Correcting my earlier post…
The Fourth Assessment Report (FAR) published last week by the IPCC (Intergovernmental Panel on Climate Change) was in fact only the preliminary summary. The full report will be published later in the year. The document we have so far is the summary and guide for policy-makers.
As the New Scientist points out, this is a rather special type of document. It is not a peer-reviewed paper. It has been subjected to political scrutiny and editing, to provide a text acceptable to all governments. Apparently the attitude of the US was remarkably different this time, reflecting a power-shift following the success of the Democrats in the mid-term elections.
Some people (not me, unfortunately) have already seen the full report. From this they conclude that much has been left out of the summary. For example, scientists are beginning to think that ice sheets could melt much more rapidly than previously thought. Research is not yet conclusive, and for this reason the theory was excluded from the study. You can argue if nothing is yet proven on this it would be scare-mongering to include it. On the other hand, if we have identified a potential problem, should we not flag it up as a potential risk?
Sea levels may rise faster than expected; there is observable evidence to show that this is the case. This is not in the summary report as it is inconsistent with the models currently used. The full report, due in July I think, will make interesting reading.
There’s no point in waiting; we must take action now. But we must act with care, and be ready to modify our actions as our knowledge grows and our understanding of the climate system develops.