CO2 Emission Mitigation Potential Research Articles

Contemporary roof pattern for energy efficient buildings: Air conditioning cost alleviation, CO2 emission mitigation potential and acceptable payback period

Buildings account for a significant portion of global energy use and consumption. Buildings have substantial energy consumption due to the use of heating, ventilation, and cooling systems. It is evident that the use of insulation materials and phase change materials (PCMs) in the design of buildings can effectively reduce the cost of air conditioning by reducing external heat gains and losses. Additionally, the use of environmentally friendly, cost-effective, and natural materials can be beneficial from an environmental standpoint. This paper aims to evaluate the potential for cost savings in the air conditioning of various PCMs and insulation-stuffed building roof configurations. In that respect, four types of phase change materials (HS29, HS36, FS42, and FS30) and four insulation materials (Therma cork, sawdust, aerogel, and sheep wool) were selected. The thermophysical properties of PCMs (solid and liquid state), insulation materials, and building elements were determined experimentally as per ASTM D 5334 standards. Ten various building roof models (contemporary roof pattern) are studied with four various PCMs and four various insulations. In addition, novel building roof design integrated with PCM/insulation were analysed numerically, related to environmental conditions that refer to two different scenarios in India (hot dry and composite climates). It further analyses the reduction in greenhouse gas emissions associated with different roof configurations. The aforementioned PCM/insulation materials were stuffed in the void spaces of the contemporary roof pattern. Thermo-economic analysis of novel roof design with PCM/insulation materials on air-conditioning costs, carbon dioxide emissions and payback time are compared with conventional roofs (CR) and contemporary roof patterns (CRP). The thermo-economic analysis was carried out based on the number of degree-hours of heating and cooling to determine the building's annual energy usage. HS29 PCM stuffed roof pattern (HS29RP) saved the highest total energy cost savings of 11.89/14.71 $/m2/year when compared with conventional roof and 11.35/13.89 $/m2/year compared with contemporary roof pattern for Jabalpur/Kota climatic conditions. HS29 PCM stuffed roof pattern (HS29RP) exhibits the maximum carbon emission mitigation of 215.32/275.37 kg/kWh when compared with conventional roof and 204.95/259.57 kg/kWh for climatic conditions of Jabalpur/Kota. While considering shortest payback span, sawdust stuffed roof pattern shows the minimum payback period of 0.69 and 2.15 years when compared with conventional roof and contemporary roof pattern. The findings of this research offer significant contributions to the development of energy-efficient building envelopes applicable to a wider range of buildings, including those with and without air conditioning systems.

CO2 emission mitigation of a hybrid photovoltaic and cogeneration system in computer hardware manufacturing industry: A case study in Thailand

Abstract In the wake of COP26 and the growing urgency of addressing climate change, achieving carbon neutrality by 2050 has become a central global objective. This imperative extends to industries like computer hardware manufacturing, which are now actively pursuing decarbonization strategies through the strategic adoption of renewable energy sources and energy efficiency enhancements. This research paper assessed the CO2 emission mitigation potential of a hybrid system of photovoltaic (PV) roof and cogeneration where a large factory of computer hardware manufacturing in tropical Thailand was selected as a study site. On one hand, a one-Megawatt photovoltaic system was installed over the roof of the production building to generate electricity from solar radiation to serve the building. On the other hand, a twenty-four-Megawatt cogeneration system of gas engines as the prime mover was used to supply power to meet the building’s electricity demand. Waste heat from the gas engine was used by the absorption chiller to generate chilled water for cooling inside the building. Based on the system equipment specifications, the annual simulation using Thailand’s solar radiation showed that the installed photovoltaic system could generate electricity of 1,412.4 MWhelec/year while the implementation of the absorption chillers for cooling helped to reduce the electrical energy consumed by the traditional electric chiller by 10,211.4 MWhelec/year. In our study case where the CO2 emission of the grid power was 0.4758 kgCO2/kWhelec in the year 2022 and was reduced to 0.350 kgCO2/kWhelec in the year 2050, the total CO2 emission mitigation from the hybrid photovoltaic and cogeneration system with the genset efficiency of 50% and the waste heat recovery of 60% could reduce approximately 207,388.5TonCO2 for over 20 years as compared to the scenario where the grid electricity alone powered the building. These findings underscored the critical role of the proposed hybrid system in addressing the climate crisis and exemplified how the industry could make meaningful strides toward more environmental sustainability.

