November 29, 2023

Advancing wetland restoration as a climate change mitigation strategy

Posted by Caitlin Bergstrom

By Robert Feder, AGU Fall 2023 intern.

Wetland ecosystems have a tremendous capacity to sequester carbon owing to inefficient organic matter decomposition in waterlogged soils. Modern wetlands like peatlands have been accumulating carbon for millennia, thereby making wetland soils a major reservoir of stable carbon on Earth. Then, in three centuries, an estimated twenty-one percent (21%) of Earth’s inland wetlands were lost to drainage or conversion, with much of the loss concentrated in the United States, Europe, and China. The wetlands that remain are under threat due to climate change, saltwater intrusion, and pollution. 

Wetland drainage and anthropogenic threats have enabled the release of stable carbon from wetland soils to the atmosphere as planet-warming greenhouse gases. Society’s ability to limit global warming to 1.5 °C above pre-industrial levels depends, in part, on nations considerably increasing the amount of carbon stored in wetland soils.  

Ecosystem restoration is defined as the process of halting and reversing degradation, resulting in improved ecosystem services — like carbon sequestration — and recovered biodiversity. Policy solutions that support the protection and restoration of the world’s remaining wetlands are urgently needed to mitigate climate change and its disastrous long-term effects. Examples of such solutions include: 

  • Federal investments in wetland restoration research and development. Robust federal investments are needed to address unresolved questions to restoring wetlands to improve carbon sequestration. The Carbon Dioxide Removal Research and Development (CDR R&D) Act of 2023 would authorize $1.08 billion to the National Oceanic and Atmospheric Administration (NOAA) and $393 million to the U.S. Army Corp of Engineers to conduct field trials of coastal wetland restoration optimized for carbon sequestration, among other purposes. The CDR R&D Act would further authorize $170 million to the National Aeronautics and Space Administration to map and evaluate the carbon sequestration potential of coastal wetlands. Congress should make sustained federal investments in wetland restoration research to develop innovative techniques for restoring the full carbon sequestration potential of coastal wetlands. 
  • Accelerated deployment of wetland restoration projects. The Bipartisan Infrastructure Law (BIL) of 2021 and Inflation Reduction Act (IRA) of 2022 appropriated $491 million and $2.6 billion, respectively, to NOAA to restore coastal ecosystems and boost coastal community resilience. To date, NOAA’s Office of Habitat Conservation has awarded more than $480 million in competitive grants to support 109 coastal habitat restoration projects across the United States and U.S. territories. The Office of Habitat Conservation should prioritize large-scale restoration of (1) carbon-rich coastal wetlands and (2) coastal wetlands with high carbon sequestration potential when awarding the remaining BIL and IRA funds to communities. The Federal Emergency Management Authority (FEMA) also supports wetland restoration through the Building Resilient Infrastructure and Communities (BRIC) grant program. Congress should require that twenty percent of BRIC funding for competitive national grants be set aside for nature-based hazard mitigation projects, as advocated for by the Natural Resources Defense Council. Federal agencies must accelerate deployment of wetland restoration projects — in parallel with decarbonization of the economy — in order to suppress global peak temperature and cool the planet within the century. 
  • Open access to wetland restoration research data. Open access to wetland restoration research data would facilitate knowledge sharing and international collaboration among scientists, land managers, and policymakers. Congress should ensure that research data collected by the federal government or generated using federal funds be in compliance with FAIR principles, i.e., data are Findable, Accessible, Interoperable, and Reusable, as appropriate. Improving data accessibility will, in turn, facilitate the development of innovative evidence-based strategies and policies to restore the carbon sequestration function of wetland ecosystems. 

Protecting and restoring the world’s remaining wetlands is vital to maintaining some semblance of a habitable planet Earth. Governments must ambitiously increase the amount of carbon stored in wetland soils by investing in wetland restoration research, accelerating the deployment of wetland restoration projects, and sharing their knowledge with the world. It is time to unlock the full carbon sequestration potential of wetland soils.