Climate's role in US droughts is under scrutiny

http://www.newscientist.com/article/mg21829134.600-climates-role-in-us-droughts-is-under-scrutiny.html

CAN the extreme drought that devastated crops across the US Midwest in 2012 be blamed on global warming? Probably not, according to a report from the US National Oceanic and Atmospheric Administration (NOAA). But the conclusion has been met with stinging criticism from another leading climate scientist.

The controversy highlights the need for better methods to assess if and how extreme weather events are linked to climate change.

Martin Hoerling of NOAA's Earth System Research Laboratory in Boulder, Colorado, and colleagues investigated why seasonal forecasts failed to predictlast year's drought. They also ran computer simulations to see if a similar drought would have occurred in the absence of human greenhouse gas emissions.

The team did n