The UK Meteorological Office has just announced that 2012 was officially the second wettest on record (with records having been kept since 1910). Not only this, but there have been a number of exceptionally rainy years recently: the record was in 2000, followed by 2012, 1954, 2008 and 2002. How the data is collected and analysed will, of course, affect the exact figures, but it does seem clear that north-west Europe is experiencing a run of very wet years.
The reasons for this are keenly debated, but the Met Office and others are suggesting that the increased frequency of such wet years over the past century is a consequence of the broader climate change trends during this period. On the face of it, this is not an unreasonable conclusion, since a slightly warmer atmosphere is capable of holding larger amounts of water vapour. At one time, this would perhaps have been just an interesting observation and possible clue to future trends but, with climate change being the defining environmental issue of the early 21st Century, it is now also put forward to justify the need to take urgent action to reduce human impact on the climate.
The enhanced greenhouse hypothesis, which has become the prevailing orthodoxy, predicts that rising levels of atmospheric carbon dioxide will warm the air, which then carries more water vapour. Since water vapour itself leads to more warming, even more carbon dioxide is released into the air by out-gassing from the oceans, leading to a self-reinforcing cycle of temperature increase. This postulated positive feedback mechanism leads to the projection of a much higher climatic sensitivity factor – the temperature increase resulting from a doubling of carbon dioxide levels – than the known absorptive capacity of CO2 alone would give.
The outcome is not just of scientific interest: if such positive feedback does indeed occur, it could indeed make the difference between a modest and largely beneficial increase in average temperatures over the next few centuries and the potentially damaging, disruptive and even catastrophic effects which some of the more alarmist commentators project. This is the scientific and philosophical underpinning of demands for a radical cut in emissions of carbon dioxide, in particular by slashing use of oil, coal and gas. It is, for example, what led activist scientist James Hansen to make his infamous ‘trains of death’ remarks when talking about coal-fired power stations (Coal-fired power stations are death factories. Close them).
But radical re-engineering of our energy generation is not the only way to deal with the possible threats of climate change. As well as mitigation by limiting emissions, adaptation is also possible. For now, the emphasis is firmly on mitigation, with international negotiating efforts continuing to grind away in an attempt to come to a binding agreement on emissions reduction by all countries. But a dispassionate look at this suggests strongly that these energies are being misplaced.
As I have said many times (and I am not alone in this) there is no realistic prospect of overall greenhouse gas emissions declining unless the major emerging economies (particularly China) stop developing. The consequences of this would be socially and politically devastating for the world. Even if rich countries were to pay for ‘clean’ development, there would be a pause of a decade or more while nuclear power stations began to be built on a large enough scale to enable rapid growth to restart. Massive rollout of solar and wind generation alone could not provide reliable grid power.
In the meantime, costly programmes to reduce emissions in Europe (now joined by California, with its new emissions trading system) will do little other than to reduce competitiveness. Whether or not you consider the enhanced greenhouse effect to represent a real threat over the coming century or so, it is difficult to avoid the conclusion that current mitigation efforts are a costly waste of resources.
However, the alternative is not simply to do nothing (at least until reliable, economic sources of renewable energy are developed). Droughts, flooding, hurricanes and other natural disasters will continue to be visited upon parts of the world whatever future trends there may be in global or regional climate. Some areas will be more vulnerable than others because of their geography, population density and prevailing weather patterns.
The miseries suffered by people in flooded parts of the UK are mostly minor compared to what some countries have to endure, but they are nevertheless disruptive and costly. Investment in flood defences would achieve much more over the next few decades than a similar amount spent on emissions reduction policies. Flooding represents a real existential risk to some other countries, because they are low-lying. The Netherlands would not exist in its current form if not for the massive sea defences built and improved on over the years (neither would large chunks of East Anglia). New Orleans would not have been devastated by hurricane Katrina if levees had been raised. Countries such as Bangladesh could be similarly protected from repeated flooding.
Regions prone to drought can also be better equipped to deal with the consequences, via water storage schemes, irrigation systems and the breeding of stress-tolerant crops. Many parts of the Caribbean and south-east Asia could avoid some of the worst impact of hurricanes and typhoons via warning systems, evacuation plans and shelters. Economic losses are inevitable, but at least mortality could be minimised.
Allowing for the projected impact of climate change may mean making flood defences higher or reservoirs bigger, but this is work which will need to be carried out in any case. Whatever the rate may be, sea levels will continue to rise until the next Ice Age (which will provide a much severer test of our species’ ability to survive than global warming is ever likely to do).
We tend to forget that the UK was part of continental Europe until only about 10,000 years ago. In another hundred centuries, the world will look very different again and, if humans still survive, it will be because we and our descendants have adapted to whatever Nature throws at us.
The Scientific Alliance
St John’s Innovation Centre
Cowley Road
Cambridge
CB4 0WS
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