Researchers Propose Adapting Definition of Drought to Match New Climate Realities

As record-breaking drought conditions persist in the western U.S., climate researchers are reconsidering the definition and implications of droughts as climate change continues to change long-term weather patterns. Indeed, the western U.S. has been experiencing a so-called megadrought since the turn of the twenty-first century and based on modern drought definitions researchers do not believe conditions will reset back to its previous ‘normal’ state. Therefore, scientists propose moving away from fixed definitions and allow for a greater nuanced understanding of drought and pluvial (abnormally wet events). “Our idea of normal is, in a sense, meaningless when ‘normal’ is continuously changing,” said Samantha Stevenson, an assistant professor in the Bren School of Environmental Science & Management.

To understand future drought conditions, Stevenson and her team attempted to predict future precipitation and soil moisture levels. They utilized a new collection of climate models from multiple research institutions for their study. The results indicate some regions in the world will remain in permanent drought and average soil moisture in many areas will continue to decline. Precipitation trends will become more extreme. The researchers believe analyzing trends in rainfall and soil moisture can help with sustainable water management going forward.  

“When we talk about being in a drought, the presumption is that eventually the drought will end, and conditions will return to normal,” Stevenson said. “But if we’re never returning to normal, then we need to adapt all of the ways that we manage water with the expectation that normal will continually be drier and drier every year.” Read more at UC Santa Barbara or access the full study here.