Pathway and Cost-Benefit Analysis to Achieve China's Zero Hydrofluorocarbon Emissions.

Global hydrofluorocarbon (HFC) cumulative emissions will be more than 20 Gt CO2-equiv during 2020-2060 and have a non-negligible impact on global warming even in full compliance with the Kigali Amendment (KA). Fluorochemical manufacturers (including multinationals) in China have accounted for about 70% of global HFC production since 2015, of which about 60% is emitted outside China. This study built an integrated model (i.e., DECAF) to estimate both territorial and exported emissions of China under three scenarios and assess the corresponding climate effects as well as abatement costs. Achieving near-zero territorial emissions by 2060 could avoid 23 ± 4 Gt CO2-equiv of cumulative territorial emissions (compared to the 2019 Baseline scenario) during 2020-2060 at an average abatement cost of 9 ± 6 USD/t CO2-equiv. Under the near-zero emission (including territorial and abroad) pathway, radiative forcing from HFCs will peak in 2037 (60 ± 6 mW/m2) with a 33% peak reduction and 8 years 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.

Realizing low-carbon development in a developing and industrializing region: Impacts of industrial structure change on CO2 emissions in southwest China.

China is undergoing rapid industrial structure change, resulting in great disparities in industrialization stages and CO2 emission patterns across regions. In this study, we focused on the southwest economic zone (including Chongqing, Sichuan, Guangxi, Yunnan, and Guizhou), which is in the middle-industrialization stage and aims to mitigate CO2 emissions during strategic industrial transformation. We applied a framework with refined indicators based on input-output analysis (IOA) and structural decomposition analysis (SDA) to characterize and quantify the impact of industrial structure change on CO2 emissions during 2002-2012. In this period, construction ranked first in CO2 emission due to relatively high-carbon production structure and increasing share in final demand, which increased construction related CO2 emissions. Furthermore, we found that diversification in development and competitive industries had different impacts on CO2 emission trends. Yunnan and Guizhou experienced a transition from light manufacturing to resource-related manufacturing; therefore, CO2 emissions in resource-related manufacturing showed an increasing trend due to the extensive production structure in the two provinces, while it showed a decreasing trend in the other three provinces. Moreover, Chongqing, Sichuan, and Guangxi showed an apparent expansion trend in machinery manufacturing and related CO2 emissions, driven by investment, final demand structure, and production structure changes. Meanwhile, this zone avoided large-scale CO2 emissions in these sectors through net imports, by making good use of geographical advantages and trade structure. The CO2 emissions of the service sectors showed increasing trends due to increasing proportions in consumption structure and final demand structure. Furthermore, this led to a transition from consumer services to producer services with expansion. Among the five provinces, Chongqing had the lowest-carbon development pattern, owing to its higher technical levels of manufacturing and relatively lower-carbon production structure, which could be a reference point for rapid low-carbon economic development under middle industrialization for the other provinces or regions with the similar industrial characteristics.

Banks, emissions, and environmental impacts of China's ozone depletion substances and hydrofluorocarbon substitutes during 1980-2020.

Ozone-depleting substances (ODSs), which also contribute to global warming, have been controlled by the Montreal Protocol (MP) since 1987. China joined the MP in 1991 and began reducing production and consumption of ODSs in the country, leading to a decrease in emissions of ODSs. Based on the Intergovernmental Panel on Climate Change guidelines, the latest emission factors and actual consumption in China (MP scenario), both the historical banks and the historical emissions of ODSs and substitute hydrofluorocarbons (HFCs) during 1980-2020 were calculated. To understand the reduction in ODS and HFC emissions by implementing the MP, we also estimated China's virtual emissions (NMP, i.e., the amount of ODS emissions without the MP) over the same period. The avoided cumulative ODS consumption and emission values of 10.8 and 5.8 (4.8-6.9) million tonnes (Mt) of CFC-11-equivalent (eq), respectively, were estimated by comparing the two scenarios. Furthermore, 26 (22-33) giga tonnes (Gt) of CO2-eq emissions, equivalent to an increase of 0.031 W m-2 radiative forcing, were estimated to be avoided by 2020, which will prevent an additional 0.025 °C increase in temperature. The MP implemented by China has resulted in substantial environmental benefits over the last 30 years. However, owing to the massive use of HFCs as substitutes, the cumulative emissions reached 2286 Mt. CO2-eq during 1990-2020, and it will be challenging to phase down HFCs in the environment after China ratified the Kigali Amendment in 2021.