The Intergovernmental Panel on Climate Change (IPCC)
published a series of reports in 2007 that set forth conclusions
about the
causes and effects of global warming as well as the costs and benefits of
solving the problem.
The reports, which drew on the work of more than 2,500 of the world’s
leading climate scientists and were endorsed by 130 nations, confirmed the
consensus of scientific opinion on the key questions related to global warming.
Taken together, the reports are intended to help policymakers worldwide make
informed decisions and develop effective strategies to reduce
greenhouse gas
emissions and control global warming.
What is the Purpose of the IPCC?
The IPCC was established in 1988 by the World Meteorological Organization (WMO)
and the United Nations Environment Programme (UNEP) to provide a comprehensive
and objective assessment of scientific, technical and socio-economic
information that could lead to a better understanding of human-induced climate
change, its potential impacts, and the options for adaptation and mitigation.
e call the result global warming, but it is causing a set of changes to the
Earth''s climate, or long-term weather patterns, that varies from place to
place. As the Earth spins each day, the new heat swirls with it, picking up
moisture over the oceans, rising here, settling there. It''s changing the
rhythms of climate that all living things have come to rely upon.
What will we do to slow this warming? How will we cope with the changes
we''ve already set into motion? While we struggle to figure it all out, the face
of the Earth as we know it—coasts, forests, farms and snow-capped
mountains—hangs in the balance.
e call the result global warming, but it is causing a set of changes to the
Earth''s climate, or long-term weather patterns, that varies from place to
place. As the Earth spins each day, the new heat swirls with it, picking up
moisture over the oceans, rising here, settling there. It''s changing the
rhythms of climate that all living things have come to rely upon.
What will we do to slow this warming? How will we cope with the changes
we''ve already set into motion? While we struggle to figure it all out, the face
of the Earth as we know it—coasts, forests, farms and snow-capped mountains—hangs
in the balance.
Greenhouse effect
The "greenhouse effect" is the warming that happens when certain
gases in Earth''s
atmosphere trap heat. These gases let in light but keep heat
from escaping, like the glass walls of a greenhouse.
First, sunlight shines onto the Earth''s surface, where it is absorbed and
then radiates back into the atmosphere as heat. In the atmosphere, “greenhouse”
gases trap some of this heat, and the rest escapes into space. The more
greenhouse gases are in the atmosphere, the more heat gets trapped.
Scientists have known about the greenhouse effect since 1824, when Joseph
Fourier calculated that the Earth would be much colder if it had no atmosphere.
This greenhouse effect is what keeps the Earth''s climate livable. Without it,
the Earth''s surface would be an average of about 60 degrees Fahrenheit cooler.
In 1895, the Swedish chemist Svante Arrhenius discovered that humans could
enhance the greenhouse effect by making carbon dioxide, a greenhouse gas. He
kicked off 100 years of climate research that has given us a sophisticated
understanding of global warming.