Earth’s Climate Warming Abruptly, Scientist Says:

The warming around Earth’s tropical belt is a signal suggesting that the "climate system has exceeded a critical threshold," which has sent tropical-zone glaciers in full retreat and will melt them completely "in the near future," said Lonnie G. Thompson, a scientist who for 23 years has been taking core samples from the ancient ice of glaciers.

Thompson, writing with eight other researchers in an article published Monday in the Proceedings of the National Academy of Sciences, said the ice samples show that the climate can and did cool quickly, and that a similarly abrupt warming change started about 50 years ago. Humans may not have the luxury of adapting to slow changes, he suggests.