Methane Released from Sub-Arctic North American Wetlands Could Triple by 2100 Without 1.5°C Mitigation Pathways

Science Advances, 1 March 2023

Freshwater wetlands across the northern US and Canada will likely release three times more methane than today by the end of the century if temperatures exceed 3-4°C, but these emissions could be nearly halved by following a low emissions pathway. Tiny microbes in wetlands release large amounts of methane into the atmosphere during the spring and summer before winter frost. As temperatures increase across the sub-Arctic, frozen soils thaw earlier and growing season lengthens, allowing microbes to release more methane gas for longer periods. This positive feedback loop between global temperature rise and carbon emissions from wetlands, along with those from permafrost and peatlands, emphasizes the need to include such emissions when developing national and global mitigation targets aimed at holding temperatures within the 1.5°C limit.

https://www.science.org/doi/10.1126/sciadv.ade1112