As in planet Earth. As in put more CO2 in the air and watch it turn green. According to a new peer-reviewed study by a team led by Xin Chen of the Nanjing University of Information Science and Technology, rising CO2 levels in the air have not only allowed the world to keep greening, the process is accelerating despite extended droughts in some areas. A warmer world with more CO2 is supposed to be a crisis, but the world’s plants apparently didn’t get the memo.