Remember when the biggest concern about our planet was that there was a growing hole in the ozone layer? After warnings that the atmospheric layer—which protects us from ultraviolet rays that can cause skin cancer and cataracts, along with harm to crops and marine life—was failing, the world rallied, finalizing the Montreal Protocol in 1987.
The protocol called for countries to end the production and consumption of chlorofluorocarbon, or CFCs, an ozone-depleting substance, which at the time were found in everything from refrigerators to aerosol cans.
The Montreal Protocol was the first worldwide environmental treaty, and it worked: the ozone is expected to recover to early 1970 levels between 2040 and 2070. But the global agreement had an even broader effect: it slowed the rate of global warming. It serves as a reminder that global consensus can help solve global problems