Mostly because I’ve been around long enough to see a variety of models (and authoritative statements) crash and burn. Here are a bunch of examples (the aspects of the climate model which make me nervous follow the asterisks).
To begin with, I’ve been reading Nature since in 1972. You’ll have to look up “The Club of Rome which made a big stir that year with its report “The Limits to Growth”. None of their dire predictions came to pass. As I recall, Nature swallowed this stuff, Hook, Line and Sinker. Also look up Paul Ehrlich and his Population Bomb which predicted that we’d all be starving in the dark in 2000. In addition, note that in 1975 some people were seriously worried about global cooling.
Now for a few authoritative statements. Based on the similarity of our proteins, it was held that if we looked at man and chimp the way we look at other organisms, we’d be the same species. Ditto for Junk DNA, the 98% of our DNA which doesn’t code for protein, and which presumably wasn’t doing anything. Now of course we know about microRNAs (over 300 and counting) in our genome, which help control protein expression, and lately chromatin structure as well. We now know also that most, if not all, of our genome is actually transcribed into RNA. What all this RNA does, isn’t known at this time. One explanation is that it is basically chaff, like the turnings of a lathe. Since transcription is so energetically expensive, don’t you think natural selection would have found a way to get rid of it by this time? Consider how intracellular parasites (Leprosy) have jettisoned large parts of the genome compared to their extracellular cousins (Tuberculosis). The champ is Mycoplasma.
Closer to the present, consider the inadequacy of various financial models and the havoc they caused when followed mindlessly (Liquid Capital Management, Drysdale Securities, and the securitization of subprime mortgages come to mind).
Then there is the model of obesity and increased mortality, except that it isn’t happening. For details see
This brings us to climate models predicting that anthropogenic CO2 is the cause of (putative) global warming. Thanks to the hacked EMails of the East Anglia Climate Research unit, some of the gory details behind the some of the computer code (and the data) are being made public. It all should be.
What is really disturbing (to me) is the apparent fact [ Science vol. 326 pp. 28 - 29 '09 (2 Oct '09 ) ] that there has been NO change whatsoever in global temperatures for the past decade. There’s been a lot of contention about the earlier measurements of global temperature, but I think everyone will agree that the closer you get to the present, the more accurate the data.
Because of this (inconvenient fact?) the modelers reran their simulations 10 times for a total of 700 years and found 17 episodes of stagnating temperatures lasting 10 or more years. The LONGEST period found by the simulations was 15 years. The modelers would have more credibility if they had published this sort of thing 10 years earlier before the data became available (if they did, someone let me know).
The following is from http://news.bbc.co.uk/2/hi/8511670.stim — AKA a 13 February ’10 BBC interview with Professor Phil Jones (former head of the East Anglia Climate Research Unit).
B – Do you agree that from 1995 to the present there has been no statistically significant global warming ?
Yes, but only just. I also calculated the trend for the period 1995 to 2009. The trend (.12 Centigrade per decade) is positive, but not positive at the 95% significance level. (Translation — not statistically significant).
So there you have it, 700 years of simulations using the model found only one episode of stagnating temperatures of 15 years. The best data we have shows global temperature has stagnated for the past 15 years. How good do you think this model is? Will it be junked if global temperatures stagnate another year? another 5 years? Stay tuned.