Assessment of energy saving and CO2 emission mitigation of low-lift cooling in computer hardware manufacturing industry: A case study in Thailand

Abstract Released heat from production process contributes the largest proportion of cooling load in computer hardware manufacturing industry. According to traditional design practice, chiller plant produces chilled water at a temperature of 7°C to treat the entire load from the production process and from the comfort air-conditioning in buildings. However, the heat from the process is solely the sensible component where high-temperature chilled water (e.g., 15°C) can be used for the heat removal, the chillers equipped with low temperature-lift technology thus offer a great opportunity to improve the plant’s cooling performance. Under the critical global warming situation and the need of decarbonizing industry, this paper investigated the energy saving and CO2 emission mitigation potential of the low-lift technology by which the chiller plant of high-temperature chilled water (15°C) is dedicated for the production process cooling, and the traditional chiller plant of the low-temperature chilled water is used to serve the building air-conditioning. The study site was a large factory of computer hardware manufacturing in Thailand. Through detailed energy auditing, the cooling load profile of the production process was established, and it was used to design the low-lift chiller plant. The annual simulation results showed that in our study case the low-lift chiller plant together with variable motor speed control had 31.6% higher cooling performance than the traditional chiller plant. The plant could reduce the energy consumption by 5,550 MWhelec/year. As the CO2 emission of the grid power in Thailand was 0.47 kgCO2/kWh in 2023 and it was expected to reduce to 0.35 kgCO2/kWh in 2050, the CO2 emissions from implementing the low-lift cooling could be reduced by 49,400 TonCO2 over a course of the 20-year project lifetime. The study results encouraged the low-lift cooling technology as a practical energy efficiency measure in computer hardware manufacturing industry. To our knowledge, while past research focused on the low-lift cooling in building air-conditioning, the study was the first potential assessment project of the low-lift cooling as a deep decarbonization technology for the computer hardware manufacturing industry in Thailand.

Driving Forces and Mitigation Potential of CO2 Emissions for Ship Transportation in Guangdong Province, China

Ships are important sources of carbon dioxide (CO2) emissions in Guangdong Province. The study of historical evolutions, drivers, and projected pathways of CO2 emissions can provide scientific support for the development of carbon peaking and carbon neutral strategies in Guangdong Province. The emission factor method, log-average index (LMDI) method, and scenario analysis method were adopted to estimate CO2 emissions, identify the drivers, and explore the mitigation potential from ships in Guangdong Province, separately. The results showed that:① CO2 emissions from ships in Guangdong Province increased from 3.319 4 million tons to 6.392 9 million tons from 2006 to 2020, with dry bulk carriers and container ships being the main ship types causing the increase in emissions. ② The positive drivers of CO2 emissions from ships in Guangdong Province from 2006 to 2020 were transport intensity (51%) and economic factors (49%), and the negative drivers were energy intensity (93%) and cargo class structure (7%). ③ Carbon peaking would not be reached by 2030 if Guangdong Province maintains the current policy (baseline scenario) for ship transportation. ④ Simultaneous optimization of the energy structure and promotion of the energy intensity (energy-efficient and low-carbon scenario) had a 56.51% potential to reduce CO2 emissions from ships compared to the baseline scenario. This can provide scientific support for Guangdong Province to develop a carbon peaking and carbon neutral control strategy for the shipping industry.

Life cycle assessment shows that retrofitting coal-fired power plants with fuel cells will substantially reduce greenhouse gas emissions

Life cycle assessment shows that retrofitting coal-fired power plants with fuel cells will substantially reduce greenhouse gas emissions

Energy, environmental and economic analyses of an indirect cocoa bean solar dryer: A comparison between natural and forced convections

The objective of the research is to present, the numerical simulation modelling of cocoa bean dryer in natural, forced and combined forced and natural convection to predict their effectiveness in a tropical environment. Cost analysis and CO2 mitigation potential of the solar dryer were also presented. The finite difference and fourth-order Runge Kutta method were used to resolve the iterative equations. The drying kinetics, drying rates, CO2 emissions mitigation, thermal efficiency and payback period are estimated in Yaoundé climate in Cameroon. It was difficult to have the moisture content of the product in equilibrium with ambient air using only natural convection. The best mode of functioning is to use forced convection during sunny period and natural convection during not sunny period. With an initial moisture content of 1.2 kg/kg (db), it took 32 h of drying time to obtained final moisture content of 0.15 kg/kg (db) using forced convection during the day and natural convection during the night for each month. The gradients of humidity and temperature are sufficient to have a homogeneous drying in the established product layers. The specific energy consumption range between 5 and 15 kWh per kg of humidity extracted for the combined natural and forced convection. The thermal efficiency of the solar collector is above 30%, while the global thermal efficiency ranges from 5% to 18%. The CO2 emissions mitigation potential per mass of evaporated water ranged between 15 and 25 g of CO2 per kg of water evaporated in a day. The calculated payback period was 2.19 years.

Decoupling and mitigation potential analysis of CO2 emissions from Pakistan's transport sector

The transport sector has become one of the major economic, huge fossil fuel energy consumption, and carbon dioxide (CO2) emitting sector of Pakistan. This study applies the logarithmic mean Divisia index (LMDI) and Tapio's decoupling approach to estimate decoupling state and mitigation potential of CO2 emissions from the transport sector during 1984–2018. LMDI technique is applied to detect the influencing variables (i.e. carbon coefficient, fuel consumption, total energy consumption, and turn over economy), which oversee CO2 emissions. The outcomes show that CO2 coefficient effect is the factor which is decreasing CO2 emissions while economic growth (EG) effect is the factor which is growing CO2 emissions. The decoupling index is also applied to influencing factors which reflect the EG factors on CO2 emissions from the transport sector. The consequences confirm that during 1984–2018, the CO2 emissions show an expensive coupling with EG. Weak decoupling occurred only in the sub-periods 1999–2003, 2004–2008, and 2009–2013. Similarly, the CO2 emissions occurred from only three decoupling grades. Furthermore, a mitigation model based on the above impacting variables estimates the mitigation rate of CO2 emissions and showed that the CO2 mitigation seemed in 1999–2003, 2004–2008, and 2009–2013. Finally, forecasting outcomes of Tapio decoupling index show a weak decoupling during 2018–2030. Therefore, based on the empirical outcomes, this study puts forward a few policy suggestions to efficiently enhance the decoupling between Pakistan's transport CO2 emissions and EG.

