Climate Change and Society
Climate change is
expected to affect
virtually every sector
of society, including
water resources, food
production, energy use,
transportation and
commerce, recreation,
and even national
security. While some of
these effects could be
beneficial, particularly
in the short term, many
of the impacts could
be costly, far-reaching,
and damaging to local
communities and society
as a whole in the long
term. This fact sheet
describes some of the
ways that climate
change affects society.
United States
Environmental Protection
Agency
Water Resources
Changing weather patterns affect both the amount and quality of water resources avai able for drinking,
irrigation, fish farming, power generation, shipping, recreation, and other uses. Rising temperatures are
already decreasing the size of snowpack in the western United States. Over time, this reduced snowpack
could affect seasona water supplies in regions that depend on this source of water. Droughts can have
simi ar effects in areas where water supplies are a ready scarce, such as the U.S. Southwest. In addition,
floods and severe storms—which will become more frequent because of climate change—can compromise
the quality of water supplies by washing chemicals and other contaminants into lakes, rivers, and streams.
Coastal Communities at Risk
The impacts from climate change are expected to be particularly noticeable to people
who live, work, and engage in recreational activities along the coast. Average global
sea levels rose during the 20lh century and are expected to continue to rise at an
increasing rate. Tropical storms are projected to become more intense as well.
Trends in Relative Sea Level Rise Along U.S. Coasts, 1958 to 2008
Relative sea level change (inches):
-7.99 -5.99 -3.99 -1.99
<-8 to-6 to-4 to-2 toO
II ( 0.01 2.01 4.01 6.01 >8
1 to2 to4 to6 to8
Source: National Oceanic and Atmospheric Administration. 2009. Update to data
available at http://tidesandcurrents.noaa.gov/publications/techrpt36.pdf
The U.S. East Coast and Gulf Coast are particularly vulnerable to sea level rise and
storm surges because the land is relatively low and also subsiding in many places.
Alaska is also at risk, with extreme changes in local sea level rise caused by a
combination of geologic and climate-related factors.
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Change in Plant Hardiness Zones,
1990 to 2006
1990
2006
10
Source: Arbor Day Foundation. 2006. www.arborday.org/media/map_change.cfm
Plant hardiness zones are regional designations that help farmers
and gardeners determine which plant species are expected to
survive a typical winter. Locations are assigned a numbered plant
hardiness zone based on an average of the lowest temperatures
recorded each winter. This figure depicts plant hardiness zones in
the lower 48 states in 1990 and 2006.
Food Production
A changing climate will affect farming, ranching, and fishing.
Some of these effects will be positive, and others will be negative,
depending on the region and the type of food being produced.
Higher temperatures will mean a longer growing season in
cooer regions. This could allow farmers to diversify crops or have
multiple harvests from the same plot. In warmer regions, however,
temperatures might become too high for certain crops to grow. In
addition to rising temperatures, changing precipitation patterns and
extreme weather events will also affect crops.
High temperatures and extreme weather can also stress livestock,
causing some animals to become sick or die. Fisheries could see
losses as well, particularly for fish that require cold or cool water,
such as salmon.
Energy Use and Supply
Climate change is likely to affect the amount of energy used to heat
buildings in the winter, as well as the amount of energy used to cool
them in the summer. As average temperatures rise, some areas will
require more energy to cool buildings but less energy to heat them.
Increased demand for air conditioning could stress the capacity of
power plants, transmission grids, and distribution systems, causing
brownouts or power outages during heat waves. Because power
plants also use large amounts of water, facilities located in areas
where water supplies are expected to be scarce could experience
operational difficulties.
Other Effects
Changing climate conditions can also lead to other economic costs.
For example, heat waves, decreased snowfall, and changing wildlife
habitats could adversely affect some types of sporting and outdoor
activities, including hunting, fishing, skiing, camping, and tourism.
Larger and more intense storms, wildfires, and floods could damage
infrastructure such as roads, railways, airports, power grids, water
supply systems, and sewers, resulting in expensive repair costs.
Although climate change will affect all nations, some will feel the
effects more acutely than others. Developing countries tend to have
fewer resources, and thus extreme weather events, food shortages,
and water shortages can lead to socia disruption, instability, and
conflict in these countries. In an increasingly interdependent world,
environmental changes in other countries can pose challenges for
U.S. national security as well.
Events such as Hurricane Katrina show that the United States and
its citizens can feel the effects of extreme weather events. In areas
where climate change leads to increased extreme weather events,
like heat or storms, some people—including the poor, the elderly,
and the disabled—could be disproportionately affected.
For More Information
For detailed information about greenhouse gas emissions,
the effects of climate change, EPA efforts underway,
and tips on what you can do, visit EPA's Climate Change
Web site at www.epa.gov/climatechange.
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