"The earth is performing an enormous disposal service for the human race. About half of the carbon we are dumping into the atmosphere does not stay there and is instead taken up by the oceans and land. Were this not the case, scientists say, the earth would probably be warming far more rapidly. One of the biggest questions in climate science is: How long will that disposal service last?"
"Remarkably, the earth’s ability to keep socking away carbon has for decades kept up with human activity, with the proportion that disappears from the atmosphere remaining close to 50 percent even as our emissions soared. Computer analyses of the climate have long predicted that the uptake would become less efficient sometime in this century. If that happened, the level of carbon dioxide in the air would begin rising faster, trapping more of the sun’s heat."