Large contribution from anthropogenic warming to an emerging North American megadrought Science

A trend of warming and drying Global warming has pushed what would have been a moderate drought in southwestern North America into megadrought territory. Williams et al. used a combination of hydrological modeling and tree-ring reconstructions of summer soil moisture to show that the period from 2000 to 2018 was the driest 19-year span since the late 1500s and the second driest since 800 CE (see the Perspective by Stahle). This appears to be just the beginning of a more extreme trend toward megadrought as global warming continues. Science , this issue p. <related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6488" page="314" related-article-type="in-this-issue" vol="368" xlink:href="10.1126/science.aaz9600">314</related-article> ; see also p. <related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6488" page="238" related-article-type="in-this-issue" vol="368" xlink:href="10.1126/science.abb6902">238</related-article> Grant no. NA15OAR4310144 Grant no. NA16OAR4310132