Direct Emission Intensity Research Articles

Maximizing eco-environmental gains: Exploring underground wastewater treatment plants in Beijing for sustainable urban water management

This study assessed the evolution of wastewater systems during the rapid urbanization of Beijing, with special focuses on the carbon footprints and growing underground WWTPs (u-WWTPs). Specifically, the Bishui plant (in situ constructed u-WWTP) was assessed in detail regarding eco-environmental benefits. Our results showed that, the direct emission intensity of 65 WWTPs decreased from 0.47 to 0.24 kg CO2eq/m3, when the electricity intensity increased from 0.22 to 0.39 kWh/m3 from 2010 to 2020. Bishui u-WWTP emitted 36.6 kt CO2eq/year (0.09 kg CO2eq/m3), with electricity intensity of 0.43 kg CO2eq/m3. Additionally, compare to the hypothetical relocating scenario, it saved 6.67 × 104 m2 land and 33.0 kt CO2eq/year, and the created urban river carries 6.5 × 1013 J/year heat outside town. The evaluation and balance of choice for conventional or underground WWTP should be made case by case. However, this study demonstrated that u-WWTP is not only a construction manner, but a sustainable management model with positive eco-environment effects, algin with future city expansion, and circular economy visions.

Agriculture related methane emissions embodied in China's interprovincial trade

Given that agriculture is the predominant source of anthropogenic methane, evaluating the spatio-temporal trends of agriculture related CH4 emissions embodied in trade and the related drivers is an important prerequisite for climate goals. This study first adopted the IPCC tier 2 method to account agriculture related methane emissions, by taking China as a case. The embodied CH4 emissions in the interprovincial trade were then explored by employing multiregional input-output analysis. Socioeconomic factors impacting embodied emissions were uncovered. The results show that the direct CH4 emissions from agriculture in China decreased from 15.50 Tg in 2010 to 12.49 Tg in 2020, mainly contributed by the decrease from livestock production. The direct emissions were dominated by Hunan, Sichuan and Jiangxi broken down by provinces, and rice cultivation and enteric fermentation by process. Total amount of embodied CH4 emissions increased from 11.36 Tg in 2012 to 12.10 Tg in 2015, and decreased to 11.48 Tg in 2017. Shandong had the largest embodied CH4 net inflow, while Heilongjiang had the largest embodied CH4 net outflow. The significant increases in embodied CH4 net outflow of Western China transferred from North were found. GDP per-capita and food production per unit GDP had the most positive and negative contributions to the embodied emissions, respectively. Reliability of the results was further demonstrated by using sensitivity analysis and comparing with similar studies. Finally, implications were raised, including reducing the direct emission intensities, bringing embodied CH4 emission into decision making and setting the interprovincial cooperation mechanisms.

Co-control of the haze pollution emissions in China: Insight from supply chains.

Because of rapid economic development and the increase in social demand, China has been suffering from serious air pollution, in particular, haze pollution. To mitigate haze from the source, it is essential to achieve co-control of three important haze precursors: volatile organic compounds (VOCs), sulfur dioxide (SO2 ), and nitrogen oxide (NOx ). In this study, we used the environmentally extended input-output model, structural path analysis, and structural path decomposition method to investigate changes in consumption-based emissions of three major haze precursors (i.e., NOx , SO2 , and VOCs) in China during 2007-2017. First, the results revealed that fixed capital formation was the most critical final demand to co-control the three precursors. Investment in construction was the most important behavior for co-control. Second, the most crucial common path driving the changes in emissions of the three precursors was "transportation and warehousing→household consumption" during 2007-2012, and "electricity, gas, and water supply→household consumption" during 2012-2017. Finally, direct emission intensity of transportation and warehousing, and electricity, gas, and water supplies were critical to co-control precursors. The results of this study provided a comprehensive understanding of changes in haze precursor emissions driven by demand. Therefore, China must strengthen the co-control of multiple pollutant emissions on both the production and consumption sides by adjusting supply chains. Integr Environ Assess Manag 2023;19:1048-1063. © 2022 SETAC.

Mapping urban carbon emissions in relation to local climate zones: Case of the building sector in Bangkok Metropolitan Administration, Thailand

This study focuses on carbon emissions of the building sector in relation to local climate zone (LCZ) classification, concentrating on two major parts. First, we estimated carbon emissions in the building sector, which were calculated for weekdays and weekends real-time daily energy consumption patterns. The estimations were divided into direct (from petroleum products consumption) and indirect emissions (from electricity consumption). Second, we examined urban carbon emissions mapping in relation to LCZ. Bangkok Metropolitan Administration (BMA) was used as the case study and 2016 as the base year for examination. The results illustrate that indirect emissions in Bangkok can be up to ten times higher than direct emissions. The analysis indicates that LCZ, such as compact high-rise, large low-rise, light industry, and warehouse zones had a relatively higher carbon emission intensity than others. Additionally, we identified that the compact high-rise zone has the highest indirect emission intensity, while the light industry and warehouse zone have the greatest direct emission intensity. These results provide insights into the dynamics of carbon emission characteristics in the building sector and the methodology purported here can be used to support low carbon city planning and policymaking in Bangkok.

