Melting of permafrost

Dr Robert Holmes, a researcher at the Woods Hole Research Centre in Massachusetts has in a new report outlined the negative feedback mechanism relating to the thawing of permafrost in Siberia, Alaska and other parts of the Arctic.

Dr. Holmes explains how large amounts of organic matter (dead plants and animals) locked up in permafrost, frozen and preserved many hundreds of years could accelerate global warming . As the permafrost thaws, the organic matter starts to decompose and convert to carbon dioxide (CO2). More CO2 leads to higher temperatures, causing more permafrost to thaw, which in return leads to further release of ancient organic matter.

The consequences is that the amount of water flowing to the Arctic from the Lena River (the ninth-longest river in the world ) has increased 7 per cent in the last seven decades. With a river as large as the Lena, that is a significant amount.

Increased freshwater output by the Lena and other Arctic rivers are expected to decrease the salinity in the Greenland-Iceland-Norwegian seas. The ocean salinity level is closely linked to the Gulf stream, which scientists fear could slow or completely stop by declining salinity levels.

In the event that the Gulf stream is slowed or stopped, it is expected to trigger a new ice age in Northern Europe.