The governments behind the landmark Kigali Amendment on climate-busting hydro-fluorocarbon refrigerants are taking aim at energy efficiency improvements that could double the benefit of the HFC phasedown from 0.5 to 1.0°C.

The amendment was adopted two years ago as an update to the Montreal Protocol, a successful, 30-year-old treaty originally designed to ban chemicals that were depleting the ozone layer.

“Improvements in the energy efficiency of refrigeration and air conditioning equipment during the transition to low-global-warming-potential alternative refrigerants can potentially double the climate benefits of the Kigali Amendment,” the countries concluded November 9, in a statement marking the end of negotiations in Quito, Ecuador.

The formal decision also calls for co-funding arrangements “to maintain or enhance energy efficiency when phasing down HFCs”, and called for financial cooperation with international financial institutions like the World Bank, reports the Washington, DC-based Institute for Governance and Sustainable Development.

“The stretch goal of this great treaty is to avoid up to 1.0ºC of warming by the end of the century from these combined strategies,” said IGSD President Durwood Zaelke. “The Montreal Protocol gives the world hope that it’s still possible to slow climate change in time to avoid the looming existential threat of uncontrollable climate impacts.”

The energy efficiency measure was driven by a voting bloc brought together by African nations and Micronesia, IGSD reports. The meeting postponed a decision to study the risk to the ozone layer in injecting sulphates and other aerosols into the atmosphere as a form of climate-cooling geoengineering, but the issue will likely be debated when the group reconvenes next year.

A quadrennial science assessment released during the meeting echoed recent news reports that point to the Montreal Protocol as a model for a successful international environmental treaty.

“There is now empirical evidence that the treaty’s efforts to cut chlorofluorocarbons (CFCs) and other ozone-depleting substances (ODS) was responsible for healing the stratospheric ozone layer, and that the Antarctic ozone hole should recover by the 2060s,” IGSD states. “The level of stratospheric ozone depleting substances in the atmosphere is continuing to decline, and total ozone levels in the Antarctic are showing signs of recovery.”

“Without the ozone treaty, you’d get sunburned in 5 minutes,” National Geographic headlined last year.