Tracking the CO2 Emissions of China’s Coal Production via Global Supply Chains

Coal’s green mining and scientific utilization is the key to achieve the national vision of carbon peak by 2030 and carbon neutrality by 2060. Clarifying the CO2 flow of coal production is the core part of decarbonization. This study uses an environmental extended multi-regional input–output (EEMRIO) model to analyze the impact of embodied emissions on the indirect CO2 emission intensity of coal production between China’s coal mining sector and 141 countries/regions. It is found that the CO2 emission intensity of China’s coal production was 34.14 gCO2/MJ in 2014, while the direct and indirect emission intensities were 16.22 gCO2/MJ and 17.92 gCO2/MJ, respectively. From 2007 to 2014, the direct emission intensity of China’s coal production increased by 23%, while the indirect emission intensity decreased by 30%. The key material and service inputs affecting indirect carbon emissions of coal production in China are electricity service, metal manufacturing, chemical products, coal mining, and transport, which accounted for 85.5% of the total indirect emission intensity of coal production in 2014. Globally, a large portion of CO2 from Chinese coal production is emitted to meet foreign direct and indirect demands for material and service inputs. Policy implications related to this outcome are further discussed in the study.

Monthly direct and indirect greenhouse gases emissions from household consumption in the major Japanese cities

Urban household consumption contributes substantially to global greenhouse gases (GHGs) emissions. Urban household emissions encompass both direct and indirect emissions, with the former associated with the direct use of fossil fuels and the latter with the emissions embodied in the consumed goods and services. However, there is a lack of consistent and comprehensive datasets outlining in great detail emissions from urban household consumption. To bridge this data gap, we construct an emission inventory of urban household emissions for 52 major cities in Japan that covers around 500 emission categories. The dataset spans from January 2011 to December 2015 and contains 12,384 data records for direct emissions and 1,543,128 records for indirect emissions. Direct emission intensity is provided in g-CO2/JPY to facilitate both future studies of household emission in Japan, as well as act as a reference for the development of detailed household emission inventories in other countries.

Meeting international standards of cleaner production in developing countries: Challenges and financial realities facing the Indonesian cement industry

A key challenge for heavy industry in emerging economies is how to meet international greenhouse gas (GHG) emission standards since they are often based on the conditions and capacities of manufacturing in advanced countries. Firms in developing nations are typically cost-driven and reliant on older, less efficient technology: very few have achieved the relevant targets. Cement making underscores the point: no study to date has specifically quantified, in technical and financial terms, the gap between existing firm performance and global GHG emission standards. We examine Indonesia's largest cement manufacturing facility to investigate what needs to be done to overcome the discrepancy. The article starts by reviewing key contextual issues such as the facility's location, scale, organisational configuration, available materials, energy use, and technological capacities. The plant's direct emission intensity is 0.69 t CO2e/t cement, higher than the global target for 2030 (0.55 t CO2e/t). Analysis reveals six potential emissions reduction activities: (1) utilizing fly ash as a clinker substitute; (2) employing limestone as a clinker substitute; (3) using biomass from rice husks as an alternative fuel; (4) adding pre-heating stages in kilns; (5) waste heat recovery for power generation; and (6) using refused-derived fuel from municipal solid waste as an alternative fuel. These measures, if adopted in full, could reduce GHGs at the facility by up to 33%, or a total of 34,145,190 t CO2e over a 10-year timeframe (2020–2030). This abatement action would leave the facility's direct emissions intensity to 0.48 t CO2e/t cement. In present values, assuming a 10% discount rate, they would result in savings of US$415 million for a US$94 million outlay. Despite the apparent technical and financial advantages, all measures together are unlikely to be adopted, since the plant studied is well advanced in its lifecycle and the parent company is experiencing financial constraints common to those in developing nations.

Do investors care about carbon risk?

We study whether carbon emissions affect the cross-section of US stock returns. We find that stocks of firms with higher total carbon dioxide emissions (and changes in emissions) earn higher returns, controlling for size, book-to-market, and other return predictors. We cannot explain this carbon premium through differences in unexpected profitability or other known risk factors. We also find that institutional investors implement exclusionary screening based on direct emission intensity (the ratio of total emissions to sales) in a few salient industries. Overall, our results are consistent with an interpretation that investors are already demanding compensation for their exposure to carbon emission risk.

