vibration, and the turbulence caused by the roof ledge. Small-scale rooftop wind turbines have been known to be able to generate power from 10% to up to 25% of the electricity required of a regular domestic household dwelling. Turbines for residential scale use are available. They are usually approximately 7 feet (2 m) to 25 feet (8 m) in diameter and produce electricity at a rate of 900 watts to 10,000 watts at their tested wind speed. In the United States, residential wind turbines with outputs of 2-10 kW, typically cost between $12,000 and $55,000 installed ($6 per watt), although there are incentives and rebates available in 19 states that can reduce the purchase price for homeowners by up to 50 percent ($3 per watt).

Solar Water Heating

Solar water heaters—also called solar domestic hot water systems—can be a cost-effective way to generate hot water for your home. They can be used in any climate, and the fuel they use—sunshine—is free. Solar water heating systems consist of storage tanks and solar energy collectors, which are then used to heat up the water. There are also two types of systems: direct circulation systems and indirect circulation systems. Passive solar water heating systems are typically less expensive than active systems, but they're usually not as efficient. However, passive systems can be more reliable and may last longer.

Heat pumps

Ground source heat pumps are an efficient means of heating or cooling a building. They are not a renewable energy system or source of energy.

Convective heat transfer

Convective heat transfer can be beneficial or detrimental. Uncontrolled air infiltration from poor weatherization / weather-stripping / draught-proofing can contribute up to 40% of heat loss during winter, however strategic placement of operable windows or vents can enhance convection, cross-ventilation, and summer cooling when the outside air is of a comfortable temperature and relative humidity. Filtered energy recovery ventilation systems may be useful to eliminate undesirable humidity, dust, pollen, and microorganisms in unfiltered ventilation air.

Natural convection causing warm air to rise and cool air to fall can result in an uneven stratification of heat. This may cause uncomfortable variations in temperature in the upper and lower conditioned space, serve as a method of venting hot air, or be designed as a natural-convection air-flow loop for passive solar heat distribution and temperature equalization.

Natural human cooling by perspiration and evaporation may be facilitated through natural or forced convective air movement by fans, but ceiling fans can disturb the stratified insulating air layers at the top of a room, and accelerate heat transfer from a hot attic, or through nearby windows. In addition, high relative humidity inhibits evaporative cooling by humans.

Radiative heat transfer

The main source of heat transfer is radiant energy, and the sun is the primary source of radiant energy. Solar radiation occurs predominantly through the roof and windows (but also through walls). Thermal radiation moves from a warmer surface to a cooler one. Roofs receive the majority of the solar radiation delivered to a house. A cool roof, or green roof, in addition to a radiant barrier, can help prevent your attic from becoming hotter than the peak summer outdoor air temperature.

Windows are a ready and predictable site for thermal radiation. Energy from radiation can move into a window in the daytime and out of the same window at night. Radiation uses photons to transmit electromagnetic waves through a vacuum, or translucent medium. Solar heat gain can be significant even on cold clear days. Solar heat gain through windows can be reduced by insulated glazing, shading, and orientation. Windows are particularly difficult to insulate compared to roof and walls. Convective heat transfer through and around window coverings also degrade its insulation properties. When shading windows, external shading is more effective at reducing heat gain than internal window coverings.

The sun, when shining from the east or west, can provide warmth and lighting, but it can also overheat in summer if not shaded. In contrast, the low midday sun readily admits light and warmth during the winter, but can be easily shaded with appropriate length overhangs or angled louvres during summer. The amount of radiant heat received is related to the location latitude, altitude, cloud cover, and seasonal / hourly angle of incidence.

Another passive solar design principle is that thermal energy can be stored in certain building materials and released again when heat gain eases to stabilize diurnal (day/night) temperature variations.

The complex interaction of thermodynamic principles can be counterintuitive for first-time designers. Precise computer modeling can help avoid costly construction experiments.

Site specific considerations during design
•    Latitude and sun path
•    Seasonal variations in solar gain e.g. cooling or heating degree days, solar insulation, humidity
•    Diurnal variations in temperature
•    Micro-climate details related to breezes, humidity, vegetation and land contour
•    Obstructions / Over-shadowing - to solar gain or local cross-winds

Design elements for residential buildings in temperate climates
•    Placement of room-types, internal doors & walls, & equipment in the house.
•    Orienting the building to face the equator (or a few degrees to the East to capture the morning sun)
•    Extending the building dimension along the east/west axis
•    Adequately-sizing windows that face the midday sun in the winter, and are shaded in the summer.
•    Minimizing windows on other sides, especially western windows
•    Erecting correctly-sized, latitude-specific overhangs, or shading elements (shrubbery, trees, trellises, fences, shutters, etc.)
•    Using the appropriate amount and type of insulation including radiant barriers and bulk insulation to minimize seasonal excessive heat gain or loss
•    Using thermal mass to store excess solar energy during the winter day (which is then re-radiated during the night)

The precise amount of equator-facing glass and thermal mass should be based on careful consideration of latitude, altitude, climatic conditions, and heating/cooling degree day requirements.

