Kurt Lambeck, the president of the Australian Academy of Science, recently addressed the National Press Club on the topic of climate change. He was a lead author of the Intergovernmental Panel on Climate Change's 2001 report, and in the speech reflected on this report. He said that :

Where the 2001 IPCC report probably erred was (i) not to be sufficiently critical of the various model predictions, for clearly some were based on more complete science than others, and (ii) not to be sufficiently clear in separating out uncertainties in scientific knowledge and modelling from uncertainties arising from the future scenarios. By bundling all combinations of models and scenarios together the result gave an impression of far greater uncertainty than actually is the case.

I anticipate that the 2006 report will predict that global temperatures continue to rise up to the end of this century and that they will begin to plateau out at about this time only if present rates of CO2 and other emission are significantly reduced early in this century. A scenario with strong commitment to markets, an affluent world with high energy and materials demands, will only be able to keep this increase below about 2.5-3º C if it is accompanied by a technology-aggressive approach that would have to include more efficient generation, distribution and use of energy, clean coal technology and the permanent isolation of greenhouse gases, and new energy technologies including nuclear, renewable energy, fuel cells, etc.