Friday, 8 June 2007

The Turbulence of Climate Change

Following on a little from my posting about the G8, I remembered I wanted to write something about the histoy of climate change. Back in April of this year, there was much in the British media about whether climate change was a problem or not and certainly whether it was an issue to the scale as it has been presented in recent decades. I hear people say that it is not as grim as some specialists make out.

Part of the problem seems to be that different processes are going on. The depletion of ozone in the sky (excess ozone created by cars at street level is another problem but does not help) means more harmful UV rays penetrate to Earth and you cannot contest this when you are sunburnt through your clothing in Australia. On the other hand CO2 and particulate pollution are putting a thick layer around the Earth which prevents the rays bouncing back off (and this is yet another problem from what would have happened in terms of a nuclear war in which the material thrown into the atmosphere would have blocked sunlight reaching Earth leading to a so-called 'nuclear winter', an artificial ice age) and the Earth would heat up in the way that Venus, surrounded by thick cloud does, the so-called 'greenhouse effect' (the rays bounce back off the glass rather than escaping and so keep more heat inside than, say, in a canvas tent). This has knock-on effects, notably the rise in sea level as ice caps melt and in turn this shifts various ocean currents. In the UK global warming will have mixed effects as it will mean wetter weather (warmer air can carry more water) but our climate would become more like continental Europe as the Gulf Stream coming up from the Gulf of Mexico warms the UK and Eire a great deal and we would lose this as it will be pushed farther South by colder currents coming from the North Pole as ice melts) and we would move to a colder current as they experience in Belgium and the Netherlands. In parts of England it rarely drops below -2oC in Winter whereas Belgium often experiences -10oC in the same period. So it is not a simple pattern. Some people say, however, that it is all part of the natural cycle of the world and by implication, nothing humans do can prevent such a change.

My argument is simply, that it does not really matter what is causing climate change, pollution of the air, soil and water, in whatever form is bad in itself. With the emphasis on climate change people have forgotten the dead lakes and forests of Scandinavia killed off by pollution. They forget the immense soil erosion in parts of China which is making them uninhabitable. These reasons alone are enough to warrant cutting emissions and these are things known about for decades already.

Putting that aside, the history of the world, even in the last 2000 years has been one of climate change, something many people on both sides of the argument forget. At the time of the Ice Age you could walk around what is the North Sea (off the East coast of the UK). In Roman times water levels rose and the Zuider Zee which had been land, because sea (it has been reclaimed by the polders created in the Netherlands). In the year 1000 Greenland actually lived up to its name and cereals were grown on it by Viking settlers, something that is impossible today. In contrast in the 17th century the Winters were so cold that 'frost fairs', with fires lit, were held on the frozen River Thames in London and the sea offshore also froze, something impossible nowadays. In the 1970s there was fear that we were coming to the end of the 'inter-glacial' and would be plunged back into an ice age, a vision revived in the 2004 movie, 'The Day After Tomorrow'. I put these points in to show that there is an additional element and not to assume that we are simply marching towards an overheated planet caused by pollution. We need to do things, pay attention to the climate, and in the meantime cut down polluting anyway, because it is going to kill a lot of things before the greenhouse effect or the next ice age comes fully into effect.

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