Factors that can degrade thermal performance:
•    Deviation from ideal orientation and north/south/east/west aspect ratio
•    Excessive glass area ('over-glazing') resulting in overheating (also resulting in glare and fading of soft furnishings) and heat loss when ambient air temperatures fall
•    Installing glazing where solar gain during the day and thermal losses during the night cannot be controlled easily e.g. West-facing, angled glazing, skylights
•    Thermal losses through non-insulated or unprotected glazing
•    Lack of adequate shading during seasonal periods of high solar gain (especially on the West wall)
•    Incorrect application of thermal mass to modulate daily temperature variations
•    Open staircases leading to unequal distribution of warm air between upper and lower floors as warm air rises
•    High building surface area to volume - Too many corners
•    Inadequate weatherization leading to high air infiltration
•    Lack of, or incorrectly-installed, radiant barriers during the hot season
•    Insulation materials that are not matched to the main mode of heat transfer (e.g. undesirable convective/conductive/radiant heat transfer)

Sustainable building materials

Some examples of sustainable building materials include recycled denim or blown-in fiber glass insulation, sustainably harvested wood, Trass, Linoleum, sheep wool, concrete (high and ultra high performance roman self-healing concrete), panels made from paper flakes, baked earth, rammed earth, clay, vermiculite, flax linen, sisal, sea grass, cork, expanded clay grains, coconut, wood fiber plates, calcium sand stone, locally-obtained stone and rock, and bamboo, which is one of the strongest and fastest growing woody plants, and non-toxic low-VOC glues and paints.

Waste management

Waste takes the form of spent or useless materials generated from households and businesses, construction and demolition processes, and manufacturing and agricultural industries. These materials are loosely categorized as municipal solid waste, construction and demolition (C&D) debris, and industrial or agricultural by-products. Sustainable architecture focuses on the on-site use of waste management, incorporating things such as grey water systems for use on garden beds, and composting toilets to reduce sewage. These methods, when combined with on-site food waste composting and off-site recycling, can reduce a house's waste to a small amount of packaging waste.

Structure and materials recycling

Some sustainable architecture incorporates the use of recycled or second hand materials, such as reclaimed lumber. The reduction in use of new materials creates a corresponding reduction in embodied energy (energy used in the production of materials). Often sustainable architects attempt to retro-fit old structures to serve new needs in order to avoid unnecessary development. Architectural salvage and reclaimed materials are used when appropriate.

When older buildings are demolished, frequently any good wood is reclaimed, renewed, and sold as flooring. Any good dimension stone is similarly reclaimed. Many other parts are reused as well, such as doors, windows, mantels, and hardware, thus reducing the consumption of new goods.

When new materials are employed, green designers look for materials that are rapidly replenished, such as bamboo, which can be harvested for commercial use after only 6 years of growth, sorghum or wheat straw, both of which are waste material that can be pressed into panels, or cork oak, in which only the outer bark is removed for use, thus preserving the tree. When possible, building materials may be gleaned from the site itself; for example, if a new structure is being constructed in a wooded area, wood from the trees which were cut to make room for the building would be re-used as part of the building itself.

Source: Wikipedia

Sustainable development is a pattern of resource use that aims to meet human needs while preserving the environment so that these needs can be met not only in the present, but also by future generations. The term was used by the Brundtland Commission which coined what has become the most often-quoted definition of sustainable development as development that "meets the needs of the present without compromising the ability of future generations to meet their own needs."

Sustainable development ties together concern for the carrying capacity of natural systems with the social challenges facing humanity. As early as the 1970s "sustainability" was employed to describe an economy "in equilibrium with basic ecological support systems." Ecologists have pointed to the “limits of growth” and presented the alternative of a “steady state economy” in order to address environmental concerns.

The field of sustainable development can be conceptually broken into three constituent parts: environmental sustainability, economic sustainability and sociopolitical sustainability.

