Tracking urban carbon footprints from production and consumption perspectives

Abstract

Cities are hotspots of socio-economic activities and greenhouse gas emissions. The aim of this study was to extend the research range of the urban carbon footprint (CF) to cover emissions embodied in products traded among regions and intra-city sectors. Using Xiamen City as a study case, the total urban-related emissions were evaluated, and the carbon flows among regions and intra-city sectors were tracked. Then five urban CF accountings were evaluated, including purely geographic accounting (PGA), communitywide infrastructure footprint (CIF), and consumption-based footprint (CBF) methods, as well as the newly defined production-based footprint (PBF) and purely production footprint (PPF). Research results show that the total urban-related emissions of Xiamen City in 2010 were 55.2 Mt CO 2 e/y, of which total carbon flow among regions or intra-city sectors accounted for 53.7 Mt CO 2 e/y. Within the total carbon flow, import and export respectively accounted for 59 and 65%, highlighting the importance of emissions embodied in trade. By regional trade balance, North America and Europe were the largest net carbon exported-to regions, and Mainland China and Taiwan the largest net carbon imported-from regions. Among intra-sector carbon flows, manufacturing was the largest emission-consuming sector of the total urban carbon flow, accounting for 77.4, and 98% of carbon export was through industrial products trade. By the PBF, PPF, CIF, PGA and CBF methods, the urban CFs were respectively 53.7 Mt CO 2 e/y, 44.8 Mt CO 2 e/y, 28.4 Mt CO 2 e/y, 23.7 Mt CO 2 e/y, and 19.0 Mt CO 2 e/y, so all of the other four CFs were higher than the CBF. All of these results indicate that urban carbon mitigation must consider the supply chain management of imported goods, the production efficiency within the city, the consumption patterns of urban consumers, and the responsibility of the ultimate consumers outside the city.

City Carbon Footprint Networks

“…We define the city CF as a consumption-based measure that adds EEI to industry-related territorial emissions (also called scope 1 emissions, see C40, ICLEI and WRI [22]) and subtracts EEE [17]. Those scope 1 emissions that do not become embodied in exports are referred to as remaining territorial emissions (RTE).…”

“…The RoW region could also be further subdivided into different countries to reveal bilateral emissions flows between Australian cities and other countries [17].…”

A novel analysis of consumption-based carbon footprints in China: Unpacking the effects of urban settlement and rural-to-urban migration

“…Thus, carbon footprints provide a broader accounting of environmental impacts. Different types of footprints have been defined based upon the different units of society being analyzed (Chavez and Ramaswami, 2013;Lin et al, 2015). For example, carbon footprints that assess the transboundary impact of production within a boundary are termed production-based footprints (PBF); those that track the transboundary impact of community-wide infrastructure-use by homes, businesses and industries within a boundary are called community-wide infrastructure footprints (CIF); while consumption-based footprints (CBF) address the impact of final consumption in a community, which is dominated by the consumption of households.…”

Multi-Scale Governance of Sustainable Natural Resource Use—Challenges and Opportunities for Monitoring and Institutional Development at the National and Global Level

“…For instance, urban infrastructure supply chain footprints have been developed to describe direct-plus-indirect energy use, GHG emissions and water use of cities [56][57][58][59], as well as of production and consumption at the city scale [60]. In addition, sector-specific benchmarks of resource use are useful in comparing infrastructure performance by sectors, e.g., provision of water, energy-efficient housing, transportation, etc.…”