The Reminder is making its archives back to 2003 available on our website. Please note that, due to technical limitations, archive articles are presented without the usual formatting.
Scientists have their own way of putting things. This is how Dr. Oerjan Gustafsson of Stockholm University announced the approach of a climate apocalypse in a recent e-mail from a Russian research ship in the Arctic Ocean. ÒWe had a hectic finishing of the sampling program yesterday and this past night. An extensive area of intense methane release was found. At earlier sites we had found elevated levels of dissolved methane. Yesterday, for the first time, we documented a field where the release was so intense that the methane did not have time to dissolve into the seawater but was rising as methane bubbles to the sea surface.Ó GustafssonÕs preliminary report, published September 23, is far more frightening than the current financial crisis. The worst that the financial crisis can bring is some years of recession. The worst that massive methane releases in the Arctic can bring us is runaway, irreversible global warming. Molecule for molecule, methane gas is 20 times more potent than carbon dioxide as a warming agent. However, since human activities do not produce all that much methane, concerns about climate change have mostly focussed on carbon dioxide. The one big worry was that warmer temperatures might cause massive releases of methane from natural sources. There are thousands of megatonnes of methane stored underground in the Arctic region, trapped there by the permafrost. If the permafrost melts and methane escapes into the atmosphere on a large scale, it would cause a rapid rise in temperature Ð which would melt more permafrost, releasing more methane, which would cause more warming, and so on. Fear of this runaway feedback is why most climate scientists (and the European Union) have set a rise of 2 degrees C in the average global temperature as the limit which we must never exceed. Somewhere between 2 and 3 degrees C, they fear, massive feedbacks like methane release would kick in and take the situation out of our hands. Unfortunately, the heating is much more intense in the Arctic region. The average global temperate has only risen 0.6 degrees C so far, but the average temperature in the Arctic is up by 4 degrees C. So the permafrost is starting to melt, and the trapped methane is escaping. That is what Dr. GustafssonÕs research ship found: areas of the Arctic Ocean off the Russian coast where ÒchimneysÓ of methane gas are bubbling to the surface. What this may mean is that we have no time left if we hope to avoid runaway global warming Ð and yet it will obviously take many years to get our own greenhouse gas emissions down. So what can we do? There is a way to cheat, for a while. Several techniques have been proposed for holding the global temperature down temporarily in order to avoid running into the feedbacks. They do not release us from the duty of getting our emissions down, but they could win us some time to work on that task without running into disaster. The leading candidate, suggested by atmospheric chemist Paul Crutzen, is to inject sulphur dioxide into the stratosphere in order to reflect some incoming sunlight. (This mimics the action of large volcanic eruptions, which also lower the global temperature temporarily by putting huge amounts of sulphur dioxide into the upper atmosphere.) Another, less intrusive approach, proposed by John Latham of the National Center for Atmospheric Research in Colorado and Prof. Stephen Salter of Edinburgh University, is to launch fleets of unmanned, wind-powered vessels, controlled by satellite, that would spray seawater up into low-lying marine clouds in order to increase the amount of sunlight that they reflect. The great attraction of this technique is that if there are unwelcome side-effects, you can turn it off right away. Starting now, we need a crash program to investigate the feasibility of these and other techniques for geo-engineering the climate. Once the thawing starts, it is hard to stop, and we may need them very soon.
