The journal
Peace Research has just published a special issue on climate change and conflict.
The introductory essay, by Nils Petter Gleditsch, says this:
On the whole, however, it seems fair to say that so far there is not yet much
evidence for climate change as an important driver of conflict.
Gleditsch also offers a gentle suggestion to the IPCC:
The IPCC is currently working on its Fifth Assessment Report, scheduled
for release
in 2013. For the first time, this report will have a
chapter on the consequences of climate change for human security,
including
armed conflict (IPCC, no date). We hope that the studies reported here will contribute to a balanced assessment by the IPCC, built on the best peer-reviewed
evidence.
That such a statement has to be made is a statement itself.