Picture: 123RF/TOMAS1111
Picture: 123RF/TOMAS1111

Oh dear, yet more nonsense of the imagined dangers of rising CO, now described as a “beast”! (Carbon dioxide is a bigger beast than scientists thought, January 15).

Some new computer models show that rising CO will cause dangerous warming. The problem for these alarmists is that in the past their models predicted far more warming than actually happened. If they had looked at the real world, they would see that over the past 550m years, where CO has averaged about 2,000 ppm, it has never been seen to drive global temperatures.

CO is a weak greenhouse gas and in a test tube should have a small warming effect. But the real climate system is immensely complicated and no such warming effect has been seen. This might be because of overlap with more important greenhouse gases, especially water vapour, or because of negative feedback.

During the worldwide medieval warm period, about 900-1200 AD, temperatures in all five continents were rather higher than now while CO was lower than now (280 ppm compared with 412 ppm now). This is proved by more than 1,000 scientific studies and a great mass of historical record.

Both the medieval warm period and the present warming seem to have been caused by high solar activity (emission of charged particles), and have nothing to do with CO.

Our planet has suffered a CO drought over the past 5-million years or so. Humanity, purely by accident, has ended it by burning fossil fuels. This has had a wonderful beneficial effect on plant life and is greening the Earth. CO is a safe, clean, natural, life-giving gas.

Andrew Kenny
Sun Valley