Scientific update
Hydrofluorocarbon emissions and mitigation strategies for China using the GAINS model
Introduction
Hydrofluorocarbons (HFCs) are potent greenhouse gases with a global warming potential (GWP) thousands of times greater than that of CO2. Given the high growth rate in China’s HFC production and consumption market, past and future HFC emissions in China are of great interest. China faces great mitigation challenges, especially under the 2015 North American proposed amendment to the Montreal Protocol to phase out HFCs. In this research, activity data and emission factors of HFC were updated and validated in the Greenhouse Gas and Air Pollution Interactions and Synergies (GAINS) model. HFC consumption and emissions from 12 sectors in China through 2050 were explored. Spatial distribution of HFC emissions across China at provincial level were obtained; these could be used to make provincial control regulations and reduction targets. The business-as-usual (BAU) scenario and maximum technically feasible reduction (MTFR) scenario to 2050 were developed for understanding the magnitude of HFC emissions across sectors and analyzing HFC mitigation potentials.
Methods
The GAINS model was used for emission estimation and scenario projection. Following the GAINS methodology for non-CO2 greenhouse gases, emissions from source s in region i and year t are calculated as the activity data Aits times an emission factor efism. If emissions are controlled through implementation of technology m, the fraction of the activity controlled is specified by Applitsm [1]. The driving factors for HFC consumption estimation in different sectors vary greatly, for example, GDP per capita in purchasing power parity or econometric parameters derived from the Policy Analysis Modeling System (PAMS) model. Control strategies were adjusted to allow the emission gap between the BAU and MTFR scenario to be explored. The CO2-equivalent values were obtained using emissions of HFCs, multiplied by their weighted GWP (100-year).
Results
The GWP-weighted HFC consumption in China will increase from 112 Mt CO2-eq in 2010 to 2,269 Mt CO2-eq in 2050 under the BAU scenario. Total HFC emissions are projected to increase from 104.8 Mt CO2-eq in 2010 to 462 Mt CO2-eq in 2050. Among the 12 sectors, the stationary air conditioning (56%) and foam (18%) sectors are the top two contributors. The main emissions areas are the eastern provinces (Shanghai, Zhejiang, Jiangsu), where the majority of manufacturers are located. Compared with the BAU scenario, HFC emissions will decrease to 0.91 Mt CO2-eq in 2050 under the MTFR scenario, showing great mitigation potential.
Conclusions
There is substantial potential for minimizing China’s HFC emissions. Hydrocarbon, ammonia, and low GWP alternatives (i.e., HFO) are feasible technologies that can be chosen as alternatives to HFC. When control strategies are drawn up, the share of sectors and regional differences should be taken into account.
Reference
[1] Höglund-Isaksson L, Winiwarter W, Purohit P (2013). Non-CO2 greenhouse gas emissions, mitigation potentials and costs in the EU-28 from 2005 to 2050. IIASA, Austria.
Supervisors
Pallav Purohit and Lena Höglund Isaksson, Mitigation of Air Pollution and Greenhouse Gases Program, IIASA
Note
Zihan Zhai, of Peking University, China, is a citizen of China. She was funded by the IIASA Chinese National Member Organization and worked in the Mitigation of Air Pollution and Greenhouse Gases Program during the YSSP.
Please note these Proceedings have received limited or no review from supervisors and IIASA program directors, and the views and results expressed therein do not necessarily represent IIASA, its National Member Organizations, or other organizations supporting the work.
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