The researchers used models that looked at a number of very complex systems. “These models are trying to simulate all the processes that we think are relevant in the climate system,” says Cook. Precipitation is incredibly important, but so is soil moisture, and temperature. The researchers found that for most of these areas, precipitation will decline during a megadrought. Weirdly, though, a few places might see more precipitation during a megadrought. Unfortunately, rising temperatures in those spots mean that even with the rain, moisture in the soil will be evaporated faster than it is now, and the overall effect will still tend towards drought.