A letter in the Bracknell Standard of 4 December asked how we all know that global warming is a fact. Well all the independent scientific studies over the last 20 years say so (the latest, last week, was about the melting of the glaciers in Switzerland). Even David Bellamy has now stopped being a denier and his strange opinion in the past was never scientifically supportable.

The scientific studies, including the UN International Panel on Climate Change, base their evidence on measurement. For example: ice-core records show the variation in yearly temperatures, most glaciers on the planet are now shorter than before, the width of tree rings (including those that have been long dead and preserved in peaty bogs), corals (which like trees grow a new ring every year, bigger in warmer years than colder ones) and most strangely the pollen count of dead vegetation in mud at the bottom of lakes.

The really detailed measurements, however, have been made of the change in maximum and minimum temperatures at the same places all over the world every day for very many years. Readers will be familiar with the white slatted boxes standing four feet off the ground called Stevenson screens. These were designed 150 years ago and the instruments they contain provide daily readings of temperature and humidity. These prove it is getting hotter much too quickly.

The scientific community has been unanimous in its pessimism. They say it will soon be too late to prevent the removal of most human life on the planet. The key conference is in a year’s time in Copenhagen. The politicians of the world must take action to prevent runaway global warming for the sake of future generations.

David Young

The Green Party General Election candidate for Bracknell.