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 Slowdown in China's Carbon Emissions Growth in the New Phase of Economic Development

China's CO2 emissions have plateaued under its commitment to reaching peak carbon emissions before 2030 in order to mitigate global climate change. This commitment is aligned with China's turn toward more sustainable development, named “the new normal” phase. This study aims to explore the role of possible socioeconomic drivers of China's CO2 emission changes by using structural decomposition analysis (SDA) for 2002–2017. The results show deceleration of China's annual emissions growth from 10% (2002–2012) to 0.3% (2012–2017), which is mainly caused by gains in energy efficiency, deceleration of economic growth, and changes in consumption patterns. Gains in energy efficiency are the most important determinants, offsetting the increase by 49% during 2012–2017. The recent moderation of emission growth is also attributed to China's decelerating annual growth rate of gross domestic product (GDP) per capita from 12% (2002–2012) to 6% (2012–2017) and to the economic transformation to consumption-led patterns in the new normal phase

All resonator based LTCC diplexer using substrate integrated waveguides

A compact diplexer is implemented in Low-Temperature-Cofired-Ceramic (LTCC) technology and consists of six coupled Substrate-Integrated-Waveguide (SIW) cavity resonators stacked in two layers. No transmission-line based junction is used. The couplings between the cavities are achieved through both SIW irises and slots placed in metal layers. The diplexer has two third-order filtering channels, centred at 2.7 and 3.3 GHz with 120 MHz bandwidths. The overall size of the diplexer is 27.74 mm (2.3 λg at 3 GHz) × 10.4 mm (0.86 λg at 3 GHz) × 0.84 mm, achieved by using an LTCC material of a high dielectric constant of 68. Simulations and measurements are in good agreement to demonstrate a compact diplexer based on an all resonator structure using high dielectric constant LTCC material

Regional development and carbon emissions in China

China announced at the Paris Climate Change Conference in 2015 that the country would reach peak carbon emissions around 2030. Since then, widespread attention has been devoted to determining when and how this goal will be achieved. This study aims to explore the role of China’s changing regional development patterns in the achievement of this goal. This study uses the logarithmic mean Divisia index (LMDI) to estimate seven socioeconomic drivers of the changes in CO2 emissions in China since 2000. The results show that China’s carbon emissions have plateaued since 2012 mainly because of energy efficiency gains and structural upgrading (i.e., industrial structure, energy mix and regional structure). Regional structure, measured by provincial economic growth shares, has drastically reduced CO2 emissions since 2012. The effects of these drivers on emissions changes varied across regions due to their different regional development patterns. Industrial structure and energy mix resulted in emissions growth in some regions, but these two drivers led to emissions reduction at the national level. For example, industrial structure reduced China’s CO2 emissions by 1.0% from 2013-2016; however, it increased CO2 emissions in the Northeast and Northwest regions by 1.7% and 0.9%, respectively. By studying China’s plateauing CO2 emissions in the new normal stage at the regional level, it is recommended that regions cooperate to improve development patterns

Demand-driven air pollutant emissions for a fast-developing region in China

Guangdong is one of many fast-developing regions in China that are confronting the challenges of air pollution mitigation and sustainable economic development. Previous studies have focused on the characterization of production-based emissions to formulate control strategies, but the drivers of emission growth and pattern changes from the consumption side have rarely been explored. In this study, we used environmentally extended input-output analysis with well-established production-based emission inventories to develop a consumption-based emission inventory for seven pollutants in the years 2007 and 2012. The results showed that the demands of construction, transport and other services dominated the emissions from the consumption perspective, followed by electric power and some machinery and light industries. The varying trends of air pollutants from 2007 to 2012 were associated with production-based control measures and changes in economic structure and trading patterns. From the consumption perspective, due to the stringent control of SO2 in power plants and key industries, the SO2 emissions underwent substantial declines, while the less controlled PM10, PM2.5, VOC and CO emissions continued to grow. The contributions of the cleaner (that is, with lower emission intensity) service sectors (third-sector industries, excluding transport, storage and post) to all seven pollutants increased. This increase could be a consequence of the expansion of the service sector in Guangdong; in this five-year period, the service sector grew by 41% in terms of its contributions to Guangdong's gross domestic product. Meanwhile, exports accounted for more than half of the emissions, but their share had started to decrease for most pollutants except VOC and CO. The results suggest that Guangdong moved towards a cleaner production and consumption pathway. The transformation of the industrial structure and increase in of urban demand should help to further reduce emissions while maintaining economic development

