PARIS—The world is about to go on a carbon diet. It won’t be easy—or cheap.
Nearly 200 nations across the world on Saturday approved a first-of-its-kind universal agreement to wean Earth off fossil fuels and slow global warming, patting themselves on the back for showing such resolve.
On Sunday morning, like for many first day dieters, the reality sets in. The numbers—like calorie limits and hours needed in the gym—are daunting.
How daunting? Try more than 7.04 billion tons (if you really want to have your eyes bug out, that’s 15.5 trillion pounds). That’s how much carbon dioxide needs to stay in the ground instead of being spewed into the atmosphere for those reductions to happen, even if you take the easier of two goals mentioned in Saturday’s deal. To get to the harder goal, it’s even larger numbers.
In the pact, the countries pledged to limit global warming to about another degree Celsius (1.8 degrees Fahrenheit) from now—and if they can, only half that.
Another, more vague, goal is that by sometime in the second half of the century, man-made greenhouse gas emissions—which includes methane and other heat-trapping gases as well as carbon dioxide—won’t exceed the amount that nature absorbs. Earth’s carbon cycle, which is complex and ever-changing, would have to get back to balance.
In practice, that means the world has to emit close to zero greenhouse gases by 2070 to reach the easier goal, or by 2050 to reach the harder one, said John Schellnhuber, director of the Potsdam Institute for Climate Impact Research in Germany.
