Climate change making megadroughts much worse, says study

Severe drought conditions have helped fuel the Los Angeles wildfires. But a new study, released on Thursday in the journal Science, comes with a warning: climate change is making catastrophic, multi-year “megadroughts” much worse around the world.

Droughts are relative – a drought in normally rainy Seattle, for example, might register as an unusually wet period in a drier climate such as Phoenix, Arizona. But they can throw ecosystems out of whack, sometimes in dangerous ways.

“That’s what we see right now in California,” said Dirk Nikolaus Karger, a senior researcher at Swiss Federal Institute WSL and a paper author. “Over time, the vegetation dries out, and we have increased fire frequency, and houses burn down. In other areas, we will have agricultural failures.”

The fires in California are being driven by only eight months with little rainfall. While climate change is contributing to more erratic precipitation in the western US, the new paper takes a global view of droughts that last years.

The researchers were motivated to do so after Karger and co-author Francesca Pellicciotti spent time in Chile, which is in the midst of a drought that began in 2010.

“The consequences were devastating, from ecosystems to agriculture,” said Pellicciotti, a professor at the Institute of Science and Technology Austria.