Rapid intensification of the emerging southwestern North American megadrought in 2020-2021

Southwestern North America has been experiencing lower than average precipitation and higher temperatures since 2000. This emerging megadrought, spanning 2000-2021, has been the driest 22-year period since the year 800 and 19% of the drought severity in 2021 can be attributed to climate change. A previous reconstruction back to 800 ce indicated that the 2000-2018 soil moisture deficit in southwestern North America was exceeded during one megadrought in the late-1500s. Here, we show that after exceptional drought severity in 2021, similar to 19% of which is attributable to anthropogenic climate trends, 2000-2021 was the driest 22-yr period since at least 800. This drought will very likely persist through 2022, matching the duration of the late-1500s megadrought.

Automated summary

Southwestern North America has been experiencing a megadrought since 2000, with lower precipitation and higher temperatures. This drought, which spans from 2000 to 2021, is the driest 22-year period since 800 AD, with 19% of the severity in 2021 attributed to climate change. The drought severity in southwestern North America from 2000 to 2018 exceeded that of a megadrought in the late-1500s. Following the exceptional drought severity in 2021, which is 19% attributable to anthropogenic climate trends, the period from 2000 to 2021 is the driest 22-year period since at least 800 AD, and it is likely to persist through 2022, matching the duration of the late-1500s megadrought.