Area on the surface of the earth between tropic and temperate regions, approximately between 40 degrees N. and S.Search the Web for Abrupt Climate Change
Any portion of the electromagnetic spectrum (including visible light) that is trapped by free atoms or molecules in the path of the radiation,so reducing their transmission. In the climate context, this is important for the greenhouse effect since water vapor, carbon dioxide and methane absorb certain wavelengths of infrared radiation.Search the Web for Absorption Lines
Molecules of acid formed from reactions high in the atmosphere involving nitrogen, sulfur oxides, and water vapor that settle out of the atmosphere without any additional water.Search the Web for Acid Fallout
Acid Free is used to describe paper which is free from traces of acid; e.g. made under neutral sizing conditions. This helps improve its longevity.Search the Web for Acid Free
Rainwater that has an acidity content greater than the postulated natural pH of about 5.6. It is formed when sulfur dioxides and nitrogen oxides, as gases or fine particles in the atmosphere, combine with water vapor and precipitate as sulfuric acid or nitric acid in rain, snow, or fog. The dry forms are acidic gases or particulates.Search the Web for Acid Rain
This is the most commonly used adsorption medium, produced by heating carbonaceous substances or cellulose bases in the absence of air. It has a very porous structure and is commonly used to remove organic matter and dissolved gases from water. Its appearance is similar to coal or peat. Available in granular, powder or block form; in powder form it has the highest adsorption capacity.Search the Web for Activated Coal
A biological wastewater treatment process in which a mixture of waste water and activated sludge is agitated and aerated. The activated sludge is then separated from the treated wastewater by sedimentation and disposed of or returned to the process as needed.Search the Web for Activated Sludge Process
Active Ventilation is forced air ventilation, this is where a fan is used to move air into a space or room to provide ventilation.Search the Web for Active Ventilation
The ability of a system (like an ecosystem) to adapt to climate change
or other environmental disturbances. This may mean moderating potential
damages, taking advantage of opportunities or coping with the
In discussions on global warming adaptive capacity often refers to a country. In this case it is currently much lower in developing countries, consequential to poverty.
The horizontal movement of heat energy. A warm breeze through a relatively cool orchard, for instance.Search the Web for Advection
A water treatment pond that speeds up biological decomposition of organic waste by stimulating the growth and activity of bacteria, which are responsible for the degradation.Search the Web for Aerated Lagoon
Tiny organisms living in the atmosphere. Certain small seeds, bacteria, and spores are examples.Search the Web for Aeroplankton
Particulate matter, solid or liquid, larger than a molecule but small enough to remain suspended in the atmosphere.Search the Web for Aerosol
A term coined by Australian writer Clive Hamilton to describe a society where the pursuit of material wealth has led to a lower quality of life with more unhappiness, depression and mental illness due to lack of community and the pressure to get rich.Search the Web for Affluenza
Planting of new forests on lands that have not been recently forested.Search the Web for Afforestations
A business that markets farm products and equipment, including warehousing, seed monopolization, and fertilizer. The corporatization of farming, resulting in a handful of very large non-local companies owning and managing--and in some cases ruining--millions of high-yield acresSearch the Web for Agribusiness
Production of tree crops in a manner similar to agriculture. Also, production of trees along with regular cropSearch the Web for Agroforestry
A material often installed around the frame of a building to prevent or reduce the infiltration of air into the interior which could be too hot, too cold or too humid for comfort.Search the Web for Air Barrier
Air pollution occurs when the air contains gases, dust, fumes or odour in harmful amounts. That is, amounts which could be harmful to the health or comfort of humans and animals or which could cause damage to plants and materials.
The substances that cause air pollution are called pollutants. Pollutants that are pumped into our atmosphere and directly pollute the air are called primary pollutants. Primary pollutant examples include carbon monoxide from car exhausts and sulfur dioxide from the combustion of coal.
Further pollution can arise if primary pollutants in the atmosphere undergo chemical reactions. The resulting compounds are called secondary pollutants. Photochemical smog is an example of this.Search the Web for Air Pollution
Air sealing refers to the steps undertaken to prevent uncontrolled inward or outward air leakage via the building envelope.Search the Web for Air Sealing
This is the tendency of heated air to rise and to arrange itself in layers with the warmest air at the top. The assumption here is that there are no external wind sources to keep mixing the air and that the air is in an enclosed space.