Scheme of sustainable development: at the confluence of three constituent parts.

Source: Wikipedia

Tidal power, sometimes called tidal energy, is a form of hydropower that converts the energy of tides into electricity or other useful forms of power.

Although not yet widely used, tidal power has potential for future electricity generation. Tides are more predictable than wind energy and solar power. Historically, tide mills have been used, both in Europe and on the Atlantic coast of North America. The earliest occurrences date from the Middle Ages, or even from Roman times.

Toxicity is the degree to which a substance is able to damage an exposed organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell (cytotoxicity) or an organ (organotoxicity), such as the liver (hepatotoxicity). By extension, the word may be metaphorically used to describe toxic effects on larger and more complex groups, such as the family unit or society at large.

A central concept of toxicology is that effects are dose-dependent; even water can lead to water intoxication when taken in large enough doses, whereas for even a very toxic substance such as snake venom there is a dose below which there is no detectable toxic effect.

There are generally three types of toxic entities; chemical, biological, and physical:

•    Chemicals include inorganic substances such as lead, mercury, asbestos, hydrofluoric acid, and chlorine gas, organic compounds such as methyl alcohol, most medications, and poisons from living things.
•    Biological toxic entities include those bacteria and viruses that are able to induce disease in living organisms. Biological toxicity can be complicated to measure because the "threshold dose" may be a single organism. Theoretically one virus, bacterium or worm can reproduce to cause a serious infection. However, in a host with an intact immune system the inherent toxicity of the organism is balanced by the host's ability to fight back; the effective toxicity is then a combination of both parts of the relationship. A similar situation is also present with other types of toxic agents.
•    Physically toxic entities include things not usually thought of under the heading of "toxic" by many people: direct blows, concussion, sound and vibration, heat and cold, non-ionizing electromagnetic radiation such as infrared and visible light, and ionizing radiation such as X-rays and alpha, beta, and gamma radiation.

Toxicity can be measured by the effects on the target (organism, organ, tissue or cell). Because individuals typically have different levels of response to the same dose of a toxin, a population-level measure of toxicity is often used which relates the probability of an outcome for a given individual in a population. One such measure is the LD50.

When such data does not exist, estimates are made by comparison to known similar toxic things, or to similar exposures in similar organisms. Then "safety factors" are added to account for uncertainties in data and evaluation processes. For example, if a dose of toxin is safe for a laboratory rat, one might assume that one tenth that dose would be safe for a human, allowing a safety factor of 10 to allow for interspecies differences between two mammals; if the data are from fish, one might use a factor of 100 to account for the greater difference between two chordate classes (fish and mammals).

Similarly, an extra protection factor may be used for individuals believed to be more susceptible to toxic effects such as in pregnancy or with certain diseases. Or, a newly synthesized and previously unstudied chemical that is believed to be very similar in effect to another compound could be assigned an additional protection factor of 10 to account for possible differences in effects that are probably much smaller. Obviously, this approach is very approximate; but such protection factors are deliberately very conservative and the method has been found to be useful in a wide variety of applications.

Assessing all aspects of the toxicity of cancer-causing agents involves additional issues, since it is not certain if there is a minimal effective dose for carcinogens, or whether the risk is just too small to see. In addition, it is possible that a single cell transformed into a cancer cell is all it takes to develop the full effect (the "one hit" theory).

It is more difficult to assess the toxicity of chemical mixtures than of single, pure chemicals because each component displays its own toxicity and components may interact to produce enhanced or diminished effects. Common mixtures include gasoline, cigarette smoke, and industrial waste. Even more complex are situations with more than one type of toxic entity, such as the discharge from a malfunctioning sewage treatment plant, with both chemical and biological agents.

Source: Wikipedia

Veganism is a diet and lifestyle that seeks to exclude the use of animals for food, clothing, or any other purpose. Vegans endeavor not to use or consume animal products of any kind. The most common reasons for becoming a vegan are ethical commitment or moral conviction concerning animal rights, the environment, human health, and spiritual or religious concerns. Of particular concern to many vegans are the practices involved in factory farming and animal testing, and the intensive use of land and other resources for animal farming.

Vegan diets (sometimes called strict or pure vegetarian diets) are a subset of vegetarian diets. Properly planned vegan diets are healthful and have been found to satisfy nutritional needs. Poorly planned vegan diets can be low in levels of calcium, iodine, vitamin B12 and vitamin D. Vegans are therefore encouraged to plan their diet and take dietary supplements as appropriate. Various polls have reported vegans to be between 0.2% and 1.3% of the U.S. population, and between 0.25% and 0.4% of the UK population.

