The term "weather whiplash" is being invoked to describe the drought-flood cycles beginning to take over the Mississippi and Missouri rivers.
The cause of the maddening weather extremes and their huge and varied consequences is none other than climate change, according to a new report by the climate science communication organization Climate Nexus, and backed by climate researchers.
"In some parts of the world, including the 1.2 million square miles comprising the Mississippi River Basin, climate change can manifest as alternating periods of 'feast or famine' -- wide swings of extremes such as flooding and drought," the report reads.
The term "weather whiplash" was first invoked to describe this effect by science writer Andrew Freedman in 2009. But now climate scientists are using the term, and pointing to the current floods, in the Midwest as the classic case.
"I'm using it now to describe the longer term kind of flooding-drying cycles," said meteorologist Jeff Masters, co-founder and director meteorology at the Weather Underground. "It's pretty amazing. It used to be only one in three years were flood years. Now it's almost every year."
The whiplash has become especially painful in river towns where just a few months ago dredging was needed to keep goods afloat and keep communities alive. Now sandbags are the only thing holding back the rivers from flooding the very same towns.
The physical reason for the extremes is that as the atmosphere gets hotter, it holds more water and so is capable of generating more extreme rainfall events, Masters explained. On the other hand, it’s harder to separate water from warmer air, which means drier seasons get drier.
We do expect to see both drought and floods in a hotter atmosphere Masters told Discovery News. "The models say the wet areas are going to get wetter and dry areas drier."
And since climate change is global, the whiplash isn’t only happening in North America.
"In the U.S. of course, it is going from floods in 2011 (Missouri through Ohio River Valley to New England, flooding Mississippi and Missouri) to widespread drought in 2012 and back to floods in 2013," said climate researcher Kevin Trenberth of the National Center for Atmospheric Research. "But it's much worse in Australia: a nine-year drought then floods mid-2010 to mid-2011 and then back to drought and record heat in Jan this year."
Nor can the pattern be expected to get any better, say climate scientists.
"Society and its infrastructure were designed for the climate of the past, not for the rapidly changing climate of the present or the future," reads the Climate Nexus report, quoting from the 2013 National Climate Assessment. "Climate change, once considered an issue for a distance future, has moved firmly into the present. Impacts related to climate change are already evident in many sectors and are expected to become increasingly challenging across the nation throughout this century and beyond."