Alarm bells are beginning to sound on drought risk in western North America and around the world, including some important and populous food growing regions.
Here’s an article in Science talking about “an emerging North American megadrought”:
Severe and persistent 21st-century drought in southwestern North America (SWNA) motivates comparisons to medieval megadroughts and questions about the role of anthropogenic climate change. We use hydrological modeling and new 1200-year tree-ring reconstructions of summer soil moisture to demonstrate that the 2000–2018 SWNA drought was the second driest 19-year period since 800 CE, exceeded only by a late-1500s megadrought. The megadrought-like trajectory of 2000–2018 soil moisture was driven by natural variability superimposed on drying due to anthropogenic warming. Anthropogenic trends in temperature, relative humidity, and precipitation estimated from 31 climate models account for 47% (model interquartiles of 35 to 105%) of the 2000–2018 drought severity, pushing an otherwise moderate drought onto a trajectory comparable to the worst SWNA megadroughts since 800 CE.
Science
Here’s an article in Earth’s Future (from the American Geophysical Union, which I consider prestigious) talking about some other regions with high drought risk.
The multi‐model ensemble shows robust drying in the mean state across many regions and metrics by the end of the 21st century, even following the more aggressive mitigation pathways (SSP1‐2.6 and SSP2‐4.5). Regional hotspots with strong drying include western North America, Central America, Europe and the Mediterranean, the Amazon, southern Africa, China, Southeast Asia, and Australia. Compared to SSP3‐7.0 and SSP5‐8.5, however, the severity of drying in the lower warming scenarios is substantially reduced and further precipitation declines in many regions are avoided. Along with drying in the mean state, the risk of the historically most extreme drought events also increases with warming, by 200–300% in some regions.
AGU
So, our species has identified the problem and identified solutions, but is continuing to fail to actually do anything. This is a little like the coronavirus, where early action could have been cheap and effective compared to the drastic action required when the problem became really obvious to even the densest politicians. It’s unlike the coronavirus in that once the problem becomes obvious to even the densest politicians, there may be no effective measures that can be taken, even maximally disruptive ones.
The mention of the Amazon and Southeast Asia are particularly concerning to me. These are both important food growing regions and biodiversity hot spots.