Part A. Reading Comprehension.
Read the following text:
Arctic Sea Ice Melting Faster
Climate scientists may have significantly underestimated the power of global warming from human-generated heat-trapping gases to shrink the cap of sea ice floating on the Arctic Ocean. A new study concluded that an open-water Arctic in summers could be more likely in this century than had been estimated in the latest international review of climate research released in February.
“There are huge changes going on,” said Julienne Stroeve, author of this new study. “Just with warm waters entering the Arctic, combined with warming air temperatures, this is causing destruction on the sea ice.”
She also concluded that if emissions of heat-trapping gases like carbon dioxide were not significantly reduced, the region could end up with no floating ice in summers sometime between 2050 and the early decades of the next century.
For the new study, Dr. Stroeve reviewed nearly six decades of measurements by ships, airplanes and satellites estimating the maximum and minimum area of Arctic sea ice, which typically expands most in March and shrinks most in September.
With an expert from the National Center for Atmospheric Research, they then compared the observed trends with the projections made for the United Nations Intergovernmental Panel on Climate Change, using the world’s most advanced computer models of climate.
Dr. Stroeve found that since 1953 the area of sea ice in September has declined at an average rate of 7.8 per cent per decade. Computer climate simulations of the same period had an average rate of ice loss of 2.5 per cent per decade.
ANDREW C. REVKIN
May 1, 2007
The New York Times