The cyclone that devastated the Pacific island of Vanuatu in March, the most severe ever recorded in the region, highlighted again the very likely connection between extreme weather events and global warming. This disaster could also push the issue of ‘climate engineering’ into greater prominence, since it can appear to be a quick, cheap technical fix to climate change. The credibility of climate engineering was given a boost by the recent call of the prestigious National Research Council in the USA for more research on the topic.
This recommendation is likely to be seized on by the Republican-dominated Congress, as well as by ultra-right think-tanks which have long advocated climate engineering as an answer to rising global temperatures. It is not explained, of course, why they think such drastic action is necessary, when these think-tanks either deny the existence of human-induced climate change or hugely downplay its significance.
Before looking at the arguments, we need to define what is meant by climate engineering – or geo-engineering as it is sometimes called – since there is not common agreement on this. There are two aspects: the removal from the atmosphere of carbon dioxide, the gas that mainly drives global warming; and solar radiation management, which attempts to reflect back into space some of the sun’s radiation, thereby reducing temperatures. Carbon dioxide removal is not considered by some to come under the heading of climate engineering, possibly since it poses fewer risks than solar radiation management.
Most carbon removal ideas, though, are not risk free. A big problem, because of its great dangers to health, is the safe storage of the gas for an indefinite period of time. For example, when there was an unexpected release of carbon dioxide from a lake in Africa, due to natural causes, thousands of people were suffocated when they were enveloped in a cloud of gas that rolled across the countryside.
Some proposals which have been put under the rubric of climate engineering are benign, such as reforestation, since trees are a major sink of carbon dioxide. However, the danger here is that the impression is given that such measures can tackle global warming, and take the pressure off action to cut greenhouse gas emissions. Unfortunately, the time has long run out when reforestation, although necessary, could alone act with the scale and speed necessary to make a meaningful difference to warming.
Solar radiation management poses a much greater danger than carbon dioxide removal, and there are various proposals being put forward, some more threatening than others. Some, like ‘cool roof’, involve using light-coloured roofing materials that will reflect rather than absorb the heat from the sun. More dangerous are the proposals to seed the atmosphere with sulphur particles to mimic the action of a volcanic eruption that reduces global temperatures. This effect was first noticed after the Krakatoa eruption in South-East Asia in the 19th century, the biggest in recorded history.
More recently, after the Mount Pinatubo eruption in the Philippines in 1991, thousands of tonnes of sulphate particles were thrown into the atmosphere and quickly spread, reducing global temperatures by a few tenths of a degree for several years. This fall is significant in global warming terms, since small changes can have big impacts on the environment. So far there has been an increase in temperature of only three-quarters of one degree Centigrade above pre-industrial levels. Nonetheless, there is rapidly increasing evidence to link this to extreme weather events like hurricane Katrina, which devastated New Orleans and the Gulf of Mexico in 2005.
Scientists from the National Center for Atmospheric Research in Colorado, USA, writing in Geophysical Research Letters, studied the effects of the Pinatubo eruption and found that there was a marked decrease in rainfall. They concluded that any attempt to inject sulphate particles into the stratosphere could have a disastrous effect on the earth’s water cycles, leading to drought and famine. Other risks linked to seeding the atmosphere with sulphate particles could be the depletion of ozone, a gas that protects us from skin cancer caused by solar radiation.
If solar radiation management was used for a significant time, while greenhouse gas emissions continued to escalate, and then was suddenly cut off, there could be a very rapid rise in temperatures, causing even greater destruction than that produced by a more gradual change. Also, the acidification of the oceans, linked to increasing concentrations of carbon dioxide, would not be addressed at all by a solar radiation management approach, potentially further damaging marine life and ecology and destroying coral reefs.
Another proposed solar radiation management approach is to construct mirrors in space to reflect back solar radiation. Although less likely to be attempted due to the high cost, this would have the same drawbacks as using sulphate particle aerosols, if its use masked an increase in carbon dioxide emissions. If the mirrors failed for any reason (mechanical failure, terrorism, lack of financial resources to maintain them, etc), there would be the danger of a very rapid and destructive rise in temperatures.
A danger common to all the solar radiation management techniques is that they could coincide with a natural volcanic disaster that could not be predicted by any computer model. The result would be to compound the cooling effect of the climate engineering technique with the fall in temperature caused by the volcanic ash, with potentially devastating consequences.
One of the biggest attractions of climate engineering to the capitalists is the relatively low cost. The cost of cutting emissions to safe levels was estimated by the Stern review, commissioned by the last Labour government, at 1% of economic output per year for 40 years. (Nicholas Stern, Report on the Economics of Climate Change, 2006) On a world scale this would amount to approximately $400 billion a year. Some estimates of the cost of solar radiation management have been put at a fraction of this, a few hundred million dollars a year, frighteningly putting them within the reach of irresponsible billionaires with a bee in their bonnet. Bill Gates and Richard Branson have already sponsored research in this field. In Russia, a climate sceptic and senior adviser to the government has experimented by spraying sulphur particles from a helicopter.
No reputable scientific body has advocated climate engineering as an alternative to reducing greenhouse gas emissions. The ones that advocate research in the field, such as the Royal Society in Britain or the US National Research Council, see it as buying time while action is taken on the fundamental cause of global warming. The danger of this approach is that the capitalist governments that are already extremely reluctant to spend any significant money on reducing warming will jump at climate engineering as a cheap alternative. Going down this road could, potentially, be almost as dangerous as global warming itself. Removing the fundamental cause of the problem means removing the profit-driven capitalist market system. The longer this task is delayed, the worse will be the prospects for the environment.