Methane is also beginning to escape from the permafrost.

One fifth of the earth's surface is covered by permafrost.

And what they found, by doing research into the permafrost, was this bacteria.

HEND helped lead to the discovery that 15 per cent of the surface of Mars was permafrost.

It's also probably one the most vulnerable of the oldest living things, because if the permafrost melts, it won't survive.

They've survived for millennia in desert, in the permafrost, at the tops of mountains and at the bottom of the ocean.

As Earth warms, now because of extra CO2 we put in the atmosphere, ice will melt, and CO2 and methane will be released by warming ocean and melting permafrost.

If just three percent of the carbon locked up in the arctic permafrost is released as the world warms, it would offset all the savings that we need to make, in carbon, over the next 40 years to avoid runaway climate change.

For instance, as the Arctic ice cap melts, less sunlight is reflected. Seemingly dramatic changes in weather patterns including the melting of glaciers in Greenland and the thawing of the Siberian permafrost have at last convinced most business leaders that the time for action is now.

In Siberia, vast quantities of methane, an extremely potent greenhouse gas, are locked up in what used to be called permafrost regions in which it was assumed that the ground was permanently frozen. But areas that used to be frozen are now thawing, releasing methane and thus contributing to further warming and to further thawing, which releases more methane.