EXPLAINER: The real math behind “net zero” carbon emissions

In the fight against climate change, the hot phrase now is “net zero” in carbon pollution, but what does it mean? More than 100 countries, including China and the United States, have promised that. Sometimes countries and businesses will use the phrase carbon neutrality. And there are disputes over whether net zero and carbon neutrality mean the same thing. It doesn’t quite mean no smokestacks belching carbon pollution. But it involves subtracting carbon pollution from the air,