Here is an interesting essay from a computer programming expert who seems to know a bit about computer climate models.
Big Climate's strange 'science'
Would you trust a software engineer to build a bridge?
By John Atkinson → More by this author
Published Thursday 14th February 2008 11:55 GMT
Comment I had to chuckle to myself reading a letter here at The Register, recently.
"David Whitehouse - although a respected scientist - is still only one voice and his speciality is astrophysics not climate," wrote a reader. This is one of my greatest concerns about so called climate science. Climate science is a very, very new field. So new, in fact, that it has had little chance for its assertions to be tested.
For example, climate models are being developed with very little ability to test out of sample. Furthermore, the climate science bandwagon has come about solely because of supposed anthropogenic climate change, which means that their funding is intrinsically tied to climate change happening and being man-made. A more self-interested group I could not find anywhere, even looking at the researchers who were paid by big tobacco companies to tell us cigarettes are safe.
The scientists who interest me in this field are those who can draw on the experience of a lot of people who have come before them. And uniformly in these areas I find scepticism. People who write mathematical models of complex systems for a living tend to find the climate models very unconvincing. Geologists find the arguments very unconvincing. Engineers find the arguments unconvincing. And astrophysicists find the arguments unconvincing.
Why? Well the answers are clear.
The climate models seem to be largely driven by over-fitting to a small sample set and positive feedback. The small sample set - at most 30 years of accurate data - might be enough to try and predict one or two years, but 50 year predictions? Ignoring the biggest effect on global warming - water vapour - is surely going to cause problems.
Positive feedback in engineering invariably results in unstable systems - so we have to ask why do most if not all of the climate models rely on it to get doomsday predictions? For the Earth to have survived as long as it has with a stable climate, through major events like ice-ages or volcanic eruptions, there is little doubt that a degree of negative climate feedback is essential.
Geologists will quite happily explain how major climate changes in the Earth are a result of geological changes. Remember that more carbon is trapped in limestone than in either plant life or fossil fuels (or both put together for that matter). Ice ages and volcanic eruptions are all things that will unarguably change the climate. Yet, with the notable exception of the extinction of the dinosaurs, it seems life has happily trundled along through it all. We're the living proof.
Of course, it's also interesting to see changes over shorter time periods. If you go to see the Roman ruins at Ephesus in Turkey, the guide will point out that the harbour is miles from where the nearest sea is today. Sea levels go up and down for many reasons - carbon dioxide not being one of them. Somehow, we survive.
Of course, astrophysicists and astronomers will happily tell us about global warming on other planets in the solar system, a period of extensive solar activity and the like. But they get poo-pooed just like all the other "real scientists" who have a view. Climate scientists have to disagree with real scientists or they would lose their funding.
Finally, why can't we trust human ingenuity? At the moment, I don't see that the evidence for anthropogenic climate change is strong enough to wreck our economies to try to change it. But if, over the next 10 or 20 years, the evidence really does come out in favour of these theories, then I have faith in our ability to solve the problem. Just like we have successfully dealt with smog in London, rivers flooding, or acid rain. We always have. ®
John Atkinson is an IT professional.