This is a scenario of climate change that is currently playing out live, according to a new study.
According to Monday’s study in the journal Nature Climate Change, a dramatic drying in 2021 — almost as dry as 2002 and one the driest years for the region — has pushed the 22-year-old drought past the record-holder for megadroughts of the late 1500s. It shows no signs of abating in the near future.
This study found that 42% can be attributed human-caused climate change.
Park Williams, a UCLA climate hydrologist and study lead author, stated that “Climate Change is shifting the baseline conditions towards a drier. This is in line with the worst-case scenario that people considered in the 1900s. However, I believe we should be preparing for worse future conditions.
Williams examined soil moisture levels in West, which includes California, Wyoming and Utah, Nevada and Arizona. He used modern measurements and tree rings to estimate the back year 800. This is about the most reliable tree-ring-based estimate you can make.
Williams, a researcher, studied the current drought a few years back and determined that it was a long and deep “megadrought” with the worst being in the 1500s. Because megadroughts tend to end after 20 years, he thought the current drought would not surpass it. He said that 2019 was a dry year, so the western drought could be ending.
However, the region was dry in 2021 and 2020.
According to the U.S. drought monitor, California was in an official drought state from mid-May through the end of 2021. At least three quarters of California was at the worst two drought levels between June and Christmas.
Williams stated that the drought has “just cranked back to maximum drought severity in late 2020-2021 is an emphatic statement made by this 2000s drought, saying that we are nowhere near the end.” He stated that the drought is now 5% more dry than the 1500s record.
According to the drought monitor, 55% of the U.S. West are in drought. 13% of them are experiencing the worst drought conditions.
Williams stated that the megadrought began in 2002, which was based on tree rings and humidity.
Williams stated that Williams was asking if they would ever see another year like 2002 in their lives. In fact, Williams saw it in the same drought 20 years later. Although the drought levels of 2002 and 2021 were statistically equal, they still lag behind 1580 for the worst year.
Scientists say climate change is increasing heat and evaporation due to the burning fossil fuels.
Williams created a hypothetical world using 29 models. He then compared it with what actually happened in real life. This is the scientifically accepted method to determine if extreme weather events are due to climate change. His research showed that 42% are directly due to human-caused global warming. He said that the megadrought wouldn’t have occurred without climate change because 2005 and 2006 would not have been sufficiently wet to end it.
Jonathan Overpeck, University of Michigan dean of environment, said that the study was “an important wake-up call.” He wasn’t involved in the study. Climate change is literally baking water supplies and forests in the Southwest. It could get worse if we don’t stop it soon.
Williams stated that there is a direct correlation between drought and heat, and the increase in wildfires which have decimated the West over the years. Dry fuel is what drought and heat provide for fires.
Williams stated that this megadrought would end eventually due to the good fortune of a few rainy years. Then, another one will begin.
Daniel Swain, a UCLA climate scientist, stated that megadrought is likely to become a permanent feature in the climate of Colorado River watersheds during the 21st Century.
