IN HIS letter, Objective evidence or we're in trouble (October 8), JimThomas produces no evidence (objective or otherwise) in support of his belief in man-made global warming. Instead what he does is to take the unscientific approach and do two unforgiveable things.
Firstly he attacks anyone who disagrees with his belief as being, in his own words "scientifically unqualified individuals with hidden personal agendas". I can tell him that I am a retired physicist, with no personal agenda and that as a result of years of study of the physics of the climate, I am sceptical of man-made global warming. The climate is driven by the laws of physics and so I judge that I am more qualified than Jim Thomas to understand climate change.
Secondly he appeals to authority by suggesting that because NASA and the Royal Society say man-made global warming is real, then it must be true. What has to be realised is that both these organisations receive vast amounts of money from their respective governments and so are not in the position of being objective. And, of course, what both organisations say is only the vew of a handful of people. He quotes the Royal Society as concluding that it is "highly confident that greenhouse gas emissions are causing global warming." So the Royal Society is not providing any scientific evidence, just a belief that it is confident in. That doesn't sound like science to me - but I'm an old fashioned scientist who relies on evidence, not beliefs.
An objective view of the science of the climate shows that the climate has changed due to natural processes for over 4 billion years and as the climate is an unstable and chaotic system, it always changes. The evidence is that we are currently in a cooling period, driven by little understood processes involving ocean circulation patterns (it's the oceans that store and release vast amounts of energy received from the sun) and the cyclical behaviour of the sun itself. What we are told by government bodies (propaganda) is based on ill-defined computer models which make assumptions so that global warming is awlays predicted. Computer models are not science and are not evidence of anything other than the ability of the computer modellers to write computer codes that produce the outcome they want.
If Jim Thomas can produce evidence to support his belief in man-made global warming, let him produce it to be discussed. In the meantime I suggest he goes back to his government-funded job of lecturing in chemistry and also learn a bit about how science works, which should be based on hypothesis supported or refuted by evidence, not on belief or opinion.