How has the concurrence of drought and heatwaves in the U.S. changed over time?

  • 9 September 2015
  • Number of views: 2182

Extreme climate events, such as droughts and heatwaves, are one of the biggest challenges facing our society, significantly impacting human health, ecosystems, security, and our economy. Concurrent extreme events can potentially exacerbate the severity and impacts of each individual event, but most studies of extremes have focused on a single climatic event, possibly underestimating net impacts. It is important to evaluate the changes and potential impacts of concurrent extremes in order to effectively prepare for the negative effects of climate change.

Research by Omid Mazdiyasni and Amir AghaKouchak (University of California, Irvine), funded by CPO’s Modeling, Analysis, Predictions, and Projections program, was recently published in Proceedings of the National Academy of Sciences (PNAS). This study applied the Cramer-von Mises change point detection test statistic approach, a technique common to economics and finance, to analyze changes in concurrent meteorological droughts and heatwaves from 1960-2010. While the authors found no significant changes over time in meteorological drought, the concurrence of droughts and heatwaves have significantly increased specifically in the south, southeast, and western U.S. 

To view the paper, go to:




Americans’ health, security and economic wellbeing are tied to climate and weather. Every day, we see communities grappling with environmental challenges due to unusual or extreme events related to climate and weather. In 2017, the United States experienced a record-tying 16 climate- and weather-related disasters where overall costs reached or exceeded $1 billion. Combined, these events claimed 362 lives, and had significant economic effects on the areas impacted, costing more than $306 billion. Businesses, policy leaders, resource managers and citizens are increasingly asking for information to help them address such challenges.


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