# Climate change will reduce North American inland wetland areas and disrupt their seasonal regimes

## TL;DR

Climate change is expected to shrink North American inland wetlands and disrupt their seasonal patterns, especially during summer and in cold regions.

## Contribution

The study uses Earth system modeling to project climate-driven changes in wetland extent and seasonality across North America.

## Key findings

- Annual wetland area is projected to decrease by ~10% under a high emission climate scenario.
- Wetlands in cold regions will shrink due to increased infiltration from warmer temperatures reducing soil ice.
- Summer drying in wetlands is expected to impact biodiversity in key habitats like the Everglades and upper Mississippi.

## Abstract

Climate change can alter wetland extent and function, but such impacts are perplexing. Here, changes in wetland characteristics over North America from 25° to 53° North are projected under two climate scenarios using a state-of-the-science Earth system model. At the continental scale, annual wetland area decreases by ~10% (6%-14%) under the high emission scenario, but spatiotemporal changes vary, reaching up to ±50%. As the dominant driver of these changes shifts from precipitation to temperature in the higher emission scenario, wetlands undergo substantial drying during summer season when biotic processes peak. The projected disruptions to wetland seasonality cycles imply further impacts on biodiversity in major wetland habitats of upper Mississippi, Southeast Canada, and the Everglades. Furthermore, wetlands are projected to significantly shrink in cold regions due to the increased infiltration as warmer temperature reduces soil ice. The large dependence of the projections on climate change scenarios underscores the importance of emission mitigation to sustaining wetland ecosystems in the future.

Earth system modeling is used to project future changes in North American wetlands. Climate change will reduce inland wetland areas and disrupt their seasonal regimes, with substantial summer drying and shrinkage in cold regions.