Unprecedented droughts lasting several decades are expected to plague the Southwest and Central Plains during the last half of this century, according to a new report by authors from Columbia University, Cornell University and the NASA Goddard Institute. These future “megadroughts,” as scientists are calling them, would be more severe than any dry period experienced in North America within the past 1,000 years.
The study’s authors, who published their findings in the journal Science Advances in February, paired historical data of past drought trends with the most advanced climate models to make their predictions. “In both the Southwest and Central Plains, we’re talking about risk levels of 80 percent that a 35-year-long drought will occur by the end of the century if climate change goes unmitigated,” says study co-author Toby Ault, a professor of earth and atmospheric sciences at Cornell.
While droughts are a natural part of the planet’s climate cycles, research has shown that higher temperatures resulting from human-produced greenhouse gas emissions will exacerbate natural dry spells by increasing evaporation rates during the same time period that precipitation will drop. Many scientists characterize regional climate change impacts with the generalization, “Wet places will get wetter and dry places will get drier.” Recent studies affirm this prediction — not only for the parched Plains and Southwest, but also for the relatively wet eastern half of the country, where precipitation is projected to increase.
Groundwater used for irrigation is already being depleted at an unsustainable rate in many agricultural regions. A decades-long drought in these areas would spell devastation for the farmers who produce the amber grains of the Central Plains, and for the industries and exporters that rely on U.S. wheat, corn and soybeans. We don’t have to follow this path, however. If we cut our carbon emissions, the study’s authors say, we can mitigate climate change and significantly reduce drought risk, especially for the Central Plains. Read the full report online.
Kale Roberts is the Blogging Coordinator and a former editor for MOTHER EARTH NEWS. He is currently a Rachel Carson Scholar at the Bard Center for Environmental Policy. His interests include renewable energy, climate finance, and sustainable rural development. You can find him on Google+.