“Ecosystems, living things, don’t have time to adjust when you change CO 2 as fast as we’re changing it, and the geological record tells us that humans are changing CO 2 faster than anything that we know about in the last 66 million years,” she said, adding that “our entire society was built under CO 2 of just a little bit under 300 parts per million.”Ĭarbon dioxide levels in the atmosphere last year surpassed 419 parts per million and are continuing to climb. “And because they are being driven by human-caused increases in greenhouse gases in the atmosphere, we expect this drying out to just get worse and worse until we stop.”Īccording to Tierney, part of the challenge is that while there have been megadroughts and periods of high atmospheric carbon dioxide in the past, the pace of the current warming and drying is unlike anything ever experienced. “All the factors in the Southwest are leading to a drier and drier climate,” said Jonathan Overpeck, co-author of a 2020 paper on aridification. It’s a process known as aridification, and many say it’s here to stay. Some say what’s in store for the state could be akin to the conditions that drove people thousands of years ago to abandon thriving cities in the Southwest and other arid parts of the world as severe drought contributed to crop failures and the crumbling of social norms.īut unlike in those ancient civilizations, California’s current transformation is being accelerated by carbon emissions and human-caused climate change, which is creating not only longer and more severe droughts, but also hotter ones. The Golden State’s great drying has already begun to reduce snowpack, worsen wildfires and dry out soils, and researchers say that trend will likely continue, along with the widespread loss of trees and other significant shifts. Unprecedented dryness across the western United States is meeting with increasingly warm temperatures to create climate conditions so extreme that the landscape of California could permanently and profoundly change, a growing number of scientists say.

Multicam arid