CO2, we’re told, is the knife at the throat of world climate. Methane has so far got much less press, mostly because there’s a lot less of it in the atmosphere. And just as well; methane is 23 times more potent in its greenhouse effect as the equivalent quantity of carbon, so even small quantities can mean big climate problems.
BBC2 are currently running a series entitled ‘The Power of the Planet’, presented by geologist, Dr Iain Stewart. In the episode aired last night, Dr Stewart visited the vast Siberian tundra, an area the size of the continental US. Here in the frozen wilderness, billions of tons of decayed matter is trapped in the permafrost. The frost, however, is losing its grip.
Dr Stewart and an Alaskan colleague carried out a vivid and unforgettable practical demonstration of just what is going on underneath the apparently lifeless Siberian landscape. They walked out onto a frozen lake, cleared off the covering snow and drilled a number of tiny boreholes into the ice below (around two feet in thickness). Click the clip below to view:
They then put a small flame to the neck of the boreholes – in each case, they exploded into flames, one blast actually knocked the Alaskan scientist off her feet. To see flames emerging from this seemingly pristine ice was both astonishing and terrifying. This is the front line of global warming. This area has seen temperatures climb by around 3 degrees C in the last 10-20 years. This is much faster than anywhere else on earth.
This profound temperature rise is unlocking the frozen matter in the permafrost, and material beneath the frozen lakes is now warm enough to begin decomposing. And as it does, so the methane bubbles upwards…
Methane escape in Siberia is now five times greater than previously estimated. It is contributing to a powerful ‘positive feedback’ mechanism, where escaping methane warms the climate, which leads to still greater methane production and release, which in turns feeds back into higher temperatures… Nobody can say for certain at what point a threshold could be crossed whereby this feedback process becomes a climatic runaway train.
What we are seeing most clearly is that the polar zones, north and south, are bearing the brunt of climate change, and have to date been major buffers against the most dramatic effects hitting heavily populated areas. If, however, the buffers cease to function and instead become major net contributors to global warming, then even humanity slamming on the brakes in terms of carbon output may be insufficient to prevent runaway heating. (for why this is something we really, really don’t want to have happen, see the article on Climatechange.ie entitled ‘Degrees of danger‘).