@Article{Kooperman_GRL_20181128, author = {Gabriel J. Kooperman and Megan D. Fowler and Forrest M. Hoffman and Charles D. Koven and Keith Lindsay and Michael S. Pritchard and Abigail L. S. Swann and James T. Randerson}, title = {Plant Physiological Responses to Rising CO$_2$ Modify Simulated Daily Runoff Intensity With Implications for Global-Scale Flood Risk Assessment}, journal = GRL, volume = 45, number = 22, pages = {12,457--12,466}, doi = {10.1029/2018GL079901}, day = 28, month = nov, year = 2018, abstract = {Climate change is expected to increase the frequency of flooding events and, thus, the risks of flood-related mortality and infrastructure damage. Global-scale assessments of future flooding from Earth system models based only on precipitation changes neglect important processes that occur within the land surface, particularly plant physiological responses to rising CO$_2$. Higher CO$_2$ can reduce stomatal conductance and transpiration, which may lead to increased soil moisture and runoff in some regions, promoting flooding even without changes in precipitation. Here we assess the relative impacts of plant physiological and radiative greenhouse effects on changes in daily runoff intensity over tropical continents using the Community Earth System Model. We find that extreme percentile rates increase significantly more than mean runoff in response to higher CO$_2$. Plant physiological effects have a small impact on precipitation intensity but are a dominant driver of runoff intensification, contributing to one half of the 99th and one third of the 99.9th percentile runoff intensity changes.} }