Sectoral carbon linkages of Indian economy based on hypothetical extraction model

Purpose Presentation of the different industrial carbon linkages of India. The purpose of this paper is to understand the direct and indirect impact of these industrial linkages. Design/methodology/approach This study uses a hypothetical extraction method with its various extensions. Under this method, different carbon linkages of a block are removed from the economy, and the effects of carbon linkages are determined by the difference between the original and the post-removal values. Energy and non-energy carbon linkages are also estimated. Findings “Electricity, gas and water supply (EGW)” at 655.61 Mt and 648.74 Mt had the highest total and forward linkages. “manufacturing and recycling” at 231.48 Mt had the highest backward linkage. High carbon-intensive blocks of “EGW” plus “mining and quarrying” were net emitters, while others were net absorbers. “Fuel and chemicals” at 0.08 Mt had almost neutral status. Hard coal was the main source of direct and indirect emissions. Practical implications Net emitting and key net forward blocks should reduce direct emission intensities. India should use its huge geographical potential for industrial accessibility to cheaper alternative energy. This alongside with technology/process improvements catalyzed by policy tools can help in mitigation efforts. Next, key net-backward blocks such as construction through intermediate purchases significantly stimulate emissions from other blocks. Tailored mitigation policies are needed in this regard. Originality/value By developing an understanding of India’s industrial carbon links, this study can guide policymakers. In addition, the paper lays out the framework for estimating energy and non-energy-based industrial carbon links.

Do Investors Care about Carbon Risk?

We study whether carbon emissions affect the cross-section of U.S. stock returns. We find that stocks of firms with higher total CO2 emissions (and changes in emissions) earn higher returns, controlling for size, book-to-market, and other return predictors. We cannot explain this carbon premium through differences in unexpected profitability or other known risk factors. We also find that institutional investors implement exclusionary screening based on direct emission intensity (the ratio of total emissions to sales) in a few salient industries. Overall, our results are consistent with an interpretation that investors are already demanding compensation for their exposure to carbon emission risk.

Environmental Impact of Consumption by Czech Households: Hybrid Input–Output Analysis Linked to Household Consumption Data

We quantify direct and indirect emissions resulting from Czech household consumption contributing to climate change, acidification and smog formation. We develop a hybrid environmentally extended input–output model that links the single-region input–output analysis on domestic processes with a multiregional input–output analysis to derive the indirect emissions associated with imports and part of the domestic production. We apply Almon's algorithm to transform the domestic emissions from industries to product groups. The indirect and direct emission intensities of more than hundred consumption items are then linked to expenditures of almost 3000 individual households to compute the total emissions for each household.We find that emissions attributable to households are not distributed evenly — while the first expenditure decile of households is responsible for less than 4% of all emissions, the tenth decile is responsible for 20–24%. Consumption of services and goods is least emission intensive, while use of electricity, heating, and transportation remains responsible for the major part of emissions. The most important factor of emissions attributable to household consumption is total expenditures; the expenditure elasticity of emissions is about 0.8, but we identify consumption groups which emissions are less sensitive to total expenditures (electricity, heating and food) and more sensitive (transportation, goods).

A Structural Decomposition Analysis of CO<sub>2</sub> Emission in China

This article compiles the energy input-output tables for year 2002 and 2007. Based on the energy input-out tables, we compute the carbon emission volume of China and by sector. The article also analyzes the source and change of the emission volume, based on structural decomposition analysis. The article finds that there are five factors affect the carbon dioxide. Among which the change of emission intensity, domestic need are the main reason of the decrease of emission, while production technology, trading structure and scale effect increase the emission volume. We also find that although the direct emission intensity decrease during the study period, the complete emission intensity increase by an annual rate of 3.8%, which reflect the result of energy policy is not equal in different sectors. We cannot deny the technologic and economic linkages between sectors when establish an energy policy.

CARBON DIOXIDE EMISSION PATTERNS IN LINKAGE OF INDUSTRIES WITH INVOLVEMENT OF CONSUMERS' EXPENDITURE

Carbon dioxide emission patterns in 1960-90 were examined in terms of industrial linkages and repercussions with involvement of households. The objective of this study is to clarify direct and indirect carbon dioxide emission patterns with internalization of households, and to discuss about the embodied emission patterns due to export and other final demand corresponding to the phase of rapid industrialization in Japan. The results are as follows: a) increased contribution of households to the emission was recognized in 1970-90 both through induced consumption and income repercussions, b) the trend of coefficients in the extended Leontief inverse matrix weighted by direct emission intensities of carbon dioxide showed patterns that the household sector had been likely to receive repercussion of the emission with reflection of post industrialization, c) the share of households in embodied carbon dioxide due to exports, especially of automobiles and household electric appliances, has rapidly increased following the phase of economic growth.