That's the slogan for an ad campaign funded by the Competitive Enterprise Institute in the US.
As in "they call it pollution, we call it life".
"Your support will help us continue our fight against global warming alarmism, and for affordable energy and economic freedom around the world."You see, CO2 can't possibly be any sort of problem, no matter how much is pumped out into the atmosphere from the burning of fossil fuels, because "We breathe it out, plants breathe it in.".
(Cut to CEI seekrit bunker: Ha, those elitist scientists never thought we'd catch on to that obvious rebuttal of their claims, because they think people are stupid, and us industrialists would never ever think sheeple are stupid.. Trust us - we're making money off you guys!)
Apparently the CEI have never head of the concept of too much of a good thing. Neither have they ever heard of hypoxia, anoxia, hypoxaemia or hypercapnia. Or maybe they're sacks of crap who couldn't lie straight in bed.
Kevin Drum let his readers loose on coming up with a better slogan for CO2, and der Plau nailed it IMO:
CO2: We call it life.
No, really, go ahead -- put that plastic bag over your head.
Kevin gave der Plau's tagline an honorable mention but prefers Publius' take, which is more elaborate.