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

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.