Normally droughts would occur only once in a decade but now due to climate change they would be 70% more frequent, global scientists said. This would mainly occur in western US and bring more wildfires, drain reservoirs and trigger water shortage.
This week 94% of the West is in drought, with six states entirely in drought conditions, according to the US Drought Monitor. On the Colorado River, Lake Mead and Lake Powell have been draining alarming, threatening the West’s water supply and hydropower generation in coming years.
Though summer rainfall brought some relief to the Southwest, the unrelenting drought there is about to get worse with La Niña, David DeWitt, director at the National Oceanic and Atmospheric Administration’s Climate Prediction Center said.
La Niña is a natural phenomenon marked by cooler-than-average sea surface temperatures across the central and eastern Pacific Ocean near the equator, which causes shifts in weather across the globe.
In the Southwest, La Niña typically causes the jet stream, upper-level winds that carry storms around the globe to shift northwards.
NOAA’s latest projections show a 70% to 80% chance of La Niña emerging during the Northern Hemisphere during the winter season. With La Niña conditions coupled with warming temperatures, DeWitt said the Southwest will see enhanced evaporation that will intensify drought in certain places.
“The net water balance going forward, from this point as the summer monsoon ends, is that we’re going to see conditions continue to dry out,” DeWitt said.
“Places that have droughts will kind of persist or intensify, and places that don’t have drought right now because it was recently ameliorated, we expect drought is going to redevelop.”
The NOAA report concluded that climate change-fueled drought will continue to worsen and impose greater risks on the livelihoods and well-being of over 60 million people living in the Southwest, as well as the larger communities that rely on their goods and services.