Dynamic Carbon Emission Linkages Across Boundaries

Abstract

Cities are increasingly linked to domestic and foreign markets during rapid globalization of trade. While transboundary carbon footprints of cities have been recently highlighted, we still have limited understanding of how carbon emission linkages between sectors are reshaping urban carbon footprints through time. In this study, we propose an integrated input‐output approach to trace the dynamics of various types of carbon emission linkages associated with a city. This approach quantifies full linkages in the urban carbon system from both production‐ and consumption‐based perspectives. We assess the dynamic roles that economic sectors and activities play in manipulating multiscale linkages induced by local, domestic, and international inputs. Using Beijing as a case study, we find that imports from domestic and foreign markets have an increasing impact on the city's carbon footprint with more distant linkages during the period from 1990 to 2012. The manufacturing‐related carbon emission linkages have been increasingly transferred outside the urban boundary since 2005, while the linkages from the energy sector to services sectors remain important in Beijing's local economy. Applying systems thinking to input‐output linkage analysis provides important details on when and how carbon emission linkages evolved in cities, whereby sector‐oriented and activity‐oriented carbon mitigation policies can be formulated.

Physical and virtual carbon metabolism of global cities

“…Fossil fuel combustion-related virtual carbon, as part of cities' carbon metabolism via upstream activities, is also found to play a large part in TCI. Most cities in our study, outsource a considerable proportion of their carbon emissions by producing electricity upstream and importing materials, goods and services, significantly amplifying the climatic impact of the urban economy, similar to observations in prior studies 14,19,20 . Peters et al 36 reported virtual gaseous carbon contributed half of total carbon related to international trade.…”

“…3). Studies have reported that upstream emissons have a considerable influence on the urban carbon balance 14,15,20 . Our work further articulates that upstream emissions are significant even when they are accounted for in a broader context of the carbon metabolism that includes both physical and virtual carbon streams.…”

“…In this study, an integrated approach is developed to track various metabolic flows of physical carbon through cities as well as flows of fossil fuel combustion-related virtual carbon emissions attributed to urban demands. It provides a different perspective from the inventories of gaseous carbon emissions based on energy consumption and industrial processes (e.g., citywide inventories 7,8 based on IPCC guidelines 51 ) as well as the modeling of embodied emissions in trade (e.g., 15,19,20 ). Our approach not only captures the historical carbon emissions that have already been released to the atmosphere (either from within or outside urban boundaries), but also identifies future potential emissions hidden in carbon flows such as changes in stock of households and other economic sectors.…”

“…Considering both territorial and upstream (virtual) carbon, they identified three scopes of community-scale greenhouse gas (GHG) emissions: emissions within the administrative boundary of a community (Scope 1); energy-related embodied emissions outside the community boundary, such as purchase of electricity from outside of a city (Scope 2); and all other upstream emissions outside the city as a result of activities within a community's boundary (Scope 3). Several complementary (and partially overlapping) frameworks have been proposed to measure the carbon footprints of cities, such as community-wide infrastructure footprint [13][14][15] , consumptionbased footprint [16][17][18] , and wider production-based footprint 19,20 . Hybrid approaches of material flow analysis (MFA) and life-cycle analysis (LCA) have been used to account for carbon emissions associated with key urban materials or activities (e.g., 14,[21][22][23] ).…”

China's Trade‐Off Between Economic Benefits and Sulfur Dioxide Emissions in Changing Global Trade

“…It is thus considered a sound and relevant methodology for consumption-based accounting when studying trade-related impacts at global or national levels. Linked with inventories of emissions (e.g., air pollutants and CO 2 ), resources (e.g., water and land), and other environmental indicators, the environmental-extended multiregional input-output analysis can quantify different types of environmental impacts through complex cross-regional supply chains, including air pollutants (Lin et al, 2014), CO 2 emissions (Chen et al, 2019;Feng et al, 2013;Pan et al, 2017), energy use (Mi, Zheng, et al, 2018), resource consumption (Wiedmann, 2009), and environmental damage (Wang, Liu, et al, 2017). We also use the MRIO model to quantify the value added along supply chains, following previous studies (Ou et al, 2019;Wu et al, 2018;Zhang, Li, et al, 2018).…”