I see what you were referring to now.
The idea that manmade CO2 would leave the atmosphere in about a hundred years comes the idea that it would IF no more CO2 were to be released. The show on the Discovery Channel called "Population Zero" mentioned it, as did the IPCC report. The fact that it's still rising is due to more power plants coming online and more automobiles being put into use. An icreasing population and increasing industrial base will do that.
