By one estimate, the pledges out there already would require a forest five times the size of India.
Instead, they'll put about $18 billion a year into renewable energy projects.
It needs more public investment, too.
The country is criticized for doing too little, too slowly, but efforts are already having an impact.
President Joe Biden wants advanced economies to finance infrastructure development in the developing world and, in doing so, counter China's influence.
The tax has been a contentious topic among Washington lawmakers, but the U.S. is behind industrialized nations in not having one in place.
If you can't pollute less, pay someone else to pollute less for you. Carbon offsets sound simple but are complicated in practice.
Ahead of the COP26 summit in Glasgow, the BBC’s climate editor takes stock of one of the U.K.’s most promising green energies: wind.