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Mapping methane reduction potential of tidal wetland restoration in the United States

October 6, 2023

Coastal wetlands can emit excess methane in cases where they are impounded and artificially freshened by structures that impede tidal exchange. We provide a new assessment of coastal methane reduction opportunities for the contiguous United States by combining multiple publicly available map layers, reassessing greenhouse gas emissions datasets, and applying scenarios informed by geospatial information system and by surveys of coastal managers. Independent accuracy assessment indicates that coastal impoundments are under-mapped at the national level by a factor of one-half. Restorations of freshwater-impounded wetlands to brackish or saline conditions have the greatest potential climate benefit of all mapped conversion opportunities, but were rarer than other potential conversion events. At the national scale we estimate potential emissions reduction for coastal wetlands to be 0.91 Teragrams of carbon dioxide equivalents year−1, a more conservative assessment compared to previous estimates. We provide a map of 1,796 parcels with the potential for tidal re-connection.

Publication Year 2023
Title Mapping methane reduction potential of tidal wetland restoration in the United States
DOI 10.1038/s43247-023-00988-y
Authors James Holmquist, Meagan J. Eagle, Rebecca Molinari, Sydney K. Nick, Liana Stachowicz, Kevin D. Kroeger
Publication Type Article
Publication Subtype Journal Article
Series Title Communications Earth & Environment
Index ID 70249465
Record Source USGS Publications Warehouse
USGS Organization Woods Hole Coastal and Marine Science Center