Climate Change Altering Droughts, Impacts Across U.S.. As a major drought devastated the West and Midwest beginning in 2012, farmers racked up billions of dollars in crop losses and water managers grappled with possible water shortages for millions of people as reservoirs dried up in the heat.
“A huge chunk of the country is in drought (during that period) and other chunks are really wet.” Warmer temperatures over the past 30 years and more frequent regional dry spells since 1998 are changing the water cycle, posing challenges for urban and agricultural areas throughout the country.
2012 was a critical year for drought in the U.S. Several ongoing regional droughts “merged” to create a massive nationwide drought leaving more than 60 percent of the country suffering severe levels of drought or worse.
Research shows that when dry spells occur, climate change is likely to make them drier than they would otherwise be because warmer temperatures increase evaporation.
A Climate Central analysis shows that since 1949, 68 percent of weather stations between 2,000 feet and 5,000 feet in elevation in 42 states have seen a lower percentage of winter precipitation falling as snow.
Heim’s study shows that one of the unusual characteristics of the most recent drought compared to those in the 20th century is that, on a national scale, the drought’s driest seasons were in the winter and spring.
Cook said that the 2012 “merger” of regional droughts is unusual because different regions of the country typically see their wet and dry seasons at different times of year.
California, for example, receives nearly all its precipitation during the winter, while the Central Plains see their wettest months during spring and early summer.
“Most droughts are a bit quirky in their character, and all droughts impact a different society and economy than their predecessors making each drought and its lessons substantially unique,” Lund said.
“Still, it is very likely that higher temperatures will worsen the severity of droughts.” Comments [+] View our comment guidelines.