Scientific update
Ecological network analysis of embodied fine particulate matter (PM2.5) in Beijing
Introduction
Human activities such as coal combustion, industrial processes, and road transportation are disturbing the natural balance of the atmosphere. Over the past decade, Beijing has been suffering from severe air pollution. The main constituent of the air pollution is particulate matter (PM), which has serious human health consequences as it can enter the lungs and the circulatory system. Much attention has been paid to the direct PM emissions; however, the hidden driving forces of the economic activities are rarely mentioned. Thus, policy attention is needed to control of indirect air pollutants (i.e., embodied emissions). In this study, indirect emission of PM2.5 from 42 sectors in Beijing is separated from the total emissions to see how much embodied PM2.5 from each sector has been overlooked.
Methods
Input-output analysis (IOA) is used to distinguish direct and indirect emissions from each sector and trace those embodied emissions back to the source sectors [1]. Ecological Network Analysis (ENA) as a systems-oriented methodology used to analyze the structure of ecosystems and identify flow of materials within the system [2][3] is adopted in this study to reveal the control relationship of each sector over the others in terms of both direct and indirect emissions and to determine which economic sectors drive the embodied PM2.5 emissions. The two approaches are therefore applied in tandem to investigate the embodied emissions that result from the current monetary flows and economic structure. The analysis is conducted using 2010 input-output data from the Beijing Statistical Yearbook and emission data from the Greenhouse Gas and Air Pollution Interactions and Synergies (GAINS) model.
Results
In 2010 production of petroleum, coking and chemicals was the main source of direct PM2.5 emission, 41.6 kt/y, followed by construction, 19.2 kt/y. The indirect PM2.5 emissions from wholesale & retail and manufacturing products were 21.1 kt/y and 17.7 kt/y, respectively. Overall, for all sectors, indirect emissions account for 30.75% of the total. The sectors with the most and least proportion of indirect emissions are textiles and wearing apparels and construction, respectively. From a systemic perspective, production of machinery and equipment is largely controlled by the other sectors, while sectors involving daily necessities are driving the PM2.5 emissions in the whole system.
Conclusions
According to the results, indirect PM2.5 represents a large proportion of total emissions. Production and supply of daily necessities are the dominant sectors of PM2.5, which reveals that individuals should take some responsibility for reducing PM2.5 emissions. Thus, personal purchasing power can be directed toward the production and supply of products with lower emissions and thereby alleviate air pollution and promote a more conservation-minded lifestyle.
References
[1] Leontief W (1970). Environmental repercussions and the economic structure: an input-output approach. The review of economics and statistics, 262-271.
[2] Fath BD, Patten BC (1999). Review of the foundations of network environ analysis. Ecosystems, 2(2): 167-179.
[3] Fath BD (2004). Distributed control in ecological networks. Ecological Modelling, 179(2): 235-245.
Supervisor
Brian Fath, Advanced Systems Analysis Program, IIASA
Note
Siyuan Yang, of Beijing Normal University, China, is a citizen of China. She was funded by the IIASA Chinese National Member Organization and worked in the Advanced Systems Analysis 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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