One minor point about your first comment here. There has been an assertion that over the 8000 years of the Holocene erase, approximately 40 ppm of CO2 was introduced into the atmosphere gradually - thus in the absence of human activity, the level in about year 1800 would have been 240 ppm.
Research has shown this to be false, and has also shown that during the Holocene there was considerable rapid fluctuations in CO2 level. This is not to say that we are not now contributing approximately 100 ppm, just that the climate is dynamic and the natural level of CO2 does vary, roughly say between 2xx and 3xx. There is no baseline, static level which is "right".
The second point you make can be vigorously debated on several levels as I am sure you are aware. You can't have an international agreement to control CO2 when the Asian countries producing the huge brown clouds are excluded and when those clouds are known to constitute more than 50% of the problem in those areas. That makes no sense. You are then attacking one thing, a possible non problem and ignoring a known problem.
We could wind up as successful at understanding and controlling "the CO2 problem" as we have with controlling those dangerous freons, proven scientifically to be responsible for the ozone hole.
