The Montreal protocol, the treaty that protects the ozone layer, celebrates its 20th anniversary next month. Its achievements in reducing chlorofluorocarbons and other ozone-depleting chemicals give us much to cheer.
There may be even more to celebrate if leaders decide aggressively to pursue the significant greenhouse gas reductions possible by strengthening the treaty. Next month, the parties to the ozone treaty have the opportunity to reduce climate emissions by many times the reductions mandated under the Kyoto protocol on climate change. If would be the first time developing and developed countries explicitly agreed to mandatory measures for reducing greenhouse gas emissions.