The problem with climate science is that the people who understand the climate know very little about economics or social policy, and the people who know about economics or social policy know little about climate.
I've said this before. The question of what, if anything, we do about CO2 relies on multiple chained statements of logic.
- CO2 is a greenhouse gas, and more CO2 in the atmosphere will raise the Earth's temperature.
- The Earth's temperature has been rising for the last 170 years, and has shown a marked rise since heavy industrialization started in the mid-20th century.
- Human burning of CO2 is causing more of it to be in the atmosphere.
- Ergo, human activity is causing the Earth to get warmer.
- Rising temperatures are bad.
- The Earth's climate will not modulate temperatures on its own--i.e. any natural negative feedback reactions (cloud cover, more precipitation, etc) to the rising temperature that offsets the CO2 greenhouse effect are not powerful enough to contain the temperature rise. This is saying that low "climate sensitivity" factors are wrong.
- On the contrary, there might be positive feedback loops (permafrost melting/rotting and releasing more CO2, increased particulate matter on glaciers and the ice caps causing them to absorb more thermal energy rather than reflect it, etc) that will either magnify the known greenhouse gas effect of CO2, or possibly destabilize our climate entirely. This is saying that high "climate sensitivity" factors are right.
- The economic effects of warming are bad.
- The economic effects of warming are WORSE than the economic effects of dismantling our carbon-based energy economy too quickly. I.e. it's saying that we can't use the economic growth of the next half-century or so to simply "live with" the warming because we'll have enough wealth in society at that point to deal with the harmful economic effects.
At this time, #1 through #4 are basically settled science. Most of those who are serious climate skeptics (i.e. actual people in the debate, not us) agree with that. At this time, #5 through #9 are not established, but all of those who are serious climate alarmists assume that they are--or at the very least we should stop emitting carbon due to the precautionary principle.
Where the actual SCIENTIFIC debate is happening is on points #5 and #6 -- what is the level of climate sensitivity? Will there be natural cooling effects that offset the CO2 warming? Or will there be positive feedback loops that exaggerate the warming and make it even worse than the CO2 itself would have done?
That's the important work, because it gives us a better idea of how much warming there will be.
BUT, it still doesn't answer the question of "what should we do about it", because absent a dire cataclysmic outcome (i.e. Earth's climate destabilizing such that agriculture can't support more than say, 500M humans), the question of what we do about is economic, not scientific.