Scientists from Columbia University have recorded the worst and longest drought in the Western United States in the past 1200 years. It is caused by climate change caused by human activity. This is reported in a press release on Phys.org.
Researchers analyzed annual tree rings that grow in nine States, including Oregon, Wyoming, New Mexico, as well as in southwestern Montana and Northern Mexico. Experts compared the drought, which began in 2000 and continues to this day, with four other megadroughts for 1200 years. The key parameter was soil moisture, which demonstrated that the current drought is the worst in the history of modern society.
A moderate long-term drought, which is not unusual in itself, is compounded by an increase in average temperatures, which are currently 2.9 degrees Celsius higher than in previous years. This significantly reduces the moisture content of the soil.
To assess the contribution of global warming, scientists used 31 computer models to compare the current situation with a hypothetical world that does not burn fossil fuels. It turned out that the contribution of anthropogenic climate change to drought reaches 47 percent.
The current drought has lasted only two decades, although, in the past, mega-droughts have lasted at least 28 years. Researchers believe that at the moment it makes sense to talk about an incipient mega-drought, although it is already considered a record strong and the first such phenomenon in the entire history of observations.