Climate change reduces wetland size and shifts its seasonal regime in North America

Abstract

Inland wetlands are important ecosystems sustained by excessive water. Climate change can alter wetland extent and functions, but such impacts are unclear because hydroclimatic changes influence wetland processes in different ways. Here we project future changes in wetland characteristics over North America under low and high emission scenarios, using a state-of-the-science Earth system model that represents both fluvial and pluvial inundation processes. We project a reduction in wetland areas in all seasons except winter. At the continental scale, annual wetland area decreases by ~10% under the high emission scenario by the end of the century, with much larger and divergent regional changes of up to ±50%. However, the evolution of functional wetland habitats can be different from that of wetland area dynamics. The wetland reduction increases with global warming level as temperature is projected to play a more dominant role in wetland dynamics than precipitation under the high emission scenario.