A term encountered in passive solar design.Search the Web for Air Stratification
An area characterized by air with common qualities. Compare Watershed.Search the Web for Airshed
Area on the surface of the earth between tropic and temperate regions, approximately between 40 degrees N. and S.Search the Web for Albedo
The ratio of reflected to incident light; albedo can be expressed as either a percentage or a fraction of 1. Snow covered areas have a high albedo (up to about 0.9 or 90%) due to their white color, while vegetation has a low albedo (generally about 0.1 or 10%) due to the dark color and light absorbed for photosynthesis. Clouds have an intermediate albedo and are the most important contributor to the Earth's albedo. The Earth's aggregate albedo is approximately 0.3.Search the Web for Albedo
Alcohol can be blended with gasoline for use as transportation fuel. It may be produced from a wide variety of organic feedstock. The common alcohol fuels are methanol and ethanol. Methanol may be produced from coal, natural gas, wood and organic waste. Ethanol is commonly made from agricultural plants, primarily corn, containing sugar.Search the Web for Alcohol Fuels
A group of highly reactive chemical compounds used in making resins and dyes. Volatile organic compounds (VOCs). One of the better-known members of this group is formaldehyde.Search the Web for Aldehydes
The metabolic impact of one plant on another, whether beneficial or harmful. Example: eucalyptus tree toxins that inhibit the growth of certain plants.Search the Web for Allelopathy
Something organic imported into an ecosystem from outside of it (e.g., nutrients brought by streams or blown in on the wind). Contrasts with Autochthonous.Search the Web for Allochthonous
The Alpaca (Vicugna pacos) is a domesticated species of South American camelid. This is an animal that produces a thick, full coat which makes incredibly warm jackets, sweaters, hats and blankets. Alpaca fiber is stronger, lighter and more resilient than wool. It’s also finer than cashmere and equal to the warmth of Gortex.Search the Web for Alpaca
Energy derived from nontraditional sources (e.g., compressed natural gas, solar, hydroelectric, wind).Search the Web for Alternative Energy
Energy derived from nontraditional sources (e.g., compressed natural gas, solar, hydroelectric, wind).Search the Web for Alternative Energy
Fuels from sources cleaner than coal or petroleum products: ethanol, methanol, natural gas, solar, wind, geothermal, biodiesel from vegetable oil, etc.Search the Web for Alternative Fuels
Area on the surface of the earth between tropic and temperate regions, approximately between 40 degrees N. and S.Search the Web for Ambient Temperature
A colorless, pungent, gas that is extremely soluble in water and may be used as a refrigerant. It is also a fixed form of nitrogen that is suitable as fertilizer.Search the Web for Ammonia
A renewable energy technology that generates heat and electricity from waste organic matter.
Anaerobic digestors follow the same principles as landfill gas capture systems, capturing the methane released by decomposing organic waste such as food or slurry and then burning it to create heat and electricity. The resulting residue can also then be used as a fertilizer.
The technology is becoming increasingly popular across the agricultural sector and advocates claim that it is more cost effective than many alternative renewable energy systems.Search the Web for Anaerobic Digestor
The angle of relative air flow to the blade chord.Search the Web for Angle Of Attack
The angle that a ray of sun makes with a line perpendicular to the surface. For example, a surface that directly faces the sun has a solar angle of incidence of zero, but if the surface is parallel to the sun (for example, sunrise striking a horizontal rooftop), the angle of incidence is 90°.Search the Web for Angle Of Incidence
The steepest angle that slope, rock, or detritus material settles into without toppling.Search the Web for Angle Of Repose
The annual solar savings of a solar building is the energy savings attributable to a solar feature relative to the energy requirements of a non-solar building.Search the Web for Annual Solar Savings
A biologic response to exposure to multiple substances that is less than would be expected if the known effects of the individual substances were added together.
