It's difficult enough getting our climate forecasting accurate enough to justify definitive action. Forecasting mass human reaction to looming scarcities? There's plenty of scarcities out there now. How many are igniting conflict?

Cliff Figallo Climate Frog climatefrog.blogspot.com

whether or not climate change will exacerbate conflict through increased resource scarcity can't be predicted with certainty, but it seems likely.  

At the least, depletion of fresh water supplies in particular and degradation of forests and other natural resources will force people to adapt and cope with less.  Thomas Homer-Dixon has written extensively on this and puts forth some pretty interesting analysis to show a strong link between environment and conflict.

The most solid point in the article comes at the end, and lends some credibility to earlier assertions: "How governments respond to the challenge is at least as important as climate change itself, if not more so."  Jared Diamond's Collapse supports this assertion generally.  It IS important what we do, but that doesn't mean we should ignore the climate factor and try to mitigate it.

Still, you're right to point out that linking climate change to increasing conflicts lets corrupt regimes "off the hook" is a bit ridiculous - no one pushing the climate-conflict link is saying that.  Citing a decrease in number of conflicts along with warming is also fairly misleading; we haven't seen very many severe warming impacts yet, and a multitude of other forces are also at work, as was noted above.

Whether or not drought was a root cause of Darfur's conflict, no doubt it has exacerbated the situation by making agriculture inviable.  

Climate change will only worsen what is already a trend - ongoing depletion of natural resources by humanity.  Dealing with this challenge in general will be the defining struggle of this century, I believe, and climate change will make it more difficult.

While no expert on the subject, I'd recommend to all interested a book called "The Little Ice Age", which documents how the abnormally cold climates in the renaissance era up until the mid 1800s directly impacted major geopolitical trends, from the Napoloenic wars (driven by expansionist urges from Frances inability to feed itself - remember "let them eat cake") to new world explorations by folks sick of scrapping for resources in the Old World.

Even if one accepts that there are a multiplicity of causes, it doesn't seem a stretch to concede that environmental shifts create population pressures, and even if these are localized, that will impact politics.  

And if nothing else, it's just an interesting book.

David Deudney's chapter on "Security" in Andrew Dobson's "Political Theory and the Ecological Challenge" includes some interesting ideas about possible links between environmental degradation and wars.

He concludes by saying:

"Environmental degradation is not a threat to national security. Rather, environmentalism is a threat to the conceptual hegemony of state-centred national security discourses and institutions. For environmentalists to dress their programs in the blood-soaked garments of the war system betrays their core values and creates confusion about the real tasks at hand."