I know, it must be the weak-kneed environmentalist in me that shudders at the thought of little kids being eaten alive by bears, or any other attrocity resulting from the destruction of the eco-system.  Like, erm, the unnecessary starvation and suffering of animals.

Oh fucking wow.  I just stumbled upon the fundamental flaw in your argument, rk!  The reasoning that it's not worth our time looking for solutions for anything that doesn't directly affect us (just the polar bears, or sick people in Africa, or poor people in NOLA, or Tutsis in Rwanda or whoever else we are lucky enough not to be...) is exactly the kind of arrogant and simplistic logic that actually engenders crisis!  Because it's a small world, none of us live in a vacuum, and we can ignore the poor, the sick, the bears, but so long as we share the same planet, we are going to feel the repercussions of the suffering of others, weather it means eruptions of violence which hinder our ability to travel, trade, research, etc, being faced with waves of refugees from the Sudan, from Nola, from the Balkans, from the north pole, or losing forever plants, animals, etc. wich play vitals roles in the stability of the ecosphere and from which we still have so much to learn...  there are consequences to our actions.  Even for those of us who are among the most priveledged on this planet.  

Those who can make you believe absurdities can make you commit atrocities. -Voltaire

Methane hydrates are a wet dream. Coal can't be expanded, regardless of the IEA's and the USGS' wet dreams. The same for "unconventional" petroleum. Basically, wet dreams, all of them.

Plus there's the fact that all of these sources of energy suck. This is a fundamental unavoidable inescapable fact. And what that means is that they are incredibly expensive. And what that means is the cost advantage of nuclear over these other forms of energy is going to be fantastic.

Even existing coal production is going to fall under the purview of European regulations. Australian coal may be profitable but soon enough the EU is going to decide to leverage a green tax upon it. Already the French are mooting the idea. What's the use of having an environmental policy if the people you trade with subvert it?

> but given what we know of how slow recovery from high atmospheric concentrations of CO2, would that be enough to avert disaster?

All the worst-case scenarios are built on the assumption that we not only continue to output the same amount of CO2 in the future but that the amount we output keeps growing. But this is unrealistic. Even the "optimistic" scenarios where CO2 emissions are stabilized (kept constant) are unlikely. Realistically, CO2 emissions will crash.

Economics will solve the global warming problem exactly as the economists have predicted. Of course, economics won't solve the problem in exactly the way economists have predicted. Not by developing substitutes or spurring innovation, but by wiping out economies and killing tens or hundreds of thousands of people.

Remember all the accusations that economists are callous sons of bitches? It's true. When economists smile and tell you to not worry because everything's going to be fine, they really don't care that thousands will die. They know but they don't care. So don't worry because everything's going to be fine.

> And what if we manage to release large amounts of GHGs currently sequestered in frozen soil?

I would be shocked if this wasn't assumed in every climate scenario. It's already starting to happen.

The free variable is how much we output into the atmosphere. That's it. Everything else is dependent on that so there's no use moaning and agonizing about it.