He argues that water vapour makes a bigger contribution to global warming than CO2 and that, anyway, there are only tiny amounts of CO2 in the atmosphere. Both statements are correct, but miss the point.

Firstly, there is no doubt about the important role played by water vapour in global warming. Indeed, the IPCC reckons it contributes 60-80 per cent of the total effect. But, without any global warming at all the Earth would be at least 30 degrees C cooler than it is now and would be uninhabitable. What we are worried about today is the increase in global warming that’s caused by our activities. As far as this increase is concerned, CO2 is the major culprit.

Secondly, it’s true that CO2 makes up less than 0.04 per cent of the atmosphere. But, just because it’s a small quantity doesn’t mean it doesn’t have a big effect. After all, all the trees and plants that we see growing around got all the carbon they need from this small amount in the atmosphere.

Finally, there have been experiments linking cloud formation to cosmic ray activity. These have been done to see if this is a possible mechanism for the well established, but small, effect of solar activity on the Earth’s climate.

The atmosphere is a complicated system with many different parts. It would take a much longer letter than this to even attempt to run through all the details.

However, global warming is also a political issue and one of the main weapons used by those who would prefer not to face the implications is to sow doubt about the science. This is the same tactic used by the tobacco companies in the 1960s. It is therefore disappointing that a Liberal Democrat councillor should be giving succour to climate change deniers in this way. I doubt it will please very many of his party colleagues.

Andy Sharp

Prospective Labour County Council candidate for Falsgrave and Stepney

Alexandra Park

Scarborough