RE: The letter on November 25 headlined ‘History is perverted’ in which Eric Alexander talked about the history of the climate change debate, saying it was started by a handful of scientists around the 1960s. CLEARLY from Eric Alexander’s letter in the BFP, it is obvious that Eric has little knowledge of the history and physics of ‘greenhouse gases’.

It was the French engineer and mathematician Joseph Fourier who, in 1827, first identified the presence of gases in the atmosphere that kept the planet warm, without which humans could not survive.

In 1860, the Irish physicist John Tyndall reported that only certain gases through infra red radiation stopped the heat from the sun escaping back into space.

By far the most important of these ‘greenhouse gases’ is water vapour which accounts for around 95% of the ‘greenhouse’ effect. CO2 accounts for only 3.6%! The balance being methane and CFCs.

In 1938, inspired by rapidly rising temperatures during the 1920s and 1930s, a British meteorologist, Guy Callendar, suggested that the rapid temperature rise may be due to the increased burning of fossil fuels. Far from seeing this as an unqualified disaster as Eric Alexander does, Callendar saw it as being beneficial to mankind in supporting greater agricultural production and might delay the onset of the next ice age.

Scarcely had Callendar made his predictions, than the ‘little cooling’ arrived and global temperatures started to fall despite atmospheric CO2 concentration continuing to increase. The 1960s was the coldest decade of the 20th Century and despite the emergence of the environmentalist movement at the same time, there was a consensus amongst many climatologists that the planet was rapidly descending into the next Ice Age.

James Hansen was one of those who supported the cooling theory until temperatures started to rise again in the 1970s when politicians got involved.

Hansen quickly changed sides and became a warmist together with many others who had previously supported the global cooling theory.

The warming trend that started in the 1970s came to an end in 1998 and since then global temperatures have started to fall again. The Al Gore film An Inconvenient Truth is little more than popularist science fiction the content of which bears little resemblance to proven scientific knowledge.

If, as Eric Alexander suggests, this film caused politicians to act in a matter of urgency then that only proves the gullibility of politicians.

Anthony Weeden, Bockmer End, Nr Marlow