Clark Cross (Letters, 1 October) repeats three of the many myths put about by those unwilling to face the reality of global warming. He is wrong about all of them.
Firstly, he claims “1991 Mount Pinatubo … spewed out more greenhouse gases … than the entire human race … in all its years on earth”.
In fact, Pinatubo is estimated to have emitted 0.05 gigatonnes of CO2, compared with about 35 gigatonnes per year by humans. The total CO2 emitted by all volcanoes annually is less than 1 per cent of anthropogenic sources.
Secondly, Mr Cross misinterprets the IPCC statement on volcanic cooling. Volcanic activity is unpredictable and, therefore, forecasts of future warming cannot accurately include their impact. But since that impact is small, the resulting uncertainty is small.
Thirdly, Mr Cross claims “the world has not warmed for 17 years”.
That is wrong. The world continues to warm, though rather more heat than previously has been absorbed into the oceans recently, so that surface warming has slowed a little.
The real puzzle is why, at a time when it has never been so easy to access reliable information, so many people still cling to comforting falsehoods over important global warming issues.
But that is a question more suitable for psychologists to answer than climate scientists.