Bridging the Gap Between Simple Metrics and Model Simulations of Climate Change Impacts on Land Hydrology

For many years now, studies on climate change impacts on continental hydrology have suffered from conflicting results between different approaches. On the one hand, studies relying on widely used, simple metrics of land water availability, such as the Aridity Index and Palmer Drought Severity Index, depict predominantly drier future land surface conditions, when driven by climate change projections from global models. On the other hand, the same climate models also generate their own land surface projections, which exhibit balanced changes in land hydrology, with spatially heterogenous changes in soil moisture or runoff. Writing in Earth's Future, Scheff et al. (2022, https://doi.org/10.1029/2022ef002814) provide a comprehensive modeling assessment of the various processes responsible for these contrasted projections, resolving this conflict and thereby improving our understanding of future land hydrology.