Southwestern North American megadrought
Megadroughts, a term used to describe periods of multidecadal drought, are a recurring feature of the North American Southwest over the past millennium.
[4] Researchers used tree ring chronologies to reconstruct summer soil moisture and snow water equivalents back to 800 CE.
Precipitation in California is limited to a single, fairly short wet season, with the vast majority of rain and snowfall occurring in the winter months across the state.
The historical and ongoing droughts in California are caused by lack of rainfall (or snowfall), higher average temperatures, and drier air masses in the atmosphere.
The 2017 Fourth National Climate Assessment (NCA4) noted that, under the worst-case scenario of RCP8.5, the annual average temperature of the Southwestern United States was projected to increase 8.6 °F (4.8 °C) by 2100.
[14] In 2013 a group of scientists from the Princeton University published a study suggesting that total deforestation of the Amazon rainforest can strongly exacerbate drought conditions in the western states of the USA.
[15][16] Later studies found that "destruction of tropical forests is disrupting the movement of water in the atmosphere, causing major shifts in precipitation that could lead to drought in key agricultural areas in China, India, and the U.S. Midwest.
Recovery to pre-2012 soil moisture levels in the most affected areas was predicted to require several decades of average rainfall.
Greg Abbott asked the Federal government to intervene to force the release of Mexican waters from the Rio Conchos that would be used by farmers in South Texas.
Lake Mead is one of the main reservoirs of the Colorado River and the declaration triggers cuts to the water supply for farmers in Arizona, Nevada, and New Mexico.
Without an alleviation of the drought conditions, The New York Times stated that further cuts affecting the 40 million people who rely upon the Colorado River for water were likely.
[25] In February 2022, the Bureau of Reclamation released projections for Lake Powell, the second largest artificial reservoir in the United States; the lower range of forecasts would result in a water level by the end of 2022 that would prohibit hydroelectric generation at the Glen Canyon Dam, which provides enough power for 400,000 homes.
[27] A 2021 study noted that increased drought conditions were now inevitable for the region, but that the most extreme modeled effects can still be avoided by climate change mitigation.
[30] The Santa Fe New Mexican called for New Mexico to learn from the driest counties how to conserve water and start preparing for a drier and hotter future.
