Giz said:
Obviously it does contribute, I think the big question is whether human emissions (hur, hur) are material, i.e. does the Sun effectively drown out all the other inputs?
I was under the impression that things had been gradually getting warmer anyway over the last 3-400 years due to Solar fluctuations - though there was the global cooling scare in the 70's.
In a comparitive analysis of several possible culprits for global warming, including solar variability, David Thompson found the strongest correllation between CO2 emissions and the warming patterns of the last 150 years. Our emissions are drowning out the other effects, not the other way around. Cite:
Thompson, D. J., 1995. The seasons, global temperature, and precession, Science, 268, 59-68.
Who knows how many billions of tons of CO2 the atmosphere can absorb? Thats the $18,000,000,000,000,000 question.
The whole problem is the atmosphere "absorbing" CO2. Getting it out is the harder part, a molecule of CO2 will stay in the atmosphere an estimtated 200 years.