“A “megadrought” gripping the western United States is the worst one in 500 years, scientists say. And it’s the first to be influenced by human-caused climate change.”
Chelsea Harvey, Scientific American, April 17, 2020
This year, the megadrought in the West hit 22 years. That means over a third of my life has been spent looking for clouds and hoping for rain and snow that never comes. It’s also the worst drought since the late 800s.
In my region, the Southwest, drought is especially severe thanks to La Niña. When La Niña is dominant, cloud formation and precipitation in the Southwest decreases. But this megadrought has an additional driver: the 2 degree rise in temperature all across the West increases evaporation and aridity. A study by the Desert Research Institute calls this “atmospheric thirst” and says that, just as people and plants demand more water when it’s hotter, so does the atmosphere.
Study co-author Justin Huntington describes the impact of a thirsty atmosphere saying, “Our analysis suggests that crops now require more water than they did in the past and can be expected to require more water in the future.”
In fact, studies indicate that warming temperatures and resulting atmospheric thirst are responsible for 42% of soil moisture loss we’re currently seeing. This translates into an additional one million acre-feet of water for crops growing in California’s San Joaquin Valley. It’s an area that produces a quarter of the Nation’s food, including 40 percent of the fruits, nuts, and other table foods we eat in the U.S.
You can see the impacts of atmospheric thirst all across the country:
Dr. Peter Sousonis explains what’s happening in the West this way: “The bad news is that drought begets drought. That is, high mean temperatures prime the climate system to reach extreme temperatures more easily. Very warm air over a region distorts the flow pattern at upper levels, so rain-laden weather systems are diverted. As the land surface dries out, the air warms even more because there is little evaporative cooling to counter the heating. The process spawns a positive feedback loop that exacerbates aridity and prolongs drought conditions.”
Based on his latest research, UCLA climate scientist Park Williams says, “Not only is this drought continuing to chug along, it’s proceeding at as full-steam pace as it ever has been.” His research shows Earth’s warming climate has made the western drought about 40 percent more severe, and there’s a very strong chance the drought will continue through 2030.
Today, water levels in Lake Powell have dropped to emergency levels. This reservoir, along with Lake Mead, provides 40% of the water used in Arizona. It’s possible that drinking water for 7,500 residents of Page, Arizona, and the Navajo community of LeChee will be cut off and farmers’ supplies will be further reduced. In fact, many farmers north of where I live have already sold their properties to power companies to install solar farms. That may be helpful, as there are concerns that as lake levels continue to recede, the dam at Lake Powell will no longer be able to provide hydroelectric power. Without some other option, 5 million people will lose electricity.*
The drought is also creating a new kind of climate refugee. In addition to the farmers leaving their homes and property, there are the ranchers and residents burned off their land and out of their homes by the increasing intensity of wildfires. It includes one of my best friends from High School and his wife who lost their home in the December 30, 2021 wildfire that burned more than a thousand homes in Westminster and Superior, Colorado.
All of this is so big that I have little influence. It hardly matters that I change my water and power use because I need so many more to join me. My vote barely matters either as most legislation that might help is blocked. So, instead, I do what I can. I’m writing about drought and how it affects you – from more cattle hitting the market and reducing your profits, to the price of hay increasing – and I give you tools that might help you be successful. I hope it helps.
Thanks for reading!
Kathy
* As I was writing this piece, the Bureau of Reclamation was requiring all states in the Colorado River Water compact to provide plans for preserving water levels in Lake Powell. Their responses, delivered last Friday, will protect the Lake Powell for one more year, but will further impact water levels in Lake Mead below. It’s a temporary fix that gives power companies and water users a bit of time to come up with solutions that will hopefully correspond with the new climate reality we live in.
