After three years of belittling or suppressing science, the Bush administration appears willing to concede that humans and their industrial activity have been largely responsible for the recent warming of the earth's atmosphere. This tardy acceptance of what mainstream scientists have been saying for years does not mean that the administration is prepared to deal seriously with the problem - by, for instance, supporting mandatory caps on emissions of carbon dioxide. But at least nobody is trying to hide the evidence.

The administration's views are contained in a report to Congress accompanied by a letter signed by the secretaries of energy and commerce and the president's science adviser. It asserts that natural causes cannot explain significant warming since 1970 and says that man-made emissions from smokestacks and tailpipes are the likely cause.

White House officials, who did not go out of their way to publicize the report, clearly do not mean it to be interpreted as a campaign-year change in President Bush's position on global warming or as a precursor to more aggressive legislative and administrative measures. But they did not brush it off, as happened in 2002 when Mr. Bush dismissed a serious internal study written by his own experts. Nor did they attempt to suppress it, as happened later that year with a report on air pollution from the Environmental Protection Agency.

So this is progress, of a sort. But it won't mean much unless Mr. Bush gets serious about remedies. His program of research and voluntary initiatives has generated modest enthusiasm in industry but inspires little confidence that the warming trends will be arrested, much less reversed, in the foreseeable future. Meanwhile, there are several initiatives awaiting attention on Capitol Hill that could begin to restrict greenhouse gas emissions. But they have no chance of approval unless Mr. Bush gives the nod to the Republican leadership.