The ozone hole was a story many years ago, but now it is paid attention to again, and it is also a hot spot of carbon emissions. Are there many questions to answer?

Yes, and earlier. The Vienna Convention for the protection of the ozone layer, concluded in 1985, aims to reduce the impact of human activities on the ozone layer and plays a key role in eliminating the ozone hole. In 1987, the Montreal Protocol on substances that Deplete the ozone layer required the control of nearly 100 ozone depleting substances (ODS), striving to control the global total production and consumption. Subsequently, from 1990 to 1999, the London amendment, the Copenhagen Amendment, the Montreal amendment and the Beijing amendment were adopted, gradually increasing the scope of ODS control.

How does the protection of the ozone layer work together with the control of carbon emissions?

The Kigali amendment was adopted in Kigali, Rwanda, on October 15, 2016, bringing hydrofluorocarbons (HFCS) into the control scope of the Montreal Protocol on substances that Deplete the ozone layer. HFC is a common substitute for ODS, which will not damage the ozone layer, but HFC is a greenhouse gas with high global warming potential (GWP). After the adoption of the Kigali amendment, the Montreal Protocol opened a new chapter in the history of coordinated response to ozone layer depletion and climate change. The amendment has entered into force for China on September 15, 2021.

What is HFC?

The full name of HFC is hydrofluorocarbon, which does not refer to a specific chemical, but a class of substances. It does not contain chlorine or bromine that will lead to ozone depletion. Therefore, HFC is a common substitute for traditional ODS and is widely used in refrigeration, air conditioning and fire fighting industries. It is also used as foaming agent, spray can propellant and raw material for the production of other chemicals.

What controlled substances are added to the Kigali amendment?

The amendment regulates 18 HFCS, including HFC-32, hfc-125, HFC-134a, hfc-143a, HFC-152a, HFC-227ea, HFC-245fa and HFC-23, and lists the GWP of each substance (indicating that the global warming effect of this substance is equivalent to multiple of the same amount of CO2).

Since HFC has practical uses and can not be banned across the board, what is the reduction schedule?

China should freeze its production and use at the baseline level from 2024 (the baseline is the average HFC value from 2020 to 2022 plus 65% of the baseline HCFC level, calculated in carbon dioxide equivalent). From 2029, HFC production and use should not exceed 90% of the baseline, 70% of the baseline from 2035, 50% of the baseline from 2040, and 20% of the baseline from 2045.