Permafrost carbon feedback

Permafrost carbon feedback is the warming loop in which rising temperatures thaw frozen ground, allowing stored organic carbon to decompose and release greenhouse gases that cause further warming.

Permafrost: Ground that remains at or below 0°C for at least two consecutive years. Its thaw is the physical trigger that exposes frozen organic matter to decomposition.
Radiative forcing: A change in Earth’s energy balance caused by altered atmospheric composition or other influences. Additional carbon dioxide and methane increase the energy retained in the climate system.
Permafrost monitoring: The measurement of ground temperature, frozen-ground extent, and related changes over time. Long-term observations reveal where warming is thawing permafrost.
Permafrost carbon pool: The organic carbon stored in permafrost and associated frozen soils. Estimates of its size and accessibility constrain the potential scale of the feedback.
Yedoma: Ice-rich, carbon-rich permafrost deposits formed during the Pleistocene in parts of Siberia and Alaska. Its thaw can expose large stores of ancient organic carbon.
Soil organic carbon: Carbon contained in dead plant, animal, and microbial material within soil. Permafrost stores large quantities of this material, accumulated over millennia.
Global carbon budget: An accounting of carbon sources and sinks that constrains allowable emissions for a temperature target. Permafrost emissions reduce the carbon that can be emitted while meeting climate targets.
Eddy covariance: A method that estimates exchanges of gases and energy between ecosystems and the atmosphere from turbulent wind measurements. It measures carbon dioxide and methane fluxes from thawing landscapes.
Abrupt permafrost thaw: Rapid, localized thaw of ice-rich permafrost that causes sudden ground collapse or drainage changes. Abrupt thaw can mobilize carbon faster than gradual-thaw assumptions imply.
Thermokarst lakes: Lakes formed when thawing, ice-rich permafrost ground subsides and fills with water. Their oxygen-poor sediments can produce substantial methane.

Linked from 9 pages