Global hydrofluorocarbon (HFC) cumulative emissions will bemore than 20 Gt CO2-equiv during 2020−2060 and have a non-negligible impacton global warming even in full compliance with the Kigali Amendment (KA).Fluorochemical manufacturers (including multinationals) in China haveaccounted for about 70% of global HFC production since 2015, of which about60% is emitted outside China. This study built an integrated model (i.e., DECAF)to estimate both territorial and exported emissions of China under three scenariosand assess the corresponding climate effects as well as abatement costs. Achievingnear-zero territorial emissions by 2060 could avoid 23 ± 4 Gt CO2-equiv ofcumulative territorial emissions (compared to the 2019 Baseline scenario) during2020−2060 at an average abatement cost of 9 ± 6 USD/t CO2-equiv. Under thenear-zero emission (including territorial and abroad) pathway, radiative forcingfrom HFCs will peak in 2037 (60 ± 6 mW/m2) with a 33% peak reduction and 8years in advance compared to the path regulated by the KA, and the radiative forcing by 2060 will be lower than that in 2019. Accelerated phase-out of HFC production in China could provide a possibility for rapid global HFC abatement and achieve greater climate benefits.

Implementing the Kigali Amendment to the Montreal Protocol has imposed certain restrictions on the production and consumption of hydrofluorocarbons (HFCs). Taking this opportunity to promote the alternatives of high global warming potential (GWP) HFC refrigerants in the room air conditioner (RAC) sector as well as improve the energy efficiency can bring double benefits. With the RAC sector as an example, a demand-emissions-cost model is developed to assess the potential and costs of emission reductions in different regions of China under different scenarios. The model includes three scenarios: a business as usual (BAU) scenario, a Kigali energy efficiency (KAE) scenario with simultaneous energy efficiency improvements following the Kigali amendment, and an accelerated transition energy efficiency (ATE) scenario with accelerated HFCs reduction and energy efficiency improvements. The results show that under the KAE and ATE scenario, the GHG emissions of the RAC sector will peak in 2025 at 389.8–393.9 Mt CO2-eq and 378.8–382.8 Mt CO2-eq in China. The main contribution to this result is the alternative of low GWP refrigerants. From 2021 to 2060, the cumulative direct emission reductions are about 6.4–7.4 Gt CO2-eq and 8.5–9.5 Gt CO2-eq in KAE and ATE, and the cumulative indirect emission re- ductions for both scenarios are 1.6–1.8 Gt CO2-eq. The cumulative abatement costs are $286–321 billion and $288–322 billion (prices in 2020). Under the ATE scenario, direct emissions from refrigerants in the RAC sector are near zero in 2060, and indirect emissions depend on the power system structure. The RAC sector’s average abatement cost varies significantly in diverse climatic environments. Given the variation in average abatement cost, it is critical to tailor mitigation policies to local conditions to ensure maximum benefits.