Technological and industrial history of 20th-century Canada the Keele Valley Landfill was operated by the City of Toronto from 1983 until 2002, when it was closed because it was full. Chlorofluorocarbons (CFCs), the gas propellants used in aerosol spray cans, became a target for environmental concern in the 1970s and 1980s when research demonstrated that they had a harmful effect on the ozone layer in the atmosphere. The international Montreal Protocol of 1989 banned the use of these substances and they were subsequently replaced with volatile hydrocarbons. The problem with choice to reuse is still not available. There are many products that don't need to be recycled
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