Study finds that 42% megadrought in West due to human-caused global warming: “Worst case scenario keeps getting worse.”

The American West’s Megadrought It has gotten so bad that it is now the driest since at least 1,200 years ago. Climate ChangeA new study has revealed that the scenario is being played out in real life.

A dramatic drying in 2021 — about as dry as 2002 and one of the driest years ever recorded for the region — pushed the 22-year drought past the previous record-holder for megadroughts in the late 1500s and shows no signs of easing in the near future, according to a study Monday in the journal Nature Climate Change.

This study found that 42% can be attributed human-caused climate changes.

Park Williams, a UCLA climate scientist and lead author of the study, said that climate change is changing the baseline conditions to a drier, more dry West. “This means that the worst-case scenario keeps getting worse,” Park Williams, the study’s lead author. “This is in line with what people considered the worst-case scenario in 1900s. However, I believe that we should prepare for the worst-case scenario in the future.

Williams studied soil moisture levels in the West — a box that includes California, Wyoming, Utah, Nevada, Arizona, most of Oregon and Idaho, much of New Mexico, western Colorado, northern Mexico, and the southwest corners of Montana and Texas — using modern measurements and tree rings for estimates that go back to the year 800. That’s as far back as tree rings can reliably go.

“This drought is really severe; it’s one the worst handful of years in the past 800 A.D.” Williams spoke with CBS News. “And so, humans now have to deal with a water restriction crisis in West that modern society in this area has not yet had the need to face.”

Williams studied the current drought a few years back and determined that it was a long and deep megadrought and that the worst one was in the 1500s. He thought the current drought wouldn’t be worse than that one, as megadroughts are known to fade after 20 years. He said that 2019 was a wet one, so it seemed like the western drought was coming to an end.

The region dried up in the latter half of 2020 and 2021.

According to the U.S. drought monitoring system, California was all in official drought between mid-May and the end 2021. At least three quarters of the state was at the worst two drought levels from June through December.

Williams stated, “For this drought just to have cranked back to maximum drought severity in late 2020 through 2021…is a quite emphatic declaration by this 2000s dry saying that we’re nowhere near the end.” He stated that the drought is now 5% more dry than the 1500s record.

The drought monitor reports that 55% of the U.S. West has been affected by drought, with 13% experiencing the most severe drought levels.

This megadrought really kicked off in 2002 — one of the driest years ever, based on humidity and tree rings, Williams said.

Williams said, “I was wondering whether we’d ever again see a year like 2002 in my lifetime and in fact we saw it twenty years later, in the same drought.” Although the drought levels in 2021 and 2002 were statistically equal, they still lag behind 1580 for the worst year.

Scientists say climate change is causing higher temperatures and more evaporation in our atmosphere.

Williams used 29 models to create a hypothetical world with no human-caused warming then compared it to what happened in real life — the scientifically accepted way to check if an extreme weather event is due to climate change. 42% of drought conditions can be directly attributed to human-caused warming, according to Williams. He stated that without climate change, the megadrought could have ended earlier because 2005 and 2006. would have been wet enough for it to end.

Jonathan Overpeck from the University of Michigan’s dean of environment said that the study “is a significant wake-up call.” “Climate Change is literally baking the water supply, forests, and ecosystems of the Southwest. It could get worse if we don’t stop it soon.”

Williams claimed that drought and heat are directly linked to the increase in wildfires, which have decimated the West for many years. Dry fuel is essential for fires, which is what drought and high heat promote.

Williams stated that the megadrought will eventually end due to the luck of a few good years of rainy year. Then, another one will begin.

Daniel Swain, a UCLA climate scientist, said that megadrought is likely to become a permanent feature in the climate of Colorado River watersheds during the 21st Century.

Snow is the most important thing for the West. The snowpack in the mountains melts during the summer and flows into the reservoirs.

“In the West snow is like our battery; It’s where we store energy,” J.T Reager, a NASA water scientist, told CBS News. “Now, we get less snow. The snow season has been markedly reduced.”

Climate change is making West more hot and drier. This means that more rain is falling than snow, and much of this is evaporating.

Reager stated that “over the long-term, we’re seeing with satellite data a picture of continuous drying.”

A NASA satellite is monitoring the loss of water stored underground, in reservoirs and in mountains.

 “These are some images that we’ve taken from the satellite mission from April 2010, 2015 and 2021, showing this steady drying progression of water in the West,” Reager said.