I’ve just returned from Finland which has had such a bitingly cold winter that I was able to take long walks on the frozen Baltic sea ice right outside Helsinki. The picture shows the view: that is not a snow-covered field in the foreground but the frozen sea leading back to the grand houses which rim Helsinki’s shore. At sea you meet people walking their dogs, skiing or taking a new short cut to work. If you stop them and chat (not what the famously taciturn Finns expect) they’ll tell you that this is the coldest winter they can remember and ask “whatever happened to global warming”
It is easy to forget about it on a cold winter’s day but, strangely enough, the freezing cold in Finland also enables you to spot some signs of change, quite troubling ones which suggest that the Arctic is busy plotting its revenge on the rest of the world. Walking across frozen inland lakes you can see, here and there, odd patterns of bubbles trapped in the ice. These are spots where methane has been bubbling up from the lake. In summer, when there is no ice, you can see bubbling in ponds all over the Arctic and if you hold a match over a busy spot (very carefully) there will be a brief puff of fire as the methane burns.
Arctic lakes like this one in Nunavut are growing sources of methane Picture: Alun Anderson
I was thinking about this when I got home and found a paper in Science which had been published while I was away. A group of scientists used satellites to measure the release of methane gas from the Arctic, compared to the rest of the world, and I didn’t like what they had found. A couple of years ago the amount of methane in the atmosphere began to unexpectedly grow. The new research helps track down why.
Most methane still comes from tropical wetlands and the vast areas of paddy fields where organic matter rots away in wet conditions. But they found that the amount of methane coming from the Arctic leapt by over 30 per cent in the short period between 2003 and 2007. Arctic methane is still a small percentage of the world total but its very rapid growth is disturbing. Methane is a very powerful greenhouse gas. When methane rises into the atmosphere it absorbs heat coming up from the Earth below and radiates it back again. As an extra blanket around the planet it is over 20 times more effective than carbon dioxide, the greenhouse gas that comes from burning fossil fuels. The only good thing is that methane vanishes from the atmosphere in just nine years instead of staying up there for centuries. Methane delivers a powerful but short warming punch.
Methane is released from the Arctic when the long hours of summer sunlight come around and the top layer of the tundra thaws and begins to ferment. The amount of methane is rising fast as the Arctic is growing wetter and warmer in summer. Climate change is coming quickly in the Arctic because the sea ice is melting and setting a feedback loop in train. The black water that is replacing the bright white ice soaks up sunlight. As the water warms it melts yet more ice, which soaks up yet more heat. The warmer sea warms the air which spreads over the surrounding land. The result is warmer, wetter tundra that bubbles out more methane, which warms the atmosphere still more, going round and round in a second runaway feedback loop.
When I was researching After the Ice: Life Death and Geopolitics in the New Arctic, I learnt that there is enough carbon in the now frozen tundra to push up global temperatures by 7 degrees. The permafrost cannot thaw quickly but it is scary to learn that once it really gets going it will just go on adding more and more warming for hundreds to thousands of years.
That is why these numbers showing a big rise in Arctic methane get me nervous. We are starting a feedback loop in which a potent greenhouse gas is going to be produced in ever larger amounts, warming the whole planet. Still, while this cold winter continues I don’t think too many politicians are going to share my concerns about our long term future.