During his 7 1/2 years in office, President Bush has declared 422 major disasters — severe storms, tornadoes, wildfires and floods — or more than one a week. That is 11 percent more than President Clinton's disaster declarations and 130 percent more than President Reagan's during their full two terms in office.

All those natural disasters translate into more federal government spending. Under Bush, the government has committed to spend $87 billion in disaster relief funds to help states and localities clean up after floods, fires and storms, compared with Clinton's nearly $29 billion. Even after adjusting for inflation, the Bush administration has spent 2.5 times more than the Clinton administration on disaster relief.

Of the $87 billion obligated under the Bush administration, $36 billion is from cleaning up after Hurricane Katrina in 2005, the costliest natural disaster on U.S. soil. Another $4 billion went toward the aftermath of Hurricane Rita, which also occurred in 2005. Even excluding that $40 billion commitment, Bush outspent each of his predecessors on disaster aid. The figures do not include disaster loans.

One controversial explanation for why the country has been more disaster prone under Bush is global warming. Most scientists agree that greenhouse gases are heating up the earth's atmosphere but most generally agree that no single weather-related disaster can be attributed to climate change with certainty.

While most experts say they cannot correlate the rise in the number of disaster declarations with global warming, they accept that the trend will continue, and that that means a growing cache of federal tax dollars will need to be diverted to help states cope. Others offer alternative explanations, including that Bush's disaster relief decisions have been politically motivated, either to help Republican governors or to shield him from the kind of criticism he received for his handling of Hurricane Katrina.

But in Bush's case, the numbers do not support this view. In each year after Hurricane Katrina, the White House did not declare as many disasters as it did in 2004.

This summer has seen a spike in spending because of severe floods in the Midwest and other states. Michigan, Oklahoma, Missouri and South Dakota have also received assistance because of severe storms and floods. The Bush administration has committed $6.6 billion in federal funds through June and, if that pace continues, the total for 2008 could be close to $9 billion, only the fifth-highest year in disaster spending under Bush.