The 20-year mega-drought in southwestern North America is at a record high of 1,200 years, according to a study released Monday, which predicts that this episode, intensified by climate change, will probably continue into 2022.
The western United States and northern Mexico have suffered from exceptional droughts since 2000, two decades after it became possible to qualify as a “mega-drought”.
“After an exceptionally severe drought in 2021, 19% of which is attributed to human-induced climate change, the period 2000-2021 was at least 800 years to 22 years dry,” the researchers wrote in the scientific journal. Natural climate change.
Due to the very high temperatures and low rainfall between the summer of 2020 and the summer of 2021, this mega-drought “exceeded its intensity” in the late 1500s, the worst in a record of 1,200 years previously reviewed by scientists. UCLA University in Los Angeles.
And since 2000, the soil moisture deficit has more than doubled during any drought in the 20th century.
In addition, the study predicts that this episode will “probably last until the year 2022, reaching the mega-drought period of the late 1500s”.
Despite the return of rain, the impact will extend from southern Montana to northern Mexico, from the Pacific Ocean to the Rocky Mountains.
“It’s very unlikely that this drought will end in just one rainy year,” commented Park Williams, lead author and geographer at UCLA.
“Without climate change, the last 22 years would probably be the driest in 300 years,” but “not close to the mega-famines of the 1500s, 1200s and 1100s,” he said in a press release.
According to the study, climate change is linked to human activity, which multiplies episodes of heat waves and disrupts precipitation, causing 42% of the soil moisture deficit in the region between 2000-2021 and 19% in 2021. .
This chronic drought in the western United States prompted the federal government last August to decree for the first time in history the water limits affecting Lake Mead, the nation’s largest artificial reservoir served by the Colorado River.