lifetime of anthropogenic CO2
"So according to his measure of lifetime of a substance...'CO2 pulse... hang around for.. ohh...' a year maybe at most, probably a month."
Mean lifetime of the extra CO2 is 30k years, with 3/4 of the global warming impact happening in the first several hundred years: http://www.realclimate.org/index.php?p=134#more-134
