Human element of CO2 is 'tiny'
Carbon dioxide is not one part in every five million of the atmosphere but about 300 parts. The human contribution to CO2 is about 3pc so that makes the total nine parts in a million. However, Michael Job (Letters, March 10) is wrong to say that only CO2 has a greenhouse effect (by which he means only it absorbs infrared light).
Oxygen and nitrogen, which make up more than 99pc of the atmosphere, do absorb infrared, albeit not as strongly but there is so much more of it.
A greater greenhouse gas, both in its quantity in the atmosphere and its absorptive powers, is water vapour.
In total, the human element of CO2 is so tiny that any effect is also bound to be of the same order. In fact, the correlation between sunspot activity and temperature is very close, certainly very much closer than with CO2 levels, which presumably explains why global temperature has repeatedly been considerably higher than it is now, particularly during the mediaeval period and the well named Climate Optimum of 9,000BC to 5,000BC.
Michael says: "The notion that vast sums of money are being wasted on combating climate change is a myth, but even if it were true, it would be worth any amount of money to prevent the catastrophe which will occur if the boffins are right."
In fact, vast sums are being spent -- Kyoto has been calculated at $800m (€587m) a day -- and it is difficult to see why it would be worth any amount of money to prevent us enjoying an optimum climate, even if that were on offer. As my previous letters pointed out, it is simply wrong to claim that "the boffins", in general, support this scare. Indeed, even Professor Jones, the head of the British CRU (Climate Research Unit) which has led regarding this theory, has had to admit there has been no warming over the past 15 years and that it is cooler now than in the Middle Ages.
Perhaps the world has no real problems that require money?