Identifying the lifecycle ODP and GWP effects of the refrigerants from household air-conditioners in Macau

Recent decades have witnessed increased public awareness of refrigerants, due to their significant global warming potential (GWP) and ozone depletion potential (ODP). Using the life cycle assessment (LCA) method, this study estimates and predicts the potential GWP and ODP of refrigerants over the entire life cycle of household air conditioners during 1998–2035 in Macau. The results show that the total environmental impacts of refrigerants were 2.19 ± 0.63 t CFC-11 eq. and 111.62 ± 17.44 Kt CO₂ eq. in 2018, respectively. If uncontrolled, cumulative emissions of ODP and GWP will rise to approximately 15.54 ± 2.63 t CFC-11 eq. and 1.31 ± 0.21 Mt. CO₂ eq. between 2019 and 2035. Specifically, ODP effects experienced a historical peak of 3.24 ± 0.54 t CFC-11 eq. in 2013, and GWP effects peaked at 128.05 ± 20.83 Kt CO₂ eq. in 2014. Furthermore, the GWP contribution in the use stage decreased from 88% in 2002 to 11% in 2028, while the end-of-life stage will gradually become the dominant stage of GWP effects. Under the most optimistic scenario (S4), the reduction rates of ODP and GWP will be 44% ± 12% and 38% ± 14%, respectively, compared to the business-as-usual (BAU) scenario in 2035, and will realize zero ODP emissions by 2032 (2 years earlier than the BAU). In the future, the management and disposal of large-scale electronic waste need to be further improved for the effective control of refrigerants in Macau.