Energy consumption and CO2 emissions in Tibet and its cities in 2014

Because of its low level of energy consumption and the small scale of its industrial development, the Tibet Autonomous Region has historically been excluded from China's reported energy statistics, including those regarding CO2 emissions. In this paper, we estimate Tibet's energy consumption using limited online documents, and we calculate the 2014 energy-related and process-related CO2 emissions of Tibet and its seven prefecture-level administrative divisions for the first time. Our results show that 5.52 million tons of CO2 were emitted in Tibet in 2014; 33% of these emissions are associated with cement production. Tibet's emissions per capita amounted to 1.74 tons in 2014, which is substantially lower than the national average, although Tibet's emission intensity is relatively high at 0.60 tons per thousand yuan in 2014. Among Tibet's seven prefecture-level administrative divisions, Lhasa City and Shannan Region are the two largest CO2 contributors and have the highest per capita emissions and emission intensities. The Nagqu and Nyingchi regions emit little CO2 due to their farming/pasturing-dominated economies. This quantitative measure of Tibet's regional CO2 emissions provides solid data support for Tibet's actions on climate change and emission reductions

Ka-Band LTCC Stacked Substrate Integrated Waveguide Bandpass Filter

A Ka-band substrate integrated waveguide bandpass filter has been designed and fabricated using low temperature co-fired ceramic (LTCC) technology. The in-house developed SICCAS-K5F3 material with a permittivity of 6.2 and a loss tangent of 0.002 was used. The size and surface area of the proposed bandpass filter are reduced by exploiting vertical coupling in vertically laminated three-dimensional structures. The coupling between adjacent cavities is realized by a narrow slot. A vertical transition structure between the coplanar-waveguide feed line and the substrate integrated waveguide is adopted to facilitate the internal signal connection. The demonstrated third-order filter has a compact size of 6.79 mm×4.13 mm×1.34 mm (0.63λ0  × 0.38λ0  × 0.12λ0) and exhibits good performance with a low insertion loss of 1.74 dB at 27.73 GHz and a 3 dB fractional bandwidth of 10 %

A multi-regional input-output table mapping China's economic outputs and interdependencies in 2012.

Multi-regional input-output (MRIO) models are one of the most widely used approaches to analyse the economic interdependence between different regions. We utilised the latest socioeconomic datasets to compile a Chinese MRIO table for 2012 based on the modified gravity model. The MRIO table provides inter-regional and inter-sectoral economic flows among 30 economic sectors in China's 30 regions for 2012. This is the first MRIO table to reflect China's economic development pattern after the 2008 global financial crisis. The Chinese MRIO table can be used to analyse the production and consumption structure of provincial economies and the inter-regional trade pattern within China, as well as function as a tool for both national and regional economic planning. The Chinese MRIO table also provides a foundation for extensive research on environmental impacts by linking industrial and regional output to energy use, carbon emissions, environmental pollutants, and satellite accounts

Role of export industries on ozone pollution and its precursors in China

This study seeks to estimate how global supply chain relocates emissions of tropospheric ozone precursors and its impacts in shaping ozone formation. Here we show that goods produced in China for foreign markets lead to an increase of domestic non-methane volatile organic compounds (NMVOCs) emissions by 3.5 million tons in 2013; about 13% of the national total or, equivalent to half of emissions from European Union. Production for export increases concentration of NMVOCs (including some carcinogenic species) and peak ozone levels by 20–30% and 6–15% respectively, in the coastal areas. It contributes to an estimated 16,889 (3,839–30,663, 95% CI) premature deaths annually combining the effects of NMVOCs and ozone, but could be reduced by nearly 40% by closing the technology gap between China and EU. Export demand also alters the emission ratios between NMVOCs and nitrogen oxides and hence the ozone chemistry in the east and south coast

Linking city-level input-output table to urban energy footprint: Construction framework and application

Multiregion input–output (MRIO) models have become increasingly important in economic and environmental analysis. However, the current resolution of most MRIO models fails to capture the heterogeneity between subregions, especially in cities. The lack of city‐level MRIO tables has impeded the accomplishment of city‐level studies and hampered the understanding of the relationship between urban growth and consumption, and teleconnections to other regions. In this paper, we propose a partial survey‐based multiple‐layer framework for MRIO table compilation of a Chinese province that distinguishes city‐based regions. This framework can effectively address a large number of data processes and retain consistency between layers. Using the framework, we first compile a nested Hebei‐China city‐level MRIO table and then apply city‐level energy footprint accounting of the North China urban agglomeration. Our results present the critical role of Hebei cities in energy supply in 2012 and quantify energy use embodied in goods for the domestic trade. Tangshan, Shijiazhuang, and Handan are distinctive cities in the energy supply chain of other regions, for both less developed and developed regions. This multiple‐layer framework represents a feasible approach for developing subregional‐level MRIO models and offers the possibility to analyze global trade at the subregional level with limited data. The data and results from the analysis in this article are available for download from China Emission Accounts and Datasets