Consider:
Comparing CO2 emissions to CO2 levels
My view is that, ultimately, all that matters, is how are going to continue to obtain the energy that we need, and what will it cost us, given what we know now.
To me it's unarguable that, as we consume the remaining fossil fuels given us, co2 concentration will continue to rise, and energy out the TOA will continue to fall. There is the possibility that something that we don't know about will rescue us from ourselves, but that seems unlikely to me. It seems more likely that it will be even worse than we predict as the co2 sequestered in the arctic tundra adds to ours, things will be worse that just AGW predictions.
As AGW proceeds, two civilization facts will be problamatic and expensive. The location of our cities as sea level rises, and the location of our food sources as rain patterns change.
Over the next 100 years or so we will run out of the current mix of fossil fuels anyway and have no real alternative to sustainable sources.
So the question is, how do we allocate resources over that time?
Some will go into saving our cities and maintaining our food supplies.
Some will go into trying to stretch our fossil fuel supplies as long as possible. For one thing to maintain production of all of the material that we only know how to make from fossil feedstocks now.
Some will go into re-energizing the world sustainably.
Huge numbers.
There is nothing but good that can come from a very aggressive start on that extremely difficult time period. Today most of the energy that we produce is wasted. Let's start there at the very least.