Adaptation: An adjustment in natural or human systems to a new or chang-
ing environment. Adaptation to climate change refers to adjustment
in natural or human systems in response to actual or expected cli-
Aerosols: Tiny bits of liquid or solid matter suspended in air. They come
from natural sources such as erupting volcanoes and from waste
gases emitted from automobiles, factories, and power plants. By
reecting sunlight, aerosols cool the climate and offset some of the
warming caused by greenhouse gases.
Albedo: The relative reectivity of a surface. A surface with high albedo
reects most of the light that shines on it and absorbs very little
energy; a surface with a low albedo absorbs most of the light energy
that shines on it and reects very little.
Anthropogenic: Made by people or resulting from human activities. This
term is usually used in the context of emissions that are produced as
a result of human activities.
Atmosphere: The thin layer of gases that surrounds the earth and allows
living organisms to breathe. It reaches 400 miles (644 km) above the
surface, but 80 percent is concentrated in the troposphere—the lower
7 miles (11 km) above the earth’s surface.
Baseline: The emission of greenhouse gases that would occur without the
contemplated policy intervention or project activity.
Biodiversity: Different plant and animal species.
Biomass: Plant material that can be used for fuel.
Bleaching (coral): The loss of algae from corals that causes the corals to turn
white. This is one of the results of global warming and signies a
die-off of unhealthy coral.
Carbon cycle: A complex series of processes through which all of the carbon
atoms in existence rotate. It is the biogeochemical cycle by which car-
bon is exchanged among the biosphere (living things), pedosphere
(soil component), geosphere (earth processes), hydrosphere (water
processes), and atmosphere of the earth. One of the most important
cycles of all the natural earth processes, it allows for carbon to be
recycled and reused.
Carbon dioxide (CO
): A colorless, odorless gas that forms when carbon
atoms combine with oxygen atoms. Carbon dioxide is a tiny, but
vital, part of the atmosphere. The heat-absorbing ability of carbon
dioxide is what makes life possible on earth.
Carbon dioxide equivalent (CO
e): The universal unit of measurement
used to indicate the global warming potential of each of the six