Permafrost thaw drives surface water decline across lake-rich regions of the Arctic

Lakes constitute 20–40% of Arctic lowlands, the largest surface water fraction of any terrestrial biome. These lakes provide crucial habitat for wildlife, supply water for remote Arctic communities and play an important role in carbon cycling and the regional energy balance. Recent evidence suggests that climate change is shifting these systems towards long-term wetting (lake formation or expansion) or drying. The net direction and cause of these shifts, however, are not well understood. Here, we present evidence for large-scale drying across lake-rich regions of the Arctic over the past two decades (2000–2021), a trend that is correlated with increases in annual air temperature and autumn rain. Given that increasing air temperatures and autumn rain promote permafrost thaw, our results indicate that permafrost thaw is leading to widespread surface water decline, challenging models that do not predict a net decrease in lake area until the mid-twenty-first or twenty-second centuries.