10 Things That Don’t Disprove Global Warming

There's No Proof Global Warming Causes Drought
A seccret service agent looks over a farm field as U.S. President Barack Obama speaks to the media on California's drought situation in early 2014. Wally SKALIJ/AFP/Getty Images

When President Barack Obama promised to provide federal aid to drought-stricken California in February 2014, he and aides said the state's water problems might indicate what's in store for the rest of the nation as global warming intensifies [source: Gillis]. That immediately resulted in a fusillade of criticism from climate change skeptics, who attacked the White House for going further than scientific knowledge justified, and cited that overreach to discredit the notion of climate change itself.

To an extent, the critics had a point, since Columbia University climate scientist Richard Seager told The New York Times that the severe dry spell in California was probably just an extreme swing of the state's natural weather variability.

But it is also true that droughts in some areas are a predicted impact of global warming, even as climate shifts may cause other areas to become wetter [source: : Gillis]. A study published in Nature Climate Change in 2013, for example, predicted that global warming may lead to "severe and widespread droughts in the next 30-90 years" [source: Dai].