The U.S. and Mexico are now at risk of “megadrought” due to rising temperatures. Researchers warned that some areas may have already been feeling the drastic changes and heading to more extreme conditions.
The new study, published in the journal Science, analyzed data on precipitation levels in the past century and soil moisture levels in tree rings in the last 1,200 years. It shows that the southwestern North American (SWNA) region is now on the path to a drought worse than any in recorded history.
There were also indications that a megadrought has already started in some parts of the region. The study does not provide projections as it shows “where we are now,” according to Park Williams, bioclimatologist at Columbia University.
“We now have enough observations of current drought and tree-ring records of past drought to say that we’re on the same trajectory as the worst prehistoric droughts,” he said.
Researchers said the increasing temperatures caused by human activities significantly contributed to worsening droughts. With the hotter weather, the world may no longer experience the levels of precipitation seen in past centuries and experience longer, drier and more widespread droughts, ScienceAlert reported Monday.
Looking at megadroughts in the past centuries, researchers found that the U.S. had worse droughts in the past 19 years because of very low levels of moisture. In addition, wider areas have been feeling the effects of hotter weather.
The study suggests global warming caused half of the current drought’s pace and half of its severity. In some areas in the southwestern North American region, hotter air has been taking more moisture out of the ground.
“It doesn’t matter if this is exactly the worst drought ever,” Benjamin Cook, environmental scientist at Columbia University, said. “What matters is that it has been made much worse than it would have been because of climate change.”
While parts of the Americas are facing more challenges because of hotter days, scientists fear that the Arctic has been losing ice faster than previously thought. One research predicts that the North Pole will become ice-free in the next three decades because of global warming.