How rising temperatures increase the risk of drought
NASA projects an 80% chance of a megadrought hitting the U.S. Central Plains and Southwest between 2050 to 2099, if climate change remains unaddressed.(1) The ‘megadroughts’ are expected to persist for 30 years, about three times longer than the infamous “Dust Bowl” in the 1930s and the current drought in California. According to NASA, these droughts have little precedent. Droughts of this scale have not been seen in over 1,000 years.(2)
“These droughts really represent events that no one in the history of the United States have had to deal with.”
-Ben Cook, NASA scientist, Feb 2015
How rising temperatures increase the risk of drought
Climate change and warmer temperatures generally rob more moisture from soil and plants. Water evaporates into the air and eventually falls back down as precipitation. Thanks to wind, though, that water doesn’t always fall back in the same place.(3),(4),(5) The areas that lose moisture do not always get it back.(6) Put simply, warmer temperatures escalate the chance that temporary dry spells turn into long-lasting droughts.(7)
Rising temperatures cause both drought and flood
You may have heard that climate change can also lead to flooding. It might seem odd that rising temperatures could cause floods in some areas and drought in others, but that’s one of the strange effects of climate change.
It is widely agreed that warmer temperatures create conditions for prolonged droughts but only a few droughts in recent history have been directly linked to climate change.(8),(9) The main reason for this is that the effects of climate change have been moderate thus far, but are expected to become worse in the future.(10)
“Human caused climate change [is now] a major factor in more frequent Mediterranean droughts.”
– National Oceanic and Atmospheric Administration, October 2011
Drought threatens our electricity system
It may surprise you, but one of the largest users of water is the electricity sector. 38 percent of U.S. freshwater use is used by conventional power plants (nuclear, natural gas, coal), according to the US Geological Survey.(11) A standard coal plant uses over 3,300 gallons of water a second.(12) For a sense of scale, one plant would use all the water in an Olympic-sized pool in less than two and a half minutes.(13) What’s remarkable is that the 45 percent does not even account for hydropower plants, the ones that make energy using dams such as the Hoover Dam.
“Thermoelectric power generation facilities are at risk from decreasing water availability and increasing ambient air and water temperatures.”
– U.S. Department of Energy, July 2013
Drought leads to huge losses for corn farmers
Our electricity isn’t the only thing at stake. Droughts generate more risks and uncertainties for farmers. According to the U.S. National Academy of Sciences, U.S. corn yields are expected to decline 5 to 15% per each degree of warming.(14) The 2012 drought – the worst since the 1950s – affected 80 percent of all U.S. agricultural land and 85 percent of corn-growing land.(15) Corn production fell 19.8 percent and insurance payments from the failed crops hit a record $12.3 billion.(16)
“My farm yielded 223 bushels last year… right now, it looks like zero… this drought is unreal, absolutely unreal.”
-Harvey Kopp, Wisconsin farmer, July 2012
SOURCES
- NASA: NASA Study Finds Carbon Emissions Could Dramatically Increase Risk of US Megadroughts
- NASA: NASA Study Finds Carbon Emissions Could Dramatically Increase Risk of US Megadroughts
- National Park Service: Climate Change Impacts of Warming on the Great Plains
- NOAA: Future Drought
- UCAR: Climate Change May Threaten Much of the Globe Within Decades
- ClimateCentral: Climate Change has Intensified the Global Water Cycle
- ClimateCentral: Many Uncertainties in Climate Change’s Role in Drought
- NOAA: Mediterranean Drought
- Stanford University: California Drought
- ClimateCentral: Many Uncertainties in Climate Change’s Role in Drought
- US Geological Survey
- Department of Energy
- Bloomberg
- S. National Academy of Sciences
- Energy Information Administration
- Wisconsin State Journal
GRAPHIC SOURCES
- Corn Growing Area Affected by Drought – USDA via Energy Information Agency
- Warmer Temperature Increases Risks – Columbia University