A comparative analysis of the life cycle environmental emissions from wind and coal power: Evidence from China

Wind power is widely regarded as a clean, low-carbon, and alternative energy source for coal-fired power. However, quantitative studies of wind power are limited in indicating the differences in environmental impacts as compared with coal-fired power. Therefore, a life cycle assessment (LCA) is utilized to compare the environmental emissions from wind and coal power. Based on LCA results, material and energy flow of wind power are depicted, and its substitution effects are estimated. For 1 kilowatt-hour (kWh), wind power only consumes 4% of the total amount of carbon dioxide (CO2) emissions and environmental costs related to coal power. Furthermore, energy and emissions intensities of wind power are concentrated in the manufacturing stage, while those of coal power focus on the operation and maintenance stage. In addition, the environmental costs of the construction stage of wind power are slightly higher than that of the production and manufacturing stage due to the using of purchased electricity, accounting for 47% of the total environmental costs. Based on a consequential LCA, the mitigation potential of CO2 emissions of wind power is estimated to be less than 500 million tons during the period of China’s 12th Five-Year Plan (5 years). More than 300 million tons reduction is expected to be realized in 2020. Finally, some policy implications for Chinese policymakers are proposed to promote the development of the wind power industry.

CO2 emissions mitigation potential of buyer consolidation and rail-based intermodal transport in the China-Europe container supply chains

Abstact Freight transport is an increasingly important contributor to global warming. With the projected development of international trade, finding the most energy efficient ways of service intercontinental trades is a key challenge. China-Europe containerized trades are among the most important in this setting. The typical structure of the supply chains associated with this trade is that containers are stuffed in China and then cargos are subsequently cross-docked at major European logistics hubs or distribution centers in the destination countries for further road transport to the final retailing points. This solution may not be optimal from an environmental perspective. To pursue an increasingly sustainable supply chain solution, early movers in the market have adopted an alternative solution that is characterized by upstream buyer consolidation and downstream rail-based intermodal transport. This paper develops a set of mathematical models for analyzing the environmental saving potential of such alternative solutions, encompassing relevant energy use and energy mix data of all the legs and nodes in the supply chains. The empirical analysis is based on a case obtained from a Swedish retailer with a chain of retailing points in Scandinavia and Poland. From an activity-based approach, our findings suggest that upstream buyer consolidation may facilitate the integration of rail and road transport in the destination country, increase container utilization, replace 20-foot containers by 40-foot containers and eliminate the extra de-/re-consolidation activity in the traditional solution, thereby reducing CO2 emissions of the supply chain. This, more efficient supply chain solution, may facilitate a modal shift in the downstream part of the supply chains, which may be attractive to logistics providers, retailers and customers in search of ways of curbing CO2 emissions. The models and analytical framework developed may also be used by practitioners and researchers for analyzing other alternative supply chain designs.

Coupled LMDI and system dynamics model for estimating urban CO2 emission mitigation potential in Shanghai, China

In this study, both the extended logarithmic mean divisia index (LMDI) model and the system dynamics (SD) model were used to explore determinants of CO2 emission change during 1995–2016 and to predict the emission mitigation potential from 2016 to 2030 in Shanghai (China). Some novel factors (e.g., private car ownership, urban travel structure, and income level) were chosen and added to the LMDI model. The combination of the LMDI and SD models might provide a new pathway for policymakers to cope with such sophisticated issues. The results showed that: (1) GDP per capita is the main positive driving force for CO2 emission growth, followed by population, average income level per capita, and car ownership per capita. Energy intensity is the main factor for carbon mitigation, followed by economic structure, residential energy intensity, and emission coefficient. (2) The additive effect of different scenarios is essential for emission control. (3) CO2 emissions and emission per capita would peak by 2025 at the level of 218.20 Mt and 8.83 t per capita, respectively. Tertiary industry and public travel model promotion, power generation structure, and primary energy structure optimization would facilitate emission mitigation in Shanghai, which could also be a reference for other similar mega-cities in developing countries.

Research on the decoupling trend and mitigation potential of CO2 emissions from China's transport sector

The purpose of this paper is to study the decoupling status and mitigation potential of CO2 emissions from China's transport sector over the period 1991–2015. Firstly, this paper utilizes the Log-Mean Divisia Index (LMDI) technique to identify influencing factors, which govern CO2 emissions from China's transport sector. Over the study period, the CO2 coefficient effect (ΔCcft) was the main factor for decreasing CO2 emissions. However, the economic growth