Image Description – Permafrost Thaw, Northern British Columbia

Permafrost Thaw, Northern British Columbia. Along the Alaska Highway and throughout most of Alaska, northern British Columbia and Yukon Territory, one can now find permafrost thaw. Typically, permafrost thaw creates lakes where the loss of ice partially or completely submerges vegetation. Often the water drains away leaving a bomb crater landscape littered with fallen trees. Not only are CO2 and methane released from the permafrost as it thaws, but the terrestrial ecology emits its stored greenhouse gases and loses its sequestration capacity. Various studies have shown permafrost is now a net emitter of greenhouse gases and is on average, no longer sequestering carbon. The thaw has just begun and it will increase nonlinearly because of simple physics of warming called the “heat of fusion,” which can be directly interpreted as the heat of freezing or thawing. It takes 289 times more heat energy to thaw ice from 32 degrees to 33 degrees (F), than it does to change the temperature of ice or water one degree when the heat of ice formation is not involved. We have already invested an enormous amount of heat into permafrost to start its thaw, so additional warming substantially goes into thawing and not the heat of fusion.