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Unit 12: Earth's Changing Climate // Glossary

aerosols
Liquid or solid particles that are suspended in air or a gas. Also referred to as particulate matter.
albedo
The fraction of electromagnetic radiation reflected after striking a surface.
anthropogenic
Describing effects or processes that are derived from human activities, as opposed to effects or processes that occur in the natural environment without human influences.
coral bleaching
Refers to the loss of color of corals due to stress-induced expulsion of symbiotic, unicellular algae called zooxanthellae that live within their tissues. Stress can be induced by: (1) increased water temperatures (often attributed to global warming), (2) starvation caused by a decline in zooplankton levels as a result of overfishing, (3) solar irradiance (photosynthetically active radiation and ultraviolet band light), (4) changes in water chemistry, (5) silt runoff, or (6) pathogen infections.
deforestation
Removal of trees and other vegetation on a large scale, usually to expand agricultural or grazing lands.
United Nations Framework Convention on Climate Change
A treaty signed by nations at the Earth Summit in 1992 to stabilize and reduce greenhouse gas emissions. In 1997 the Kyoto Protocol, an agreement among 150 nations, was added, setting specific reduction levels.
global warming potential
A measure of how much a given mass of greenhouse gas is estimated to contribute to global warming. Compares the gas in question to that of the same mass of carbon dioxide.
Intergovernmental Panel on Climate Change (IPCC)
Established in 1988 by two United Nations organizations to assess the risk of human-induced climate change.
Kyoto Protocol
An amendment to the international treaty on climate change, assigning mandatory targets for the reduction of greenhouse gas emissions to signatory nations.
paleoclimate
Referring to past climates of the Earth.
permafrost
Soil that stays in a frozen state for more than two years in a row.
radiocarbon dating
A radiometric dating method that uses the naturally occurring isotope carbon-14 to determine the age of carbonaceous materials up to about 60,000 years.
residence time
A broadly useful concept that expresses how fast something moves through a system in equilibrium; the average time a substance spends within a specified region of space, such as a reservoir. For example, the residence time of water stored in deep groundwater, as part of the water cycle, is about 10.000 years.
sinks
Habitats that serve to trap or otherwise remove chemicals such as plant nutrients, organic pollutants, or metal ions through natural processes.

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