“CO2 is not a bad gas,” says Valentina Zharkova, a Professor at the Northumbria University in Newcastle, U.K. On the contrary, she points out, every garden centre uses it in its greenhouses to make plants lush and green. “We actually have a CO2 deficit in the world, and it’s three to four times less than the plants would like,” she notes, adding that the proportion of CO2 in the atmosphere has been at much higher levels throughout our planet’s history than it is now.
