Federal report links climate change, extreme weather

A government report on climate change released Friday said global warming is contributing to extreme weather in the United States. Outside scientists and officials from 13 federal agencies wrote the report, which is mandated by law every four years. This year’s analysis said extreme weather events “have already become more frequent, intense, widespread or of long duration.” The report warned that the negative effects of climate change could cost the U.S. economy hundreds of billions of dollars. But the White House said in a statement that the authors based their conclusion on an extreme model of climate change, and the next report would be more balanced.