jennifer

Belief in the truth of a theory is inversely proportional to the precision of the science.  At least that is what someone called Harris once said.

Modern climate science theory seems to be a case in point with imprecise extrapolation from often poorly understood variables to what have become generally accepted General Circulation Models which many scientists claim can predict future climate.  

But do the leading climate scientists, in particular the United Nation’s IPCC scientists, really believe in this theory? 

Not really. 

As their last big report was being assembled, The Fourth Assessment Report published in 2007, lead authors who asked what they really thought by way of a questionnaire. 

Climate scientist Ann Henderson-Sellers then pulled together these responses for a workshop held in Sydney in October 2007.   

Following are some of the responses from the climate scientists which fall into the category of ‘Serious inadequacies in climate change prediction that are of real concern’:

“The rush to emphasize regional climate does not have a scientifically sound basis.

“Prioritize the models so that weaker ones do not confuse/dilute the signals.

“Until and unless major oscillations in the Earth System (El Nino-Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), North Atlantic Oscillation (NAO) and Atlantic Multidecadal Oscillation (AMO) etc.) can be predicted to the extent that they are predictable, regional climate is not a well defined problem. It may never be. If that is the case then we should say so. It is not just the forecast but the confidence and uncertainty that are just as much a key.

“Climate models need to be exercised for weather prediction; there are necessary but not sufficient things that can best be tested in this framework, which is just beginning to be exploited.

“Energy budget is really worrisome; we should have had 20 years of ERBE [Earth Radiation Budget Experiment] type data by now- this would have told us about cloud feedback and climate sensitivity. I’m worried that we’ll never have a reliable long-term measurement. This combined with accurate ocean heat uptake data would really help constrain the big-picture climate change outcome, and then we can work on the details.

“[Analyse] the response of models to a single transient 20th century forcing construction. The factors leading to the spread in the responses of models over the 20th century can then be better ascertained, with forcing separated out thus from the mix of the uncertainty factors. The Fourth Assessment Report missed doing this owing essentially to the timelines that were arranged.

“Adding complexity to models, when some basic elements are not working right (e.g. the hydrological cycle) is not sound science. A hierarchy of models can help in this regard.”

So here, in the words of leading climate scientists who are part of the so-called consensus, we have recognition that there are some major problems with the climate theory on which many of the world’s governments, including the Australian government, are making major interventions into our lives and our economies.

Interestingly the issues raised by the IPCC scientists are similar to those often discussed at this blog, including the issue of cloud feedback and climate sensitivity.  There have been recent major breakthroughs in this area by Dr Roy Spencer a so-called climate change skeptic who’s research findings, if incorporated into the climate theory of the IPCC, could significantly improve it and also perhaps go some way to helping develop a more scientifically sound basis for regional climate.   

Roy Spencer’s website with links to his key published scientific papers is here:
http://www.weatherquestions.com/Roy-Spencer-on-global-warming.htm

[Thanks to Luke Walker for the link to the opinion of Ann Henderson-Sellers with the quotes from the lead authors of the IPCC Fourth Assessment Report.]

The Intergovernmental Panel on Climate Change (IPCC) has stated that: Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations, mainly carbon dioxide.  This conclusion is based on output from global climate computer models known as General Circulation Models (GCM). 

David Douglass and John Christy, in a paper recently accepted for publication and already available on the internet, have come to a different conclusion.  By considering observed, as opposed to modelled, temperature changes and at different latitude bands they conclude that:

1. El Nino and La Nina effects in the tropics have a more significant affect on global temperature anomalies than carbon dioxide, in particular it was an El Nino event that drove the 1998 global temperature maximum.

2. Variations in global temperatures since 1978 have mostly been due to climate effects in the northern hemisphere (northern extratropics) and these effects cannot be attributed to carbon dioxide.

3. Carbon dioxide has contributed a small amount to an increase in global temperatures but without what is commonly referred to as feed-back. 

David Douglas and John Christy are practicing climate scientists from the Department of Physics and Astronomy, University of Rochester, and Department of Atmospheric Science and Earth System Science Center, University of Alabama, respectively.  Their paper entitled ‘Limits on CO2 Climate Forcing from Recent Temperature Data of Earth’, was recently accepted for publication in Energy and Environment. 

A regular at this blog, Cohenite, comments on the Douglass-Christy paper in a fairly technical note already posted at the community webpage of this blog, and entitled ‘Temperature Trends and Carbon Dioxide’, suggests that there is no evidence for a contribution from carbon dioxide to global temperatures and that the role of the sun has been underestimated.