Brace yourself. That's the underlying message in a new report from the federal government, which predicts more extreme weather events in North America as a result of human-caused global warming. According to the report, in the coming decades we can expect more droughts, heavy rainfall, heat waves, and hurricanes; these weather events will be both more commonplace and more intense. The report, from the Bush administration's U.S. Climate Change Science Program, says these changes are already apparent.