Nature and Sources:
The Earth's climate is fueled by the Sun. Most of the Sun's energy, called
solar radiation, is absorbed by the Earth, but some is reflected back into
space. A natural layer of atmospheric gases absorbs a portion of this reflected
solar radiation, eventually releasing some of it into space, but forcing
much of it back to Earth. There it warms the Earth's surface creating what
is known as the natural "greenhouse effect," as illustrated in the diagram
below.
Without the natural greenhouse effect, the Earth's average temperature
would be much colder, and the planet would be covered with ice.
Recent scientific evidence shows that the greenhouse effect is being
increased by release of certain gases to the atmosphere that cause the
Earth's temperature to rise. This is called "global warming." Carbon dioxide
(CO2) accounts for about 85 percent of greenhouse gases released in the
U.S. CO2 emissions are largely due to the combustion of fossil fuels in
electric power generation. Methane (CH4) emissions, which result from agricultural
activities, landfills, and other sources, are the second largest contributor
to greenhouse gases in the U.S.
Industrial applications such as foam production, refrigeration, dry
cleaning, chemical manufacturing, and semiconductor manufacturing produce
other greenhouse gas emissions such as hydrofluorocarbons (HFCs). Smelting
of aluminum produces another greenhouse gas called perfluorinated compounds
(PFCs). Emissions of NOx and VOC from automobile exhaust and industrial
processes contribute to the formation of ground-level ozone or smog, also
a greenhouse gas.
Health and Environmental Effects:
Greenhouse gas emissions could cause a 1.8 to 6.3° Fahrenheit rise
in temperature during the next century, if atmospheric levels are not reduced.
Although this change may appear small, it could produce extreme weather
events, such as droughts and floods; threaten coastal resources and wetlands
by raising sea level; and increase the risk of certain diseases by producing
new breeding sites for pests and pathogens. Agricultural regions and woodlands
are also susceptible to changes in climate that could result in increased
insect populations and plant disease. This degradation of natural ecosystems
could lead to reduced biological diversity.
International Developments:
Over 150 world leaders have responded to the early warnings of climate
change. In 1988, the Intergovernmental Panel on Climate Change (IPCC) was
formed, and in 1992, these 150 countries signed a treaty known as the "Framework
Convention on Climate Change" (FCCC) to stabilize atmospheric greenhouse
gases. Early indications suggest that most countries are not on track to
meet the year 2000 target for reducing emissions of greenhouse gases, and
further, that holding emissions at 1990 levels will not prevent or solve
the problem. In 1997, the FCCC will meet in Japan, where agreement may
be reached on a legally binding international pact to prevent or reduce
the risk of climate change.
U.S. Programs to Mitigate Climate Change:
The United States adopted a Climate Change Action Plan in 1993 to reduce
greenhouse gas emissions. Hundreds of companies and nonprofit organizations
are working together to effectively reduce their emissions. The Plan involves
50 programs implemented by EPA, the Department of Energy, the Department
of Agriculture, and other Government agencies. EPA's voluntary pollution
prevention programs seek to prevent greenhouse gas emissions through partnerships
with business, government, and other groups by stimulating investments
in energy-efficient technology and practices. Combined, EPA's voluntary
pollution prevention programs to reduce greenhouse gas emissions have over
2,000 partners. Since 1992, participants in these programs have prevented
the release of over 2.5 million tons of greenhouse gas emissions.
EPA's voluntary pollution
prevention programs are reducing greenhouse gas emissions through partnerships
with industry and others.
EPA Voluntary Programs to Reduce Greenhouse Gas Emissions |
Objective |
Green Lights / Energy
Star Buildings Program |
Energy-efficient lighting, heating, air conditioning, and ventilation
systems |
Energy Star Programs |
Commercial and residential energy-efficient products and effective
product labeling |
Natural Gas Star, AgStar, and Landfill Methane
Outreach Programs |
Cost-effective reduction of methane emissions |
Voluntary Aluminum Industrial Partnership |
Reduction of perfluorinated compound emissions |
Climate Wise Program |
Company-specific emissions reduction plans |
|