What Climate Models Get Wrong About Future Water Availability

One of the most challenging questions about climate change is how Earth’s warming atmosphere will affect water availability across the globe. Climate models present a range of possible scenarios—some more extreme than others—which can make it difficult for cities, states, and countries to plan ahead. Now, however, in a new study, Padrón et al. suggest a way to reduce uncertainty using precipitation patterns from the past. A rule of thumb for global warming’s impact on Earth’s water availability that was sometimes proposed in the past was that dry regions will get drier and wet regions will get wetter, also known as the DDWW hypothesis. But mounting evidence suggests the reality is more complicated.