It surprises me that nobody has mentioned this paper yet, from Geophysical Research Letters.
Perhaps it is not as significant as I imagine it to be.
The research team has reported the extraordinary warming of the soil in Svalbard during the winter of 2005-2006. The abstract mentions in passing that such events, if they continue into the future, will have ‘potentially damaging’ effects on permafrost. Why does this matter?
The matter at issue is methane. Looking recently at the surface temperature anomalies over huge areas of Central and Northern Siberia, with numbers exceeding +5C for sustained periods, there is an implication that what was observed at Svalbard (albeit in Winter) also holds true for very large areas where permafrost currently exists. Just last year, researchers at the University of Fairbanks, Alaska, reported that methane release from permafrost degradation and the creation of lakes in tundra might be as much as five times higher than previously estimated. I cannot find any current numbers on atmospheric methane, or on emissions levels from Siberia, and we may well have to wait until the CDIAC or another agency publishes its annual summary early next year before we have the actual numbers. My guess is that they will show a rise in concentrations.
It is important to get this into perspective, though. At the moment, most methane comes from wetlands, including rice fields, with another large chunk coming from industrial activities and processes. Contrary to popular belief, cattle are only (debatably) responsible for a smaller percentage of the total than these two. Total emissions from permafrost degradation to date is estimated to be only a few percent of the atmospheric total. So an increase of several tens of percent in permafrost emissions is only going to have a relatively small impact on the big total – for the time being.
It is also important to recognise that this year in Siberia may be uncharacteristically warm, and future temperatures will be less extreme. Irrespective of this, the mean regional temperature curve is still strongly upward over the past twenty-five years. We cannot assume that similar anomalies to 2007 will persist into the next five years; we can imagine that they might, though.
But what appears to be happening in the far North could arguably be described as a ‘phase change’, comparable to the change in the oceans between water and ice. Already, large areas of previously stable permafrost have been effected by the warming of the far North. This year may well produce record large losses in permafrost, though in the absence of on the ground observations, this may have to be inferred from secondary observations and await confirmation when the observing stations are re-established. Though the land surface will undoubtedly refreeze soon, in response to the onset of the Arctic Winter, come the thaw period, we should expect lakes to form more quickly, and methane to be released for longer and over larger areas, as the phenomenon of Polar warming persists and amplifies.
By far the largest feedback going on in the Arctic relates to the ocean-ice albedo problem which has been referred to several times over the past weeks. But here is another example of a persistent feedback which will find its effects in the global atmospheric GHG forcing, and thus feed back, both locally and globally. The effect may be small for the time being, and there is unlikely to be a ‘clathrate gun’-type event, but it is adding to the existing system, and at a rate which is greater than anticipated by the literature supporting the estimates of the IPCC AR4.
OTOH, the recent warming of the region will mean that life will be a lot easier for the new pioneers who are soon to head up to the Arctic coast to start building ports for the Northern Sea Route traffic, which is sure to become a regular feature in the coming years.
Stay warm, now…