The Montreal Protocol was designed to heal the ozone layer. It may have also fended off several degrees of warming—and a collapse of forests and croplands.
The world has already banded together to enact an international treaty that prevented significant global warming this century—even though that wasn’t the driving goal.
In 1987, dozens of nations adopted the Montreal Protocol, agreeing to phase out the use of chlorofluorocarbons and other chemicals used in refrigerants, solvents, and other industrial products that were breaking down Earth’s protective ozone layer.
It was a landmark achievement, the most successful example of nations pulling together in the face of a complex, collective threat to the environment. Three decades later, the atmospheric ozone layer is slowly recovering, preventing additional levels of ultraviolet radiation that cause cancer, eye damage, and other health problems.
Corporations and nations are touting plans to suck greenhouse gases out of the air. But the crucial priority this decade is slashing emissions.