Sea-ice loss threatens permafrost
The rapid disappearance of Arctic sea ice could warm temperatures inland and hasten permafrost's thaw
Environmental Science and Technology,
As Arctic sea ice vanishes, permafrost could warm much more quickly than previously thought, according to new research. Melting permafrost could then release its vast stores of carbon into the atmosphere, accelerating global warming. The study is the first to link the loss of sea ice to warmer temperatures hundreds of miles inland.
The extent of Arctic sea ice has declined precipitously in recent years; last year, it reached a modern-day record low that was 39% below the long-term average from 1979 to 2000. Air temperatures over Arctic land were also warmer than usual late last summer and fall, prompting researchers from the
To find connections between land and sea temperatures, David Lawrence of NCAR and colleagues analyzed global climate simulations with NCAR's Community Climate System Model. The simulations revealed that during periods of sustained rapid ice loss, the rate of climate warming over northern
Although the mechanisms that link sea ice to inland warming are not fully understood,
This year's sea-ice extent is currently on track to break last summer's record low. However, scientists are not yet sure whether the trend will continue. If sea ice continues to disappear, "we may see a period of accelerated change,"
(c) 2008 American Chemical Society