October continues to be a busy month for international environmental agreements. After the threshold for entry into force of the Paris Agreement was reached on October 5, 2016 (which will now enter into force on November 4, 2016), nearly 200 countries struck a landmark agreement on October 15, 2016 to reduce the emissions of hydrofluorocarbons (HFCs). In what is considered the most significant achievement on the climate change file since the Paris Agreement, it is anticipated that the Kigali Amendment to the Montreal Protocol on Substances that Deplete the Ozone Layer could prevent up to 0.5 degrees Celcius of global warming by the end of the century. The agreement reached in Kigali is significant because HFCs, which are widely used in refrigeration and air conditioning as substitutes for ozone-depleting substances, represent an extremely potent class of greenhouse gases, emissions from which are growing by up to 10% each year. There are several different types of HFCs, the most persistent of which can be several thousand times better at absorbing heat than carbon dioxide. According the United Nations Environment Programme, the current mix of HFCs being used has an impact that is 1,600 times stronger than carbon dioxide per tonne emitted.

Phase-out of HFCs

In recent years, the growing use of HFCs has been driven by increasing demand for cooling systems worldwide, particularly from a burgeoning middle class in developing countries with hot climates. Recognizing the higher cost of less carbon intensive alternatives to HFCs, the Kigali amendment provides exemptions for countries with high ambient temperatures to phase down HFCs at a slower pace. This means that some developing countries (including China and certain South American countries) will freeze their HFC use from 2024. Other developing nations (including India, Pakistan, Iran, Iraq and the Gulf states) will not freeze their use until 2028. Developed countries will be required to start limiting their use of HFCs by at least 10% from 2019. By the late 2040s, all countries are expected to consume no more than 15 to 20% of their respective baselines.

Countries also agreed to additional funding to phase-out HFCs, but the exact amount will be determined at the next meeting in Montreal in 2017. The cost of reducing HFCs is estimated to be in the billions of dollars globally. While less carbon intensive alternatives to HFCs are available (including natural refrigerants such as hydrocarbons, ammonia and carbon dioxide), these are generally more expensive than HFCs. As a result, grants for research and development of affordable alternatives to HFCs will be a priority. There is also the option to replace the current HFC mix with less potent HFCs that trap much less heat over their lifespan.

The Kigali Amendment came only days after an international deal was reached to curb emissions from the aviation sector.

Global Agreement on International Aviation Emissions

When the Paris Agreement was adopted in December 2015, it did not include any reference to the international aviation sector. The United Nations aviation agency, the International Civil Aviation Organization, responded to international pressure by designing a global market-based measure to control carbon emissions from international aviation as part of the sector’s contribution to global efforts to combat climate change. The ICAO’s Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) was adopted by the ICAO on October 6, 2016 in Montreal during its 39th Assembly.

CORSIA will begin with a pilot phase from 2021 through 2023, followed by a first phase from 2024 through 2026. Participation in both of these early stages will be voluntary, while the subsequent phase from 2027 to 2035 would see all countries on board, except for certain small countries and countries with very low levels of aviation activity. The program will be reviewed every three years. CORSIA is designed to complement the other mitigation measures the air transport community is already pursuing to reduce carbon emissions from international aviation, including technical and operational improvements and advances in the production and use of sustainable alternative fuels for aviation.