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The Scientific Alliance's Martin Livermore says carbon emissions cuts will not reduce the current risk of floods in the UK, but proper flood defences will. Rather than commit billions in an attempt to control our weather, the UK government should invest in better flood defences to avoid another Tewkesbury
European Union member states and many other countries seem committed to an unprecedented global initiative to cut carbon emissions and limit the extent of global warming, based on scientific advice from the International Panel on Climate Change (IPCC).
But the major changes to how we generate and use energy will not come for free. Given the burdens this will place on economies round the world, it is legitimate to ask two questions: Do we really understand what drives the climate and, if so, can we really control it? Unfortunately, such reasonable questions are all too often dismissed out of hand as emanating from paid lackeys of “Big Oil” or from “mavericks” who just don’t deserve to be taken seriously. For the record, no-one is paying me to write this (more’s the pity). As to the second category of questioner, the reader is free to form their own judgement.
The view of the IPCC is that climate is changing and that Mankind’s use of fossil fuels has become the primary driver in recent decades. That climate is changing is indisputable; the big news would be if it was to be stable. Most people will have experienced a range of extreme weather in their lifetimes, overlaid on mid-term trends: a rise in average temperatures in the first three decades of the twentieth century, a small fall from the 1940s to the mid-70s and, since then, gradually increasing temperatures, mainly in the northern hemisphere and peaking so far in 1998.
At the same time, with increasing industrialisation has come a vast expansion in energy use, by far the greatest part coming from fossil fuel sources. It seems certain that this has contributed to a steady rise in the level of carbon dioxide in the atmosphere, from about 280 ppm (parts per million) in pre-industrial times to around 380 ppm today.
Other things being equal, this rise in the level of a trace gas (still less than 0.04% of the air) would be expected to raise temperatures. The real question is by how much. The IPCC bases its conclusions on highly sophisticated computer models which aim to capture the vast complexities of global climate and project the outcome of continued carbon dioxide level increases over many decades.
There are two intrinsic problems with this. The first is the assumption that the understanding of the “natural” climates system is so good that any human fingerprint can be unambiguously detected. But modellers readily admit that they cannot properly deal with the complexities of clouds, which can have a major impact. There are other respectable scientists who point towards an apparent link between climate patterns and solar magnetic activity. The point is that the modellers’ assumption is not necessarily valid.
The second problem is that, if carbon dioxide is the main driver of change, certain patterns should clearly emerge. One is that the poles should warm faster than the tropics. The north pole is indeed showing this trend, but temperatures across the Antarctic have actually fallen. Another is that the mid-layer of the atmosphere – the upper troposphere – should be warming faster than the Earth’s surface. It isn’t.
The objective conclusion to draw is that human-driven climate change is a plausible but unproven hypothesis. Nevertheless, governments around the world seem prepared to put in place hugely expensive programmes of emissions reductions which, if the Kyoto protocol is any guide, will not even be adhered to, let alone influence global temperatures.
If the IPCC is right – and they could be – and if the international community met emissions targets which are far, far tougher than the Kyoto protocol demands (a big if), then the result would be some reduction in average temperatures reached much later in the 21st century. In the meantime, average sea levels have been rising steadily over the last century. Coastal communities will inevitably have to adapt to this. Also, major climatic fluctuations, particularly El Niño/La Niña in the Pacific, continue to influence regional weather patterns. Their causes are not understood and they are not fully predictable.
Against this backdrop, adaptation to whatever the climate throws at us is essential. Some regions are vulnerable to drought and some places are flood-prone. Whether we cut emissions or not, protecting communities from extreme weather must be a priority. Prosperous countries do this already, but floods (for example) may still lead to major economic loss (for the simple reason that people build in the wrong places). Rather than commit billions in an attempt to control our weather, the UK government should invest in better flood defences to avoid another Tewkesbury.
Adaptation and protection is essential. Emissions cuts will not reduce flooding risk in the here and now, whatever effect they may have in 2050. Proper flood defences will. Life is all about priorities and it seems clear to me that we are in danger of setting the wrong ones.
The author is director of the Scientific Alliance, which promotes informed debate on environmental issues. For more information, see www.scientific-alliance.org