Scientists Detail Climate Changes

By James Kanter and Andrew C. Revkin

The New York Times
Saturday 07 April 2007

Poles to Tropics

BRUSSELS, April 6 — From the poles to the tropics, the earth’s climate and ecosystems are already being shaped by the atmospheric buildup of greenhouse gases and face inevitable, possibly profound, alteration, the world’s leading scientific panel on climate change said Friday.

In its most detailed portrait of the effects of climate change driven by human activities, the panel predicted widening droughts in southern Europe and the Middle East, sub-Saharan Africa, the American Southwest and Mexico, and flooding that could imperil low-lying islands and the crowded river deltas of southern Asia. It stressed that many of the regions facing the greatest risks were among the world’s poorest.

And it said that while limits on smokestack and tailpipe emissions could lower the long-term risks, vulnerable regions must adjust promptly to shifting weather patterns, climatic and coastal hazards, and rising seas.

Without such adaptations, it said, a rise of 3 to 5 degrees Fahrenheit over the next century could lead to the inundation of coasts and islands inhabited by hundreds of millions of people. But if steady investments are made in seawalls and other coastal protections, vulnerability could be sharply reduced.

The group, the United Nations’ Intergovernmental Panel on Climate Change, also noted that the climate shifts would benefit some regions — leading to more rainfall and longer growing seasons in high latitudes, open Arctic seaways and fewer deaths from the cold.

The 1,572-page report, finished here on Friday, was prepared by more than 200 scientists, and a 21-page summary was endorsed by officials from more than 120 countries, including the United States.