Bush Study Shows Global Warming Caused by Humans

Finally, agreement: Global warming is real, and "part of what has happened over the last 50 years has clearly been caused by humans."

The downside? Even with new energy sources it will be "impossible to slow warming noticeably in the coming decades," according to Dr. John R. Christy. He says countries must adapt to warming.


Federal Study Finds Accord on Warming

A scientific study commissioned by the Bush administration concluded yesterday that the lower atmosphere was indeed growing warmer and that there was "clear evidence of human influences on the climate system." ...The finding eliminates a significant area of uncertainty in the debate over global warming, one that the administration has long cited as a rationale for proceeding cautiously on what it says would be costly limits on emissions of heat-trapping gases.

The new study found that "there is no longer a discrepancy in the rate of global average temperature increase for the surface compared with higher levels in the atmosphere," in the words of a news release issued by the Commerce Department and approved by the White House. The report was published yesterday online at climatescience.gov. ...The report's authors all agreed that their review of the data showed that the atmosphere was, in fact, warming in ways that generally meshed with computer simulations. The study said that the only factor that could explain the measured warming of Earth's average temperature over the last 50 years was the buildup heat-trapping gases, which are mainly emitted by burning coal and oil.

John R. Christy, an author of the new report whose analysis of satellite temperature records long showed little warming above Earth's surface, said he endorsed the conclusion that "part of what has happened over the last 50 years has clearly been caused by humans." ...Dr. Christy also said that even given what the models projected, it would be impossible to slow warming noticeably in the coming decades. Countries would be wise to seek ways to adapt to warming, he added, even as they seek new sources of energy that do not emit heat-trapping gases.