Nature: Ozone treaty could be used for greenhouse gases Montreal Protocol might find a new role in helping to reduce emissions of hydrofluorocarbons. The Montreal Protocol could offer a way of of scaling back the use of a class of potent greenhouse gasses. International negotiators might be bogged down in the ongoing United Nations climate talks, but there could yet be hope for an agreement on reducing emissions of a class of powerful greenhouse gases — using the same treaty that is responsible for…