Campus carbon neutrality one country has not used up all of its allotted emissions, it can sell them to other countries that have gone over their limit. The Montreal Protocol on Substances that Deplete the Ozone Layer is an international agreement that seeks to phase out chemicals that damage the ozone layer. The Montreal protocol was signed in 1987, went into practice in 1989, and was further amended in London in 1990 and in Copenhagen in 1992. The protocol set a quicker timetable for industrialized nations to phase out chemicals than it did for developing nations. For example, developed countries were to phase-out
Montreal Protocol and HCFCs. Thus, in 2009, a study calculated that a fast phasedown of high-GWP HFCs could potentially prevent the equivalent of up to 8.8 Gt CO2-eq "per year" in emissions by 2050. A proposed phasedown of HFCs was hence projected to avoid up to 0.5C of warming by 2100 under the high-HFC growth scenario, and up to 0.35C under the low-HFC growth scenario. Recognizing the opportunity presented for fast and effective phasing down of HFCs through the Montreal Protocol, starting in 2009 the Federated States of Micronesia proposed an amendment to phase down high-GWP HFCs, with the U.S., Canada, and