sciencehabit writes "2012 was a year of extreme weather: Superstorm Sandy, drought and heat waves in the United States; record rainfall in the United Kingdom; unusually heavy rains in Kenya, Somalia, Japan, and Australia; drought in Spain; floods in China. One of the first questions asked in the wake of such extreme weather is: 'Could this due to climate change?' In a report (huge PDF) published online today, NOAA scientists tackled this question head-on. The overall message of the report: It varies. 'About half of the events reveal compelling evidence that human-caused change was a [contributing] factor,' said NOAA National Climatic Data Center Director Thomas Karl. In addition, climate scientist Peter Stott of the U.K. Met Office noted that these studies show that in many cases, human influence on climate has increased the risks associated with extreme events."