"Who would have thought that the climate models used as the basis of IPCC greenhouse forecasts would violate 72 of 89 principles of forecasting. That's the claim from forecastingprinciples.com a site run by J. Scott Armstrong,
Professor of Marketing at the Wharton Business School, University of Pennsylvania. He and Kesten C Green from Monash University have published an audit of the forecasts from the IPCC Fourth Assessment Report. The auditors come to the view that while the scientists might know something about physics, they understand little about the science of forecasting...
Read the complete blog post by Graham Young here @ http://ambit-gambit.nationalforum.com.au/archives/002137.html
Read the paper 'Global Warming Audit, Public Policy Forecasting' by Scott Armstrong and Kesten Green presented at the International Symposium on Forecasting, 27 June 2004, Times Square, New York here @ http://www.forecastingprinciples.com/Public_Policy/global_warming_audit.html
Jen , back to the top where it began where you pondered 'Who would have thought that the climate models used as the basis of IPCC greenhouse forecasts would violate 72 of 89 principles of forecasting?. But, is there any evidence that close adherence to the 89 principles leads to better forecasts or even better decisions.?
ummm - no have a go evaluating both sides of the risk ledger.
If you read the Fourth Assessment report from the IPCC it is abundantly clear that significant doubts still surround the quality of models.
http://ipcc-wg1.ucar.edu/wg1/Comments/wg1-commentFrameset.html
These doubts include;
• the role of clouds and cloud-radiation interactions and feedback
• the extreme complexity of the climate system and its multiple interactions create limitations on the accuracy of predictions.
• Climate change has inherently chaotic aspects which can create sudden changes to climate.
• Cloud feedbacks are the largest source of uncertainty and whilst improvements have been made the uncertainty has not yet been reduced.
• The cryosphere is considered to be of particular importance and yet the IPCC admits that many physical processes are still not well understood.
So in a nutshell, the models could be ok....but also they could not be.......... Now lets cut co2 output by 90% shall we .....no one will be hurt...honest
Graham said “I've always maintained that the best model is planet earth. We know that CO2 has been at these levels, and greater, before”
Graham: By the same means we can see that the sea level was also higher in recent times. Returning to that old level would wipe out a lot of our more valuable realestate and a few good crops. In fact much of what we do in future depends on a lot of human activity remaining below that margin given out current coastline and delta development.
Transport too is structured behind some fragile dunes. It could get quite tricky launching a 787 in a number of places. But it’s that hockey stick that’s going to haunt us in the long run.
True: Rate of change determined initially from climate models will simply help with some of our engineering.
Graham - it's a bit more than that. The temperature itself is not the issue. It's the tails of the distributions - hot and cold, effects on complex ecosystems, peak events like storms and floods, and events like drought. The mean temperature is the least of your worries.
We live in a world of 6 billion humans, 30 days food supply, and we are already maladapted to climate variation.
Things like mid-latitude drying come out of the modelling. Not everything is intuitive. And actually models not behaving as per observations is very useful. Indicates a lack of understanding. Climate models are validated against 100s of processes not just temperature curves.
Luke, I've always maintained that the best model is planet earth. We know that CO2 has been at these levels, and greater, before, and we know that the place didn't turn into a cinder. So the best evidence that we have is that while the planet may be getting hotter because of greenhouse gases, this is not a human life-threatening situation.
So any model that suggests it is, probably has the wrong parameters in it. That's the sort of check that prudence would suggest that you should apply to a model, but it's not one that the IPCC process applies.
The modelling at the moment is largely of academic interest. Interesting, but not relevant. We'd be in the same position of predictive knowledge using the back of an envelope, which is what the study suggests.
Sounds of crickets doing whatever they do.
I also note that CSIRO have gotten into the ring with a newspaper rebuttal to Prof Carter in the Courier Mail. (the Courier being Queensland's most read daily newspaper).
http://www.news.com.au/couriermail/story/0,23739,22017075-27197,00.html
in response to
http://www.news.com.au/couriermail/story/0,23739,21977114-27197,00.html
Perhaps more to come?
Those that have access to Science mag can read this:
http://www.sciencemag.org/cgi/reprint/317/5834/28a.pdf
CLIMATE CHANGE: Another Global Warming Icon Comes Under Attack
Richard A. Kerr
Science 6 July 2007: 28-29.
Twentieth-century simulations would seem like a straightforward test of climate models. In the run-up to the IPCC climate science report released last February (Science, 9 February, p. 754), 14 groups ran their models under 20th-century conditions of rising greenhouse gases. As a group, the models did rather well (see figure). A narrow range of simulated warmings (purple band) falls right on the actual warming (black line) and distinctly above simulations run under conditions free of human influence (blue band).
But the group of three atmospheric scientists--Charlson; Stephen Schwartz of the Brookhaven National Laboratory in Upton, New York; and Henning Rodhe of Stockholm University, Sweden--says the close match between models and the actual warming is deceptive. The match "conveys a lot more confidence [in the models] than can be supported in actuality," says Schwartz.
Mortal Blow? How can someone even begin to compare human behaviour, which can change at a whim, to processes involving inanimate objects that must obey physical laws? The guy is a goose, he should start with valid criticisms, and acknowedge for a start the qualifications made by the scientists involved of what they believe the shortcomings of their models are, and why they have made the compromises they have.
As I said already, CO2 can't just decide to not be a greenhouse gas anymore.