Increasing Mississippi river discharge throughout the 21st century influenced by changes in climate, land use, and atmospheric CO2

Abstract

Previous studies have demonstrated that changes in temperature and precipitation (hereafter climate change) would influence river discharge, but the relative importance of climate change, land use, and elevated atmospheric CO2 have not yet been fully investigated. A process-based projection for the Mississippi River basin suggests that river discharge would be substantially enhanced (10.7–59.8%) by the 2090s compared to the recent decade (2000s), although large discrepancies exist among different climate, atmospheric CO2, and land use change scenarios. Our factorial analyses further indicate that the combined effects of land use change and human-induced atmospheric CO2 elevation on river discharge would outweigh climate change effect under the high-emission scenario (A2) of the Intergovernmental Panel for Climate Change, while climate change would still play the dominant role under the low-emission scenario (B1). This study highlights the important role of anthropogenic factors in influencing future hydrological processes and water resources.