A new study funded by the National Aeronautics and Space
Administration (NASA) predicts that the world’s climate will warm over
the next 50 years regardless of whether nations soon curb their
greenhouse gas emissions, such as carbon dioxide (CO2) from the
burning of fossil fuels.

A September 19 release says the study was based on the findings of a
new computer climate model that used data from the last 50 years to
project warming over the next 50 years. The research was a
collaborative effort of 19 institutions, including universities,
federal agencies and private industry.

The study found that global temperatures may increase by 1 to 2
degrees Celsius if no reductions in greenhouse gas emissions are made
and they continue to increase at the current rate. But if the growth
rate of carbon dioxide does not exceed its current rate and if the
growth of true air pollutants – substances that are harmful to human
health – is reversed, temperatures may rise by only 0.75 degrees

“Some continued global warming will occur … even if the greenhouse
gases in the air do not increase further, but the warming could be
much less than the worse case scenarios,” said Jim Hansen, the study’s
lead researcher at NASA’s Goddard Institute for Space Studies.

Hansen cautioned that the “alternative” scenario, in which air
pollution is decreased and fossil fuel CO2 emissions are stabilized,
will not be easy to achieve. It requires that the world begin to
reverse emissions of air pollutants such as soot, methane and carbon

The study said achievement of stable CO2 emissions is likely to
require some combination of increased energy efficiencies, a growing
role for renewable energies, capture and sequestration of CO2
emissions, and/or increased use of nuclear power. It adds that all
these possibilities are being addressed by the administration’s
National Climate Change Technology Initiative.

Researchers said the computer climate model, called GISS SI2000, also
provided a convincing demonstration that the global temperature change
of the past half century was a response to the release of greenhouse
gases, such as carbon dioxide and methane, which trap the Earth’s heat
radiation as a blanket traps body heat.