Soapbox

Global Warming and Wind Turbines

The justification for the introduction of wind turbines is primarily the potential they offer to produce electricity with no pollution, especially no carbon dioxide because of its potential to cause global warming. Before discussing the merits of wind turbines it might be appropriate to review global warming and, perhaps, reiterate some of the points I made in a previous issue of the Pump. Certainly it does seem as though some global warming is occurring and without doubt the increase in the proportion of greenhouse gases in the atmosphere has the potential to raise the Earth's surface temperature. It is argued that because the proportion of carbon dioxide in the atmosphere has increased, and it is a known greenhouse gas, the global warming that has occurred over the last 140 years is due to that, but there is a danger of putting two and two together to make five.

Over the last 140 years the CO2 in the atmosphere has increased from 0.028% to 0.0368%, a difference of 0.0087%. Those scientist that claim that this is the cause of global warming need to show that this rather minuscule increase in the proportion of CO2 in the atmosphere is capable of producing a measurable increase in global temperature. The truth is, however, that the whole barrowload of scientists who make this claim cannot say this is so with any degree of certainty and some element of doubt remains as to the contribution these greenhouse gases have made to global warming and how much is due to other factors such as solar activity. Furthermore it is an assumption, albeit probably a fair one, that the increase in CO2 is due to the burning of fossil fuels, but it is an assumption nonetheless. There are other sources of CO2 and other possible explanations. Without significant interference by man, climate variation over past millennia has been far more dramatic than the small changes observed in recent decades. Contrary to popular belief the average temperature of the British Isles has hardly changed at all in the last 140years and global temperatures have increased by no more than 1C. Average global temperatures, it is claimed, can now be determined with an accuracy of plus/minus 0.15C, but, bearing in mind the hourly variation and geographical variation that occurs daily such a claim lacks credibility to my mind and they surely could not achieve that level of accuracy 140years ago? Thus this small increase in global temperature is of the same order of magnitude as the accuracy with which global temperature can be measured. It is possible also that such increase as may have occurred is part of the continuing cyclical variations that have been noted over past centuries. Certainly global temperature has never been constant.

Having said all,this,, because there is a strong possibility that further increase in atmospheric CO2 will result in further global warming ,then it is prudent to try and limit the generation of CO2. Any measures to do so, however, should be carefully weighed in terms of the benefits and the disadvantages and, to be worthwhile, must be adopted on a worldwide scale. I do favour the utilisation of renewable energy sources such as wind power and solar energy but these sources are of a low intensity, their beauty, however, is that they are widely and freely distributed and should be utilised at the point of use. Endeavouring to build wind or solar power stations and then go to the trouble of expensive distribution is, I believe, the wrong approach.

The CO2 emissions from the UK are estimated at about 2% of the global total and the emissions from the UK electricity industry is of the order of 0.5%. 300 Swaffham sized wind turbines could replace one conventional power station on the days that the wind was blowing sufficiently strongly. It would take thousands of similar turbines to produce a 10% reduction in the CO2 emissions of the UK electrical power industry and the effect of these thousands on total global emissions would be negligible.

In his letter to last month's Pump Nigel Tuffnell used emotive words by linking the risk of flooding in Norfolk with the building of wind turbines in Norfolk and tried to equate the environmental intrusion of wind turbines on the one hand with the environmental intrusion of sea defences on the other, but the truth is that thousands of Swaffham type wind turbines in Norfolk would make no difference whatsoever to the need that may arise for improved sea defences.

Nigel also poured scorn on my suggestion that wind turbines represented a threat to birds by claiming that the machines in this country rotated so slowly that the only threat they posed to birds was the same as that of any other stationary object. It is true that the Swaffhan type of turbine does rotate slowly. The maximum speed of that machine is 22 rpm, at this speed it takes almost a full three seconds to complete one revolution. Unfortunately, because of the large diameter of the rotor, even at this speed the rotor tip is travelling at 170mph - hardly a stationary object. Furthermore Nigel claims that beauty is in the eye of the beholder, many would claim that the form of these wind turbines might be regarded as aesthetically pleasing, even beautiful, but to describe these monsters, visible for miles, as picturesque is stretching things a bit. He agreed that one turbine was of limited value and that normally we would need to build a wind farm but, whilst one wind turbine may not be seen as a major eyesore by some, maybe even two or three - but three hundred? Or three thousand?

Ron Watts