See ATSDR Glossary of Terms
A hard coal containing little volatile matter.Search the Web for Anthracite
Often abbreviated to just AGW. This is global warming which has been caused by human activity in addition to natural global warming.
The science around this is difficult to prove, as identifying a clear indicator of the human contribution which is independent of multiple natural causes is very hard to do in reality. The human element to global warming needs to be clearly and precisely measured against a background of natural global warming that has been occurring since the last ice age.
spiritual philosophy based on the teachings of Rudolf Steiner (25 February 1861 - 30 March 1925) which postulates the existence of an objective, intellectually comprehensible spiritual world accessible to direct experience through inner development - more specifically through cultivating conscientiously a form of thinking independent of sensory experience. Steiner was the initiator of biodynamic gardening.Search the Web for Anthroposophy
Cultivation of aquatic plants or animals for harvest and utilization by humans. Usually aquaculture refers to fresh water cultivation, while mariculture refers to seawater cultivationSearch the Web for Aquaculture
Rock formations impermeable to groundwater.Search the Web for Aquiclude
The underground layer of water-soaked sand and rock that acts as a water source for a well; described as artesian (confined) or water table (unconfined).Search the Web for Aquifer
A termed coined by Italian architect Paolo Soleri in 1959 to describe the concept of architecture and ecology working as an integral system. Arcology designs are fully 3-dimensional mega-structure cities which can (theoretically) achieve much greater efficiencies, and promote more social interaction than 2-dimensional cities, while using far less land and consuming fewer resources.Search the Web for Arcology
The northern limit of tree growth; the sinuous boundary between tundra and boreal forest.Search the Web for Artic Treeline
"Artificial trees" are a geo-engineering solution that use amine solutions to capture CO2 out of the atmosphere and sequester it underground.
Also known as "air capture" or "carbon scrubbers", the technology is currently in its formative stages but researchers in the US estimate one tree could take as much as 25 times more CO2 out of the atmosphere each year than a normal tree.
A handful of startups are currently looking to bring the technology to market.Search the Web for Artificial Trees
A mineral fiber that can pollute air or water and cause cancer or asbestosis when inhaled. In most countries it is banned or severely restricted in its use in manufacturing and construction.Search the Web for Asbestos
A disease associated with inhalation of asbestos fibers. The disease makes breathing progressively more difficult and can be fatal.Search the Web for Asbestosis
A mathematical model for quantitatively describing, simulating, and analyzing the structure of the circulation in the atmosphere and the underlying causes. Sometimes referred to as Atmospheric General Circulation Models or AGCMs (See GCMs as well).Search the Web for Atmospheric Circulation Model
This is usually the quantity of greenhouse gases relative to the global volume of the atmosphere, expressed in parts per million (ppm). Atmospheric concentrations are often cited for carbon dioxide (CO2) alone or for CO2 equivalents, in which case they are adjusted to reflect all greenhouse gases. Rising atmospheric concentrations can occur even with unchanged levels of annual greenhouse gas emissions.Search the Web for Atmospheric Concentrations
A coral island consisting of a ring of coral surrounding a central lagoon. Atolls are common in the Indian and Pacific Oceans.Search the Web for Atoll
The phenomenon of the spontaneous initiation of convection in an atmospheric layer in which the lapse rate is equal to or greater than the autoconvective lapse rate.Search the Web for Autoconvection
Literally, "self eater." Organisms capable of producing their own food. See primary producers . Contrast with heterotroph .Search the Web for Autotrophn
The availability factor of a power plant is the amount of time that it is able to produce electricity over a certain period, divided by the amount of the time in the period. Occasions where only partial capacity is available may or may not be deducted. The availability factor should not be confused with capacity factor.Search the Web for Availability Factor
The amount of heat energy that may be converted into useful energy from a fuel.Search the Web for Available Heat
The cost a utility would incur to generate the next increment of electric capacity using its own resources; many landfill gas projects' buy back rates are based on avoided costs.Search the Web for Avoided Cost
An alternator design where a flat disc carrying magnets on the face (the Armature) rotates near a flat disc carrying coils (the Stator).Search the Web for Axial Alternator
The angle between true south and the point on the horizon directly below the sun.Search the Web for Azimuth Angle