Lake Mead

Arizona, California and Nevada have narrowly averted a regional water crisis by agreeing to reduce their use of Colorado River water over the next three years. This deal represents a temporary solution to a long-term crisis. Nonetheless, as a close observer of western water policy, I see it as an important win for the region. Seven western states – Colorado, Wyoming, Utah, New Mexico, Arizona, Nevada and California – and Mexico rely on water from the Colorado River for irrigation for 5.5 million acres and drinking water for 40 million people. Their shares are apportioned under a compact negotiated in 1922. We now know, thanks to tree-ring science, that its framers wildly overestimated how much water the river contained on a reliable basis. And climate change is making things worse. Some recent commentators have argued for revamping the compact. The lawyer in me shudders to think of the utter chaos that would ensue as states, tribes that were left out of the original...

After three years of extreme drought, the Western U.S. is finally getting a break. Mountain ranges are covered in deep snow, and water reservoirs in many areas are filling up following a series of atmospheric rivers that brought record rain and snowfall to large parts of the region. Many people are looking at the snow and water levels and asking: Is the drought finally over? There is a lot of nuance to the answer. Where you are in the West and how you define “drought” make a difference. As a drought and water researcher at the Desert Research Institute’s Western Regional Climate Center, here’s what I’m seeing. How fast each region recovers will vary The winter of 2023 has made a big dent in improving the drought and potentially eliminating the water shortage problems of the last few summers. I say “potentially” because in many areas, a lot of the impacts of drought tend to show up in summer, once the winter rain and snow stop and the...

There’s an old joke about the fellow who has his left foot in a bucket of ice water and the right in a bucket of hot water, so that his overall temperature is average. That seemed to apply to the climate during 2022’s northern summer of extremes. Global warming is undoubtedly a factor, but just how the increasing extremes – heat waves, droughts and floods, sometimes one on top of the other – are related can be bewildering to the public and policymakers. As a climate scientist, I’ve been working on these issues for more than four decades, and my new book, “The changing flow of energy through the climate system,” details the causes, feedbacks and impacts. Let’s take a closer look at how climate change and natural weather patterns like La Niña influence what we’re seeing around the world today. The June-August 2022 global land and ocean surface temperature was 1.6 degrees Fahrenheit...