SIR - Having watched (twice, I was so astounded) the TV documentary The Great Global Warming Swindle' it became increasingly clear through the programme that everything I and countless millions of people have learned and accepted over the last decade or so supporting the theory that man is causing global warming is complete rubbish!

Anyone who saw this astonishing documentary saw irrefutable contributions from many eminent scientists outside the main body of opinion concluding that global warming is in fact ultimately controlled by the sun and the waxing and waning of its power at various periods of time.

An even more amazing fact which emerged was that warming occurs 800 years before CO2 increased are noted, which obviously means CO2 does not lead global warming - it's the other way round.

In any case, the amount of CO2 in the atmosphere is apparently so infinitesimal (0.054 per cent) that it is unlikely that it could ever be a major factor.

I have found all this information to be a revelation and it has completely changed my thinking, but why have we not heard any of it before? The man-made global warming theory was seemingly greatly helped in its development by Mrs Thatcher, who was determined to prevent Britain ever again being blacked-out as during the miners and electricians strikes which brought down her predecessor Ted Heath's government. She also didn't trust the Middle Easts control of oil.

She gave large amounts of finance to groups of scientists to enable them to try to prove that burning fossil fuels was causing global warming and that we needed to switch to a cleaner source of power.

Now there is huge global industry to try to mitigate the supposed effects of burning fossil fuels and to find alternative methods of power and propulsion. I suspect that many of them are probably well aware of the natural causes and will be racking their brains to think how best to refute it.

DEREK BADDELEY, Malvern.