The Montreal Protocol, agreed to in 1987, forced the phase-out of ozone-depleting gases chlorofluorocarbons (CFCs) and later hydrochlorofluorocarbons (HCFCs). However now the Extraordinary Meeting of the Parties is being held to negotiate the phase out of hydrofluorocarbons (HFC) that have replaced CFCs and HCFCs. HFCs which are used in air conditioning systems are a greenhouse gas. Though they do not deplete the ozone layer they are a powerful greenhouse gas and are believed to contribute to climate change, specifically the warming of the planet.
In the 1980’s when Scientists identified and documented the growing hole in the ozone layer above Antarctica, the nations were alarmed. Then the NOAA Earth Systems Research Laboratory postulated the mechanism that created the Antarctic ozone hole. According to their work, the hole in the ozone was created by a reaction of ozone and chlorofluorocarbons free radicals on the surface of ice particles in the high altitude clouds that form over Antarctica.
The nations met and finally were able to negotiate the Montreal Protocol on Substances that Deplete the Ozone Layer to protect the stratospheric ozone layer by phasing out the manufacture and use of ozone-depleting substances. The Montreal Protocol was ratified by all nations and is always cited as the most successful multilateral environmental treaty to-date. Recent work by some of the same scientists has concluded that the ozone hole is shrinking. The goal of the upcoming meeting in Vienna is to amend the treaty to ban HFC (hydrofluorocarbons), too, though the final phase out of all HCFC’s is not completed.
According to a report from the Lawrence Berkeley National Laboratory, Hydrofluorocarbons (HFCs) are now one of the fastest growing greenhouse gases, with atmospheric concentrations growing every year. According to climate scientists, HFC used in the air conditioning and refrigeration industry have global warming potentials thousands of times greater than CO2, though their current impact is limited. Air conditioner sales in many emerging high population economies such as Brazil, India, and Indonesia are growing at 10-15% per year. Scientists now believe that it is essential to phase out HFCs and Methane (natural gas) to mitigate climate change. Phasing out HFCs and Methane offers faster climate change mitigation than control of CO2 alone.
I question whether the Montreal Protocol be used for this purpose. The Paris Climate Accord signed this past spring, lacks any clear path on how the nations will maintain global temperatures within 2 °C above pre-industrial levels. There are only “Intended Nationally Determined Contribution” to reducing greenhouse gas emissions and no mandated cuts. The CO2 emissions reduction pledges of the accord are voluntary. The White House pushed for keeping the countries’ individual climate pledges voluntary and not binding to sidestep the need for any new ratification of the agreement by the Senate. In 1992 the senate ratified the United Nations Framework Convention on Climate Change that required its parties set national strategies to reduce greenhouse-gas emissions and cooperate in future talks to prepare for the impacts of climate change. The George H.W. Bush administration said at the time that any “protocol or amendment” that set binding greenhouse-gas-reduction targets would have to go through the Senate.
The Lawrence Berkelyey National Laboratory estimates that by banning HFC there would be a cumulative savings up to 98 billion tonnes of CO2 equivalent emission by 2050. Using the Montreal Protocol to accomplish this would also sidestep the need for ratification of the agreement by the Senate.