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The
effects of climate change on plants and animals are difficult
to measure, but potentially dramatic. Many species inhabit
precisely bounded ecological niches, and even small changes
in climate may cause fundamental disruptions in habitat or food
availability. In the past, animals could respond to these pressures
by moving from one place to another. Today, however, land development
has constrained and fragmented ranges and travel routes, making
species migration in response to climate change much more difficult.
Moreover, loss of key predator or prey species may affect the
life cycles of other organisms in the food chain.
Organic processes can also play an important role in regulating
the earth’s climate. Changes in the extent of snow, ice,
or vegetation covering the planet’s surface can alter key
climatic processes with unforeseeable effects (changing the
amount of carbon dioxide consumed by plants, for example, or
the proportion of the sun’s heat absorbed by the earth).
Biological evidence can also help researchers understand other
processes. Sometimes, people keep records that offer clues to
climate patterns—the changing dates of bird migrations,
for instance, or the onset of spring. Other records that come
from nature—such as tree rings, preserved bones, and fish
scales in ocean sediments—go back farther than more direct
measures of climate, making them valuable indicators of climate
change.
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•
United
States Geological Survey (USGS)/Status and
Trends of the Nation’s Biological Resources
- This report, written by scientists in
nontechnical language, includes an excellent
essay about climate change, forecasting,
models, and biology.
•
United
States Environmental Protection Agency (EPA)
Global Warming Site - Includes downloadable
teaching resources and a searchable data
base of materials for educators, as well
as descriptions of potential impacts on
various environments.
•
Global
Warming: Early Warning Signs - This
world map, created by the Union of Concerned
Scientists, shows local signs of global
change, with clickable “hot spots.”
• U.S.
Global Change Research Program: National
Assessment of the Potential Consequences
of Climate Variability and Change -
Detailed reports on the possible effects
on agriculture, forests, and coastal and
marine resources.
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