Five years after it fought hard to successfully negotiate favourable terms for itself, India on 18 August 2021 decided to ratify a key amendment to the Montreal Protocol, which turned the 1989 ozone-saving agreement into an extremely potent weapon in the fight against climate change as well. The Kigali Amendment, negotiated in the Rwandan capital in October 2016, enables the gradual phase-down of hydrofluorocarbons, or HFCs, a family of chemicals used extensively in the air-conditioning, refrigeration and furnishing foam industry. HFCs are known to be much worse than carbon dioxide in causing global warming. In fact, according to the UN Environment Programme (UNEP), the average global warming potential of 22 of the most used HFCs is about 2,500 times that of carbon dioxide. India’s decision to ratify the amendment was never in doubt and is little more than a formality at this stage. It was widely anticipated after the United States and China, the world’s top producers and consumers of HFCs, took similar decisions in the last few months. The amendment has already come into force from the start of 2019. But the decision to ratify it does create the right atmosphere ahead of the annual climate change conference in Glasgow this November. The 1989 Montreal Protocol is meant to protect the ozone layer of the upper atmosphere. It wasn’t originally an instrument to fight climate change. A set of chemicals, mainly the chlorofluorocarbons or CFCs, which were being used in the air-conditioning and refrigeration industry earlier, were found to be damaging the ozone layer of the upper atmosphere. Their extensive use had led to depletion of the ozone layer and formation of an “ozone hole” over the Antarctic region. The Montreal Protocol mandated the complete phase-out of CFCs and other ozone-depleting substances (ODS), which it has successfully managed to do in the last three decades. CFCs were gradually replaced, first by HCFCs, or hydrochlorofluorocarbons, in some cases, and eventually by HFCs which have minimal impact on the ozone layer. The transition from HCFCs to HFCs is still happening, particularly in the developing world. HFCs, though benign to the ozone layer, were powerful greenhouse gases. With global warming emerging as one of the biggest global challenges in the new millennium, the use of HFCs came under the scanner. HFCs still form a small part of the total greenhouse gas emissions, but with air-conditioning demand showing a significant increase, especially in countries like India, their use is rising at about 8% every year. If left unabated, their contribution to annual greenhouse gas emissions is expected to reach up to 19% by 2050. Because HFCs were not ozone-depleting, they were not controlled substances under the Montreal Protocol. They were part of the problematic greenhouse gases whose emissions sought to be curtailed through climate change instruments such as the Kyoto Protocol of 1997 and the 2015 Paris Agreement. But the Montreal Protocol has been a far more effective and successful agreement than the climate change instruments. It has already resulted in the phase-out of 98.6% of ozone-depleting substances. The remaining 1.4% is the HCFCs that are in the process of being transitioned. Accordingly, it was decided to use the Montreal Protocol to phase out HFCs as well, rather than leave them at the mercy of climate change agreements. For that to happen, an amendment to the Montreal Protocol was required. In 2016, countries agreed to include HFCs in the list of controlled substances under Montreal Protocol and decided on a schedule for its phase-down. Before the middle of this century, current HFC use has to be curtailed by at least 85 per cent. Countries have different timelines to do this. India has to achieve this target by 2047 while the developed countries have to do it by 2036. China and some other countries have a target of 2045. While the reductions for the rich countries have to begin immediately, India, and some other countries, have to begin cutting their HFC use only from 2031. If implemented successfully, the Kigali Amendment is expected to prevent about 0.5°C rise in global warming by the end of this century. No other single intervention to cut greenhouse gas emissions comes even close to this in terms of returns offered and the ease of implementation. It is thus considered crucial to achieving the Paris Agreement target of restricting temperature rise to within 2°C from pre-industrial times. And the Montreal Protocol has a fairly good track record on ensuring climate benefits as well. CFCs, the predecessors to HFCs, were also greenhouse gases, apart from being ozone-depleting. Their phase-out has already avoided an estimated 135 billion tonnes of carbon dioxide equivalent emissions between 1990 and 2010. This is three times the current annual greenhouse gas emissions. The UNEP estimates that, with Kigali Amendment, the avoided emissions could touch 420 billion tonnes of carbon dioxide equivalent by the end of the century. India had played a key role in negotiating the Kigali Amendment. It had fought hard to get an extended timeline for itself, and some other countries, for the reduction of HFC use. This was considered important for the domestic industry which was still in the process of transitioning from HCFCs to HFCs. The climate-friendly alternatives to HFCs are not yet widely available at low cost. The extended timeline was meant to give the industry some cushion to make the transition. Despite being one of the main architects of the Kigali Amendment, India was the last major country to announce its decision to ratify it. There wasn’t ever any doubt over its ratification, and it was more like a waiting game to see what China or the United States did. In the meanwhile, however, India had unveiled an ambitious action plan for the cooling industry which accounts for the phase-out of HFCs. The 20-year ‘India Cooling Action Plan’, or ICAP, released in 2019, describes cooling as a “developmental need” and seeks to address the rising demand in cooling, from buildings to transport to cold-chains, through sustainable actions. The plan estimates that the national cooling demand would grow eight times in the next 20 years, which would result in a corresponding five to eight-fold rise in the demand for refrigerants that involve the use of HFCs. The ICAP aims to bring down the refrigerant demand by 25 to 30 per cent in the next 20 years. As part of the ICAP, the government has also announced targeted R&D efforts aimed at developing low-cost alternatives to HFCs. Such efforts are already underway at the Hyderabad-based Indian Institute of Chemical Technology and IIT Bombay.