Source: Wikipedia

Vegetarianism is the practice of following a diet based on plant-based foods including fruits, vegetables, cereal grains, nuts, and seeds, with or without dairy products and eggs. Vegetarians do not eat meat, game, poultry, fish, crustaceans, shellfish, or products of animal slaughter. Variants of the diet exclude eggs and/or products coming from animal labor, such as dairy products and honey. A vegan diet is a form of vegetarian diet which excludes all animal products, including dairy products, eggs, and honey. Most vegetarians consume dairy products, and many eat eggs. A lacto-vegetarian diet includes dairy products but excludes eggs, an ovo-vegetarian diet includes eggs but not dairy, and a lacto-ovo vegetarian diet includes both eggs and dairy products.

A semi-vegetarian diet consists largely of vegetarian foods, but may include fish and sometimes poultry, as well as dairy products and eggs. A pescetarian diet, for example, includes fish but no meat. The association of semi-vegetarianism with vegetarianism in popular vernacular has led vegetarian groups such as the Vegetarian Society to note these diets are not vegetarian.

Vegetarianism may be adopted for ethical, health, environmental, religious, political, cultural, aesthetic, economic, or other reasons.

Source: Wikipedia

Water is a ubiquitous chemical substance that is composed of hydrogen and oxygen and is essential for all known forms of life.
In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, as ice, and a gaseous state as water vapor or steam. Water covers 71% of the Earth's surface. On Earth, it is found mostly in oceans and other large water bodies, with 1.6% of water below ground in aquifers and 0.001% in the air as vapor, clouds (formed of solid and liquid water particles suspended in air), and precipitation. Oceans hold 97% of surface water, glaciers and polar ice caps 2.4%, and other land surface water such as rivers, lakes and ponds 0.6%. A very small amount of the Earth's water is contained within biological bodies and manufactured products.
Water moves continually through a cycle of evaporation or transpiration (evapotranspiration), precipitation, and runoff, usually reaching the sea. Over land, evaporation and transpiration contribute to the precipitation over land.
Clean, fresh drinking water is essential to human and other life forms. Access to safe drinking water has improved steadily and substantially over the last decades in almost every part of the world. There is a clear correlation between access to safe water and GDP per capita. However, some observers have estimated that by 2025 more than half of the world population will be facing water-based vulnerability. Water plays an important role in the world economy, as it functions as a solvent for a wide variety of chemical substances and facilitates industrial cooling and transportation. Approximately 70 percent of freshwater is consumed by agriculture.
Water fit for human consumption is called drinking water or potable water. Water that is not potable can be made potable by filtration or distillation (heating it until it becomes water vapor, and then capturing the vapor without any of the impurities it leaves behind), or by other methods (chemical or heat treatment that kills bacteria). Sometimes the term safe water is applied to potable water of a lower quality threshold (i.e., it is used effectively for nutrition in humans that have weak access to water cleaning processes, and does more good than harm). Water that is not fit for drinking but is not harmful for humans when used for swimming or bathing is called by various names other than potable or drinking water, and is sometimes called safe water, or "safe for bathing". Chlorine is a skin and mucous membrane irritant that is used to make water safe for bathing or drinking. Its use is highly technical and is usually monitored by government regulations (typically 1 part per million (ppm) for drinking water, and 1–2 ppm of chlorine not yet reacted with impurities for bathing water).
This natural resource is becoming scarcer in certain places, and its availability is a major social and economic concern. Currently, about a billion people around the world routinely drink unhealthy water. Most countries accepted the goal of halving by 2015 the number of people worldwide who do not have access to safe water and sanitation during the 2003 G8 Evian summit. Even if this difficult goal is met, it will still leave more than an estimated half a billion people without access to safe drinking water and over a billion without access to adequate sanitation. Poor water quality and bad sanitation are deadly; some five million deaths a year are caused by polluted drinking water. The World Health Organization estimates that safe water could prevent 1.4 million child deaths from diarrhea each year. Water, however, is not a finite resource but; it re-circulates as potable water through precipitation in quantities many degrees of magnitude higher than human consumption
In the developing world, 90% of all wastewater still goes untreated into local rivers and streams. Some 50 countries, with roughly a third of the world’s population, also suffer from medium or high water stress, and 17 of these extract more water annually than is recharged through their natural water cycles. The strain not only affects surface freshwater bodies like rivers and lakes, but it also degrades groundwater resources.

