The Kigali Amendment: Phasing Down the Greenhouse Gases That Replaced Ozone-Killers
The 2016 Kigali Amendment to the Montreal Protocol requires an 80-85% global phase-down of HFC refrigerants — potent greenhouse gases — estimated to prevent 0.5°C of warming.
The Kigali Amendment (2016) is an addition to the Montreal Protocol requiring the global phase-down of hydrofluorocarbons (HFCs) — the potent greenhouse gases used as refrigerants after CFCs and HCFCs were phased out to protect the ozone layer. ## The Problem It Solves HFC Refrigerants: Ozone-Safe but Climate-Damaging, Now Facing Global Phase-Down solved ozone depletion (zero ODP) but have global warming potential hundreds to thousands of times greater than CO₂. Without intervention, HFC emissions were projected to add 0.3–0.5°C to global temperatures by 2100 as air conditioning expands in developing nations. ## Phase-Down Schedule The amendment targets an 80–85% reduction in HFC production and consumption, with different timelines: - **Developed nations**: Began reductions in 2019, reaching 85% by 2036 - **Developing nations (Group 1)**: Freeze in 2024, phased reductions to 80% by 2045 - **Developing nations (Group 2)**: Freeze in 2028, reductions to 85% by 2047 ## Implementation In the US, the AIM Act (2020) implements Kigali commitments domestically. The EPA allocated allowances for HFC production and consumption, with aggressive step-downs. R-410A equipment production has been curtailed. ## Impact With over 150 ratifying parties, the Kigali Amendment is estimated to prevent up to 0.5°C of warming by 2100 — making it one of the single most impactful climate agreements in history, building on the Montreal Protocol's track record as the most successful environmental treaty.