But we are almost certainly going to miss our [global warming] deadline. We cannot get the 10 lost years back, and by the time a new global agreement to replace the Kyoto accord is negotiated and put into effect, there will probably not be enough time left to stop the warming short of the point where we must not go.
The first and most important impact of climate change on human civilisation will be an acute and permanent crisis of food supply. Eating regularly is a non-negotiable activity and countries that cannot feed their people are unlikely to be reasonable about it.
The military profession, especially is the long-established great powers, is deeply pessimistic about the likelihood that people and countries will behave well under stress. Professional officers are trained to think in terms of emergent threats, and this [climate change] is as big a threat as you are going to find. Never mind what the pundits are telling the public about the perils of climate change; what are the military strategists telling their governments. This will tell us a great deal about the probable shape of the future, although it may not tell any anything that we want to hear.
While the high-level climate talks pursue their stately progress towards some ill-defined destination, down in the trenches there is an undercurrent of suppressed panic in the conversations. The tipping points seem to be racing towards us a lot faster than people thought.
War is part of our history, but it is not in at all the same sense part of our prehistory. It is one of the innovations that occurred between nine and eleven thousand years ago when the first civilized societies were coming into being. What has been invented can be changed; war is not in our genes.
Now, for the moment, we are safe. The only kind of international violence that worries most people in the developed countries is terrorism: from imminent heart attack to a bad case of hangnail in fifteen years flat. We are very lucky people--but we need to use the time we have been granted wisely, because total war is only sleeping. All the major states are still organized for war, and all that is needed for the world to slide back into a nuclear confrontation is a twist of the kaleidoscope that shifts international relations into a new pattern of rival alliances.
There is a point of no return after which warming becomes unstoppable - and we are probably going to sail right through it. It is the point at which anthropogenic (human-caused) warming triggers huge releases of carbon dioxide from warming oceans, or similar releases of both carbon dioxide and methane from melting permafrost, or both. Most climate scientists think that point lies not far beyond 2.0°C (3.6°F) C hotter.
For most of history, war has been a more or less functional institution, providing benefits for those societies that were good at it, although the cost in money, in lives, and in suffering was always significant. Only in the past century have large numbers of people begun to question the basic assumption of civilized societies that war is inevitable and often useful.
Fiat justitia, ruat coelum. (Do the right thing even if the heavens fall.) It's not nearly as naïve a maxim as it seems, because in the real world it often turns out that doing what is morally the right thing is also, in practical terms, the right thing to do.