Source: Wikipedia

Wave power is energy produced by the movement of waves.

Whole foods are foods in their natural state: unrefined, unprocessed and unadulterated. They do not contain additives, preservatives or additional ingredients such as artificial sweeteners, high fructose corn syrup and added sugar; artificial colors; salt; and added fats and trans fats.
Whole foods are not necessarily organic, nor are organic foods necessarily whole foods (although they can be). Unprocessed grains, fruits and vegetables, unprocessed meat and non-homogenized milk are all examples of whole foods.
Because whole foods are not chemically preserved or treated, they have a relatively short shelf life and are difficult to transport over long distances. Many foods sold at local farmers' markets are whole foods.
Whole food supplements are nutritional supplements frequently containing powdered fruits, vegetables and grains that are designed to provide vitamins, minerals, amino acids or other nutrients. Under the Dietary Supplement Health and Education Act of 1994 (DSHEA), the U.S. Food and Drug Administration (FDA) regulates dietary supplements as foods, not as drugs. Whole food supplements may not claim to cure, mitigate, or treat a disease. In Europe, the Food Supplements Directive requires that supplements be demonstrated to be safe, both in quantity and quality, and they may be labeled with health claims in some areas.

Wind power is the conversion of wind energy into a useful form of energy, such as electricity, using wind turbines. At the end of 2008, worldwide nameplate capacity of wind-powered generators was 121.2 gigawatts (GW). In 2008, wind power produced about 1.5% of worldwide electricity usage; and is growing rapidly, having doubled in the three years between 2005 and 2008. Several countries have achieved relatively high levels of wind power penetration, such as 19% of stationary electricity production in Denmark, 11% in Spain and Portugal, and 7% in Germany and the Republic of Ireland in 2008. As of May 2009, eighty countries around the world are using wind power on a commercial basis.

Large-scale wind farms are connected to the electric power transmission network; smaller facilities are used to provide electricity to isolated locations. Utility companies increasingly buy back surplus electricity produced by small domestic turbines. Wind energy as a power source is attractive as an alternative to fossil fuels, because it is plentiful, renewable, widely distributed, clean, and produces no greenhouse gas emissions. However, the construction of wind farms is not universally welcomed because of their visual impact and other effects on the environment.

Wind power is non-dispatchable, meaning that for economic operation, all of the available output must be taken when it is available. Other resources, such as hydropower, and standard load management techniques must be used to match supply with demand. The intermittency of wind seldom creates problems when using wind power to supply a low proportion of total demand. Where wind is to be used for a moderate fraction of demand such as 40%, additional costs for compensation of intermittency are considered to be modest.

Source: Wikipedia

A wind turbine is a rotating machine which converts the kinetic energy of wind into mechanical energy. If the mechanical energy is used directly by machinery, such as a pump or grinding stones, the machine is usually called a windmill. If the mechanical energy is instead converted to electricity, the machine is called a wind generator, wind turbine, wind power unit (WPU), wind energy converter (WEC), or aerogenerator.

Turbines used in wind farms for commercial production of electric power are usually three-bladed and pointed into the wind by computer-controlled motors. These have high tip speeds of over 200 miles per hour, high efficiency, and low torque ripple, which contribute to good reliability. The blades are usually colored light gray to blend in with the clouds and range in length from 20 to 40 meters (65 to 130 ft) or more. The tubular steel towers range from 200 to 300 feet (60 to 90 meters) tall. The blades rotate at 10-22 revolutions per minute. At 22 rotations per minute the tip speed exceeds 300 ft per second. A gear box is commonly used to step up the speed of the generator, although designs may also use direct drive of an annular generator. Some models operate at constant speed, but more energy can be collected by variable-speed turbines which use a solid-state power converter to interface to the transmission system. All turbines are equipped with shut-down features to avoid damage at high wind speeds.

Wool is a fibrous protein derived from the specialized skin cells called follicles. The wool is taken from animals in the Caprinae family, principally sheep, but the hair of certain species of other mammals including: goats, llamas, and rabbits may also be called wool. Wool has several qualities that distinguish it from hair or fur: it is crimped, it has a different texture or handle, it is elastic, and it grows in staples (clusters).

Wool's scaling and crimp make it easier to spin the fleece by helping the individual fibers attach to each other, so that they stay together. Because of the crimp, wool fabrics have a greater bulk than other textiles, and retain air, which causes the product to retain heat. Insulation also works both ways; Bedouins and Tuaregs use wool clothes to keep the heat out.

The amount of crimp corresponds to the fineness of the wool fibers. A fine wool like Merino may have up to a hundred crimps per inch, while the coarser wools like karakul may have as few as one to two crimps per inch. Hair, by contrast, has little if any scale and no crimp, and little ability to bind into yarn. On sheep, the hair part of the fleece is called kemp. The relative amounts of kemp to wool vary from breed to breed, and make some fleeces more desirable for spinning, felting, or carding into batts for quilts or other insulating products.

Wool fibers are hygroscopic, meaning they readily absorb and give off moisture. Wool can absorb moisture almost one-third of its own weight. Wool absorbs sound like many other fabrics. Wool is generally a creamy white color, although some breeds of sheep produce natural colors such as black, brown, silver, and random mixes.

Wool ignites at a higher temperature than cotton fibers and some synthetics. It has lower rate of flame spread, low heat release, low heat of combustion, and doesn't melt or drip; it forms a char which is insulating and self-extinguishing, and contributes less to toxic gases and smoke than other flooring products, when used in carpets. Wool carpets are specified for high safety environments, such as trains and aircraft. Wool is usually specified for garments for fire-fighters, soldiers, and others in occupations where they are exposed to the likelihood of fire.

Wool is static electricity resistant, as the retention of moisture within the fabric prevents a build up of static. Wool garments are much less likely to spark or cling to the body. The use of wool car seat covers or carpets reduces the risk of a shock when a person touches a grounded object. Wool is considered by the medical profession to be hypoallergenic.

Keeping with the times, organic wool is becoming more and more popular. This wool is very limited in supply and much of it comes from New Zealand and Australia. Organic wool is becoming easier to find in clothing and other products, though these products often carry a higher price. Wool is environmentally preferable (as compared to petroleum-based Nylon or Polypropylene) as a material for carpets as well, in particular when combined with a natural binding and the use of formaldehyde-free glues.

Source: Wikipedia

Zero waste is a philosophy that encourages the redesign of resource life cycles, so that all products are reused. Any trash sent to landfills is minimal. The process recommended is one similar to the way in which resources are reused in nature.

In industry, this process involves creating commodities out of traditional waste products, essentially transforming old outputs into new inputs for similar or different industrial sectors. An example might be the cycle of a glass milk bottle. The primary input (or resource) is silica-sand, which is formed into glass and then into a bottle. The bottle is filled with milk and distributed to the consumer. At this point, normal waste methods would see the bottle disposed in a landfill or similar. But with a zero-waste method, the bottle can be saddled at the time of sale with a deposit, which is returned to the bearer upon redemption. The bottle is then washed, refilled, and resold. The only material waste is the wash water, and energy loss has been minimized.

Zero waste can represent an economical alternative to waste systems, in which new resources are continually required to replenish wasted raw materials. It can also represent an environmental alternative to waste since waste represents a significant amount of pollution in the world (garbage patch).

Despite the similarities, zero waste is not just another form of recycling; it involves changing things at the production level.

Take a personal computer: in its constituent parts, (steel, copper, glass, etc.) fairly inexpensive; yet once built into a computer, worth much more. However, millions of PCs are disposed of worldwide each year (160 million in 2007). By adopting a modular design policy, (e.g. each aspect of the computer is a separate pluggable element) old computer components can be reused in newer products.

Zero waste depends on the redesign of industrial, commercial and consumer goods. Recycling contents itself with attempts to deal with wastes as delivered, after goods have become waste. Zero waste does not accept the unthinking creation of waste, followed by a scramble to capture materials.

The first city to apply this concept was Canberra, Australia, which in 1995 started its “Zero Waste in 2010” program. The city of San Francisco, in the United States, which has 7,000,000 inhabitants, also adopted this concept at the same time, and has managed to reduce its urban waste by 50% in 10 years.

Today there are several companies that have established zero waste goals. For example, Wal-Mart’s goal is to become completely sustainable in two years: they are trying to use less plastic, reduce the number of trash compactors, and look for cost-efficient ways to recycle items from their computer and jewelry departments.

Source: Wikipedia

Sources

Wikipedia

Sitios Espana not English

IPCC Glossary

UNFCCC

Super Eco Glossary

Instituto para la Diversificación y Ahorro de Energía

Footprint Network

American Wind Energy Association

Wind Energy Development

UNFCCC pages on the Kyoto Protocol

Vampire Power - Grinning Planet

Standby Power - Wikipedia

Benefits of Recycling

International Institute for Sustainable Development