February 12th, 2015 by Derek Markham
Like many who live in the US Southwest, I’ve made my peace with the seemingly ever-present drought conditions here, and it’s somewhat like a sick joke to imagine that these desert lands could be any more arid, but if the predictions from a newly released study prove out, it could get a whole lot drier down here.
The authors of the study, which is an analysis of 17 different projections of 21st century climate modeling, along with data about droughts over the past thousand years, go so far as to say that future drought risk in the American Southwest and Great Plains is “unprecedented,” and we could be dealing with the worst drought in 1000 years.
The analysis, titled Unprecedented 21st century drought risk in the American Southwest and Central Plains and published at Science Advances, also took into consideration the increasingly warmer temperatures in those regions, which in turn drives evaporation rates higher.
The lead author of the study, Benjamin Cook, a research scientist at the NASA Goddard Institute for Space Studies, suggests that we need to think about dealing with “a much drier future” in the western US, and that future droughts will present “a major adaptation challenge” for those regions.
“Our results point to a remarkably drier future that falls far outside the contemporary experience of natural and human systems in Western North America, conditions that may present a substantial challenge to adaptation.”
Some of the data came from tree rings covering the years 1000-2005, which showed evidence of these megadroughts affecting the Great Plains and Southwest regions in the past, and lasting for decades, but those droughts may be child’s play when compared to future megadroughts. According to another of the authors, Toby Ault of Cornell University, there is an 80% chance that as soon as 2050, those regions will experience a megadrought that could last 35 or more years.
“Here, we have demonstrated that the mean state of drought in the late 21st century over the Central Plains and Southwest will likely exceed even the most severe megadrought periods of the Medieval era in both high and moderate future emissions scenarios, representing an unprecedented fundamental climate shift with respect to the last millennium.”
Our increasing carbon emissions are continuing to drive the climate change engine along a path that, when coupled with an already high drought risk and increasing pressure on water supplies, will affect everything from agriculture to energy production, and a megadrought could be the proverbial last straw for the west.
“Combined with the likelihood of a much drier future and increased demand, the loss of groundwater and higher temperatures will likely exacerbate the impacts of future droughts, presenting a major adaptation challenge for managing ecological and anthropogenic water needs in the region.”
The full research article is at Science Advances.
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