Whats at stake as permafrost thaws?
There are two principal impacts of thawing permafrost. Locally, when ice in the ground melts, the soil loses its strength, and infrastructure built on the surface may settle into the ground, creating, for example, the undulating road surfaces so common in the north. Globally, a catastrophic consequence of permafrost thawing may be the decomposition and release to the atmosphere of the vast quantities of carbon now stored as frozen peat. Considerations such as this are part of the reason some scientists have warned that we may be close to a climatic “tipping point.” You’ve been keeping tabs on the ground temperatures in northwest Canada and maintaining a long record of active-layer development in the tundra. What have you found? The Mackenzie delta area is the most rapidly warming part of northwest North America, or has been over the last 35 years. Air temperatures have risen by over 2.5°C since 1970. In the outer Mackenzie delta it appears that ground temperatures have risen by 1.5 to
