Emerging role of wetland methane emissions in driving 21st century climate change

Significance Conventional greenhouse gas mitigation policies ignore the role of global wetlands in emitting methane (CH 4 ) from feedbacks associated with changing climate. Here we investigate wetland feedbacks and whether, and to what degree, wetlands will exceed anthropogenic 21st century CH 4 emissions using an ensemble of climate projections and a biogeochemical methane model with dynamic wetland area and permafrost. Our results reveal an emerging contribution of global wetland CH 4 emissions due to processes mainly related to the sensitivity of methane emissions to temperature and changing global wetland area. We highlight that climate-change and wetland CH 4 feedbacks to radiative forcing are an important component of climate change and should be represented in policies aiming to mitigate global warming below 2°C.