The Montreal Protocol and Its Implications for Climate Change

This 2009 briefing by the Environmental and Energy Study Institute examines the Montreal Protocol's success in ozone recovery and its failure to address the climate impacts of ozone-depleting substances (ODSs) and their substitutes, hydrofluorocarbons (HFCs). It highlights the risk posed by existing ODS 'banks' and the rapid growth of HFC emissions, while discussing proposed legislative responses in the United States and internationally.

• The Montreal Protocol has been highly successful in its primary goal of ozone recovery, with ratification by 196 countries as of September 16, 2009. A complete global phase-out of ODS production is expected by 2040, and the Antarctic ozone layer is projected to return to pre-1980 levels between 2060 and 2075.
• While the Montreal Protocol addressed ODS production, it did not address 'banks'—ODSs contained in appliances, foams, and stockpiles. If these banks are not collected and destroyed, they pose a significant risk to the atmosphere; preventing these emissions over the next 20 years could reduce the total warming impact of global anthropogenic greenhouse gas emissions by 3 to 4 percent.
• The transition from ODSs to hydrofluorocarbons (HFCs) has led to a rapid increase in HFC atmospheric prevalence. HFCs have a global warming potential (GWP) between 100 and 12,500 times that of CO2. A 2009 study suggests that under a business-as-usual scenario, HFC emissions could account for 9 to 19 percent of projected global CO2-equivalent emissions by 2050.
• HFC emissions are projected to grow significantly, particularly in developing countries, which are expected to overtake developed countries in HFC emissions by 2020 and exceed them by 800 percent by 2050.
• The American Clean Energy and Security Act of 2009 (H.R. 2454) proposed specific mechanisms for ODS and HFCs. For ODSs, it considered offset credits for the destruction of CFCs (0.8 times the tons of CO2-eq destroyed). For HFCs, it proposed a separate cap-and-trade program to phase down consumption to 67 percent of the baseline by 2020 and 15 percent by 2032.
• Industry bodies suggest that a 'phase down' rather than a 'phase out' of HFCs is preferable to allow for the development of lower-GWP alternatives. Potential substitutes include ammonia and hydrocarbons, though the latter are flammable. There is also a concern that switching to alternatives could decrease appliance energy efficiency, thereby increasing CO2 emissions from energy use.

APA

Environmental and Energy Study Institute (2009). The Montreal Protocol and Its Implications for Climate Change. https://www.eesi.org/files/100609_montreal_brief.pdf

Chicago

Environmental and Energy Study Institute. The Montreal Protocol and Its Implications for Climate Change. 2009. https://www.eesi.org/files/100609_montreal_brief.pdf.

Wikipedia

{{cite report |author=Environmental and Energy Study Institute |title=The Montreal Protocol and Its Implications for Climate Change |date=October 2009 |url=https://www.eesi.org/files/100609_montreal_brief.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{environmentalandenergystudyinstitute2009montreal, author = {{Environmental and Energy Study Institute}}, title = {{The Montreal Protocol and Its Implications for Climate Change}}, institution = {Environmental and Energy Study Institute}, year = {2009}, month = oct, url = {https://www.eesi.org/files/100609_montreal_brief.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }