More on Global Warming

Ron enters the Global Warming debate and endorses the views expressed by Cyril Marsters

Dear Ray

It was interesting to see the 'nuclear/global warming' debate continuing in The Pump. I liked Peter Bodle's letter and agree with everything he said.

It seems that the average global temperature for 2009 was the fifth highest temperature ever recorded, and it would seem indisputable, that we have had some warming in recent decades. Despite the apparent drop since the peak of 1998, the last ten years have been the warmest on record although, within the limits of accuracy, it is probably true to say that there has been no further warming since the beginning of the century. Whether or not the warming is due to greenhouse gases and whether it will continue remains a little less certain. The recent cold spell cannot be taken as evidence that the world is cooling but it may be significant that it is not just a local effect for the UK. Extreme cold weather and/or below average temperatures have been experienced across large areas of the world.

A lot of the emphasis is on CO2 but there seems to be a tendency to ignore other greenhouse gases. Some people tend to joke about the gases produced by livestock (and humans) and by decomposition of organic matter, but methane is 23 times more powerful as a greenhouse gas than CO2. A UN report in 2006 found that livestock produced 18% of greenhouse gases, but World Watch, an environmental organisation, claimed that it was nearer 50%. One writer claimed that the livestock in this country was responsible for more warming effect than all the cars, but I have no idea as to the truth of that. Nobody is talking much about nitrous oxide either, which is generated from various sources and is ten times worse than methane.

Despite my personal scepticism, I am well aware that CO2 in the atmosphere can cause warming, and, whilst I would question that current concentrations are sufficient to cause the warming that has occurred, I have always considered that we should endeavour to minimise CO2 emissions world-wide and that we should endeavour to play our part provided it does not cause disproportionate economic consequences.

Many people were disappointed that the Copenhagen conference did not result in agreement for more positive action but I do not think we should be too despondent. It was, after all, the first attempt at a truly international conference to discuss matters relating to the world's future. There will need to be many more if we are going to save the planet from disaster. But it is not global warming that is the biggest threat, it is the ever growing population, it has just about trebled in my life time. What will happen if it trebles again in the lifetime of today's children? This growing population leads to ever increasing requirement for food and puts ever increasing demand on the earth's resources. It accounts for ever increasing pollution, global warming may be one consequence. When are we going to see governments recognising the root cause and when are we going to see an international conference on how to stop population growth?

I agree with Peter that Hybrid cars are of questionable value and I have queried the value of electric cars as a means of reducing CO2 before, especially the GM Ampera that we are hoping that Vauxhall will produce in the UK. I am sure the Ampera will be an interesting economical car that is pleasant to drive but it will be expensive and it seems unlikely that it will result in a significant reduction in CO2 when compared with a diesel of similar performance.

I found very little to disagree with in Cyril Marsters letter. I agree that there will be a great deal of CO2 generated in the construction and dismantling of nuclear power stations and in the mining and preparation of suitable fuel. I don't think anyone has attempted to quantify the amount with any accuracy but I have no doubt it would amount to thousands of tons of CO2, probably tens of thousands of tons, possibly hundreds of thousands of tons. But this has to be looked at in relative terms; according to my calculations a 4000MW coal fired station produces approximately 105,500 tons of CO2/DAY. I have no doubt that, over the thirty/forty year life of a nuclear power station it would result in far less CO2 in the atmosphere than that from a coal fired station.

I cannot disagree with those who would like to see us make more use of renewable energy. The problem with renewable energy in general is that it is not very intense so that it needs very large catchment areas and consequently very large expenditure. We now have thousands of windmills, 12,000, I believe, at a cost well in excess of £20bn, and they contribute less than 4% of our electricity consumption. The recently proposed hugely expensive wind farm the size of Norfolk off the east coast will make a bigger impact. Because wind is very inconsistent, however, it is surprising that there has not been more effort into harnessing the more consistent forms of energy such as tidal.

For those that are interested, I have come across a few more pieces of information relevant to global warming:

According to the German magazine Der Spiegel: Just a few weeks ago Britain's Hadley Centre for Climate Prediction and Research produced some new figures correcting the IPCC claim that there had been some warming since 1999. They stated that following some adjustment for naturally occurring events there had been no increase.

Professor Ken Caldeira, an ecologist from Stamford University and a contributor to the International Panel on Climate Change, recently conducted some experiments that showed that increasing CO2 levels in the atmosphere leads to an increase in the rate of plant growth if other environmental parameters are kept constant. Doubling the atmospheric CO2 concentration from the present 0.038% to 0.076% yielded a 70% increase in plant rate of growth. This does tend to show that there is a tendency for plant life to absorb more CO2 as concentrations increase, thereby making the planet partly self compensating, always providing, of course, that people stop cutting down the trees.

Nathan Myhrvold, a former colleague of Professor Hawkins and now ecology advisor to Bill Gates points out that our human ancestors thrived and developed when CO2 concentrations in the atmosphere were higher than 0.1%. Current levels are 0.038%. It should be remembered also that there is evidence that the British Isles had a sub-tropical climate at one time.

Professor Easterbrook of Western Washington University has pointed out that the temperature of the Pacific follows a cyclical oscillation. Currently it is in a cooling mode that commenced in 1998 and he suggests that the global temperatures are likely to follow, indicating a period of global cooling for two or three decades. (Seems rather unlikely but time will tell.)

Ron Watts