A hidden climate system component: observations and modelling of subsea permafrost

Our warming global climate has a number of built-in amplifying effects for components that have a positive feedback to forcing. Permafrost has been identified as such a positive feedback. Permafrost contains organic carbon and greenhouse gases. When it thaws, these are mobilized and contribute to further warming. Permafrost  also exists beneath the marginal seas of the Arctic Ocean, a relict of past glacial periods. In this talk, I describe what we know about subsea permafrost in terms of its composition and distribution and consider its potential importance as a component of the global climate system.

---