Editor’s note: This week, Celsias’ editor Craig Mackintosh takes a look at one of the biggest threats posed by global climate change: melting permafrost. This post was originally published on September 18, 2007.

As fascinating as it may seem to see a scientist potentially holding a pile of mammoth-poo in his hands, this is not a good sign.

Over 10% of the earth’s surface is covered in tundra, a thin layer of slow-growing plant matter (dwarf shrubs, grasses, mosses, lichens, etc.), which covers a frozen bog of organic matter called permafrost.

Due to very short growing seasons and very low temperatures, the expansive areas of tundra in the frigid north of Russia, Alaska, Canada, etc., can only support an incredibly slow breakdown of organic material. Essentially, permafrost stores thousands of years of plant and animal organic matter. It is a vast carbon sink. Or, at least, it was….

If you’ve ever heard the terms ‘runaway effects’ or ‘feedback loops’ in connection with climate change - this is one of the most significant.

As the world warms, the permafrost melts - speeding up the ‘metabolism’ of these regions. This allows micro-organisms that normally struggle to function at lower temperatures to suddenly begin working at an accelerated rate - subsequently releasing incomprehensible amounts of CO2, and, even worse, methane, into the atmosphere. Methane is "over 20 times more effective in trapping heat in the atmosphere than carbon dioxide (CO2) over a 100-year period" (USEPA). Currently, scientists state our atmosphere contains two and a half times as much methane as it did in pre-industrial times, and with millions of square miles of permafrost beginning to melt, this looks set to increase dramatically.

Global warming melts permafrost. Permafrost releases billions of tonnes of greenhouse gases. Global warming gets a shot in the arm. This is one of many feedback loops we’ll look at over the next weeks.

Although on the decline, there are still an inordinate amount of climate skeptics out there who fail to grasp the implications of rising global temperatures - some even naively look forward to warmer winters and hotter summers, believing the most important impacts for them will be the kind of shirt they can wear. Naivety, with some subjects, can be cute and becoming - but with climate science it’s just plain dangerous.

If you have ideas on feedback loops you’d like to see on Celsias, or even entire posts you’d like to submit, feel free to get in touch.

Further Reading:

• Alaskan Villages Under Siege
• Methane bubbles climate trouble