City-level water withdrawal in China:Accounting methodology and applications

In the context of the freshwater crisis, accounting for water withdrawal could help planners better regulate water use in different sectors to combat water scarcity. However, the water withdrawal statistics in China are patchy, and the water data across all sectors at the city level appear to be relatively insufficient. Hence, we develop a general framework to, for the first time, estimate the water withdrawal of 58 economic–social–environmental sectors in cities in China. This methodology was applied because only inconsistent water statistics collected from different data sources at the city level are available. We applied it to 18 representative Chinese cities. Different from conventional perceptions that agriculture is usually the largest water user, industrial and household water withdrawal may also occupy the largest percentages in the water-use structure of some cities. The discrepancy among annual household water use per capita in the urban areas of different cities is relatively small (as is the case for rural areas), but that between urban and rural areas is large. As a result, increased attention should be paid to controlling industrial and urban household water use in particular cities. China should specifically prepare annual water accounts at the city level and establish a timetable to tackle water scarcity, which is a basic step toward efficient and sustainable water crisis mitigation

Achieving decent living standards in emerging economies challenges national mitigation goals for CO2 emissions

Emerging economies, low- and middle-income countries experiencing rapid population and GDP growth, face the challenge of improving their living standards while stabilizing CO2 emissions to meet net-zero goals. In this study, we quantify the CO2 emissions required for achieving decent living standards (DLS) in emerging economies. The results show that, compared to other regions, achieving DLS in emerging Asian and African economies will result in more additional CO2 emissions, particularly in the DLS indicators of Mobility and Electricity. Achievement of DLS in emerging economies will result in 8.6 Gt of additional CO2 emissions, which should not jeopardize global climate targets. However, a concerning trend arises as more than half of the emerging economies (62 out of 121) will face substantial challenges in aligning their expected emission growth for achieving DLS with their national emission mitigation targets

The Consumption-Based Carbon Emissions in the Jing-Jin-Ji Urban Agglomeration Over China's Economic Transition

Abstract Since the 2008 financial crisis, China has been undergoing an economic transition consisting of prioritizing green economic and sustainable development instead of rapid growth driven by large‐scale investment. However, there is still a lack of fine print on how subregional effort can contribute to national or full supply chain mitigation plans, especially downscaling to the city level. To bridge this knowledge gap, we selected Jing‐Jin‐Ji urban agglomeration, one of the economic centers but also featured by intensive emission for decades, to analyze the emission variance and driving forces from 2012 to 2015 as a case study. Based on the consumption accounting framework, the carbon emissions of Jing‐Jin‐Ji have decreased by 11.7 Mt CO2 in total over the study period, and most cities showed the similar descending trend. The driving forces show that the emission intensity and production structure have largely reduced Jing‐Jin‐Ji's total due to measurements of economic transition. For instance, Beijing has decreased by 28.7 Mt of emission reduction which led by declined emission intensity. By contrast, per capita demands and growth of its population were the primary forces to increase emissions. To conclude, although the mitigation achievement is undeniable, we should also note that the economic transition has not changed the uneven pattern of selected urban agglomeration so far

Carbon emissions of cities from a consumption perspective

Carbon emission inventories are the foundations of climate change mitigation and adaptation in cities. In this study, we estimated production-based CO2 emissions from fossil energy combustion and industrial processes for eleven cities in China in 2012 and used input-output theory to measure their consumption-based CO2 emissions. By comprehensively comparing production- and consumption-based emissions, six developed cities were consumption-based cities with import-depended trade pattern, while the other five were production-based cities which were mostly in medium size and might transform into consumption-based cities with socioeconomic development. Emissions from imports accounted for over 50% in consumption-based emissions in most cities, which shows the significance of interregional cooperation in tackling climate change. From the perspective of final use, emissions caused by fixed capital formation occupied first in most cities, which was determined by their economic development models

The evolution of carbon footprint in the yangtze river delta city cluster during economic transition 2012-2015

China has been undergoing an industrial transformation, shifting from an energy-intensive growth pattern. As the most developed region in China, the Yangtze River Delta (YRD) city cluster is leading the industrial trans- formation. However, the impact of the industrial transformation on carbon footprints in the YRD cities is unclear. By a city-level environmentally extended input-output model, we quantify the carbon footprint of 41 cities in the YRD city cluster for 2012 and 2015 and capture the socioeconomic driving forces of the change by structural decomposition analysis (SDA). The results show that the carbon footprint in 41 YRD cities increased from 1179.4 Mt (14.8% of China’s total) to 1329.6 Mt (16.6%) over the period. More than 60% of the footprint concentrated on the 10 largest cities, and the construction sector made the largest contribution, especially in service-based megacities. The change of production structure drove down carbon footprints in YRD cities, except light in- dustry cities and service-based cities. The industrial transfers from the coastal to inland regions result in carbon leakage, where one-third of the carbon footprint is embodied in the trade. We also find the economic recession during the transition period decreased carbon emissions by 154.2 Mt in the YRD city cluster, where the value- added rate in the YRD cities declined over the transition period, especially in service-based cities. The study highlights the positive effects of industrial transformation on low carbon transition, despite being highly heterogenous for cities

Large inter-city inequality in consumption-based CO₂ emissions for China's pearl river basin cities

Cities are leading carbon mitigation but are heterogeneous in their mitigation policies due to different socioeconomic backgrounds. Given that cities are increasingly inextricably linked, formulating mitigation policies of different cities cannot be easily achieved without comprehensive carbon inventories, who taking the inter-city supply chains into account. The Pearl River Basin is one of the important economic zones in China, with huge disparity in its cities, but very limited information is available on their consumption-based CO2 emissions. To fill this gap, we compiled a consumption-based inventory of 47 cities in the Basin for 2012. We found that the total consumption-based emissions of 47 cities was 933.8 Mt, accounting for 13.1% of China's emissions. There were huge differences in the consumption-based emissions, ranging from 3.6 Mt (Heyuan City) to 153.1 Mt (Shenzhen City). The consumption-based emissions were highly concentrated in the largest seven cities, which accounted for 52.8% of the total emissions of the Basin. The consumption-based emissions per capita also varied greatly, from 1.2 to 14.5 tons per capita. Large scale infrastructure was the biggest driving force for most cities, resulting in 42.1% to 75.6% of the emissions. At sector-level, construction, heavy industry and services were leading in emissions, contributing more than 80% of emissions. The major inter-city carbon transfers occurred within upstream cities in the developing regions and downstream cities in the Pearl River Delta respectively, instead of the transfers between upstream and downstream cities. The findings highlight that the regional mitigation strategies could mainly focus on cities in intra-province boundary, rather than inter-province boundary, and also the city-level mitigation strategies should pay attention to the key emission sectors and drivers in respect of the heterogeneity of cities

Japan prefectural emission accounts and socioeconomic data 2007 to 2015

In the wake of the Fukushima nuclear disaster, Japan largely moved away from nuclear power generation and turned back towards an energy sector dominated by fossil fuels. As a result, the pace towards reaching emission reduction targets has largely slowed down. This situation indicates that higher emissions will continue to be generated if there is no appropriate and efficient measurement implemented to bridge the energy demand gap. To contribute adequate mitigation policies, a detailed inventory of both CO2 emissions and socioeconomic factors, both at the national and regional level, should be issued. Thereby, this work contributes to a time-series emission with a record of 47 prefectures in Japan as well as their associated socioeconomic features. The compiled emission inventory is based on three major fossil fuels and 26 sectors with careful emission allocations for regional electricity generation. This dataset is uniformly formatted and can be expected to provide vital information to set regional reduction allowances and sectoral reduction priorities

Structural patterns of city-level CO2 emissions in Northwest China

In Northwest China, quantifying city-level CO2 emissions is fundamental to CO2 alleviation but encounters difficulties in data availability and quality. Further, structuring city-level emissions could be conductive to CO2 reduction. This study applies a practical methodology to 16 northwestern Chinese cities to grasp their historical trajectories of CO2 emissions. Then, structuring CO2 emissions is explored in terms of industrial structure, energy mix and urban-rural disparities for 8 northwestern Chinese cities. Results show that: (1) for 16 cities (2010–2015), capital and industrial cities generated most emissions. Meanwhile, CO2 emissions were mostly incompatible with CO2 intensity, but consistent with CO2 per capita; (2) for 8 cities (2006–2015), energy producing sectors, heavy manufacturing sectors, and coal remained major drivers of emissions. Then, the interconnection between industrial structure and energy mix exerted temporally varying impacts on emissions from energy producing sectors and heavy manufacturing sectors. Besides, urban gas consumption and rural coal use continued affecting most of household consumption emissions and household consumption emissions per capita. Moreover, the interplay between emissions and population was changed when emissions by energy type were decomposed among urban and rural households; and (3) uncertainty results averagely fall in the range of −39% to 6%. Finally, implications for CO2 reduction and future work are proposed

Full-scale, near real-time multi-regional input–output table for the global emerging economies (EMERGING)

Multi-regional input–output (MRIO) models are widely used to analyze the economic interdependencies between regions in the context of global trade and environmental research. MRIO tables enable us to teleconnect the sectors in different regions along the supply chain and track both direct and indirect impacts of global production. Yet emerging economies—despite reshaping international trade patterns and playing an increasingly important role in the world economy—are not adequately represented in existing MRIO databases, which lack key detail on countries and sectors. To bridge this gap, our study presents EMERGING: Up-to-date and full-scale MRIO tables covering 135 sectors in 245 economies over the period from 2015 to 2019. We describe in detail the steps in the development of the database and reconciliation and validation of bilateral trade data and national statistics. The EMERGING database is also designed to incorporate more official and publicly available data from national statistical institutes to ensure a high level of data quality, especially for these economies. We compare both national production-based and consumption-based value added generated from the EMERGING MRIO with the results from four major MRIO databases. Although global value-added accounts are similar across databases, we find significant discrepancies at the level of individual countries and sectors concerning conflicting benchmark data

Entropy-based Chinese city-level MRIO table framework

Cities are pivotal hubs of socioeconomic activities, and consumption in cities contributes to global environmental pressures. Compiling city-level multi-regional input-output (MRIO) tables is challenging due to the scarcity of city-level data. Here we propose an entropy-based framework to construct city-level MRIO tables. We demonstrate the new construction method and present an analysis of the carbon footprint of cities in China's Hebei province. A sensitivity analysis is conducted by introducing a weight reflecting the heterogeneity between city and province data, as an important source of uncertainty is the degree to which cities and provinces have an identical ratio of intermediate demand to total demand. We compare consumption-based emissions generated from the new MRIO to results of the MRIO based on individual city input-output tables. The findings reveal a large discrepancy in consumption-based emissions between the two MRIO tables but this is due to conflicting benchmark data used in the two tables