Climate Change and the Permafrost Carbon Feedback
High-latitude warming and the emission of permafrost carbon remains a likely global carbon cycle feedback to climate change. The sheer size of these frozen carbon pools and the rapid changes observed in the permafrost region warrant focused attention on these remote landscapes. The observations and modeling steps outlined here will help in forecasting future change. At the same time, it is imperative to continue developing effective observation networks, including remote sensing capability, to adequately quantify real-timeCO2andCH4 emissions from permafrost regions. While increased permafrost carbon emissions in a warming climate are more likely to be gradual and sustained rather than abrupt and massive, such observation networks are needed to detect the potential emissions predicted here, and also to provide early warning of phenomena and potential surprises we do not yet fully appreciate or understand. The combination of robust observations with appropriate modeling tools for forecasting change is essential to properly evaluate permafrost carbon sources. The quantification of carbon sources in addition to those that are a direct result of human activity is necessary when developing and evaluating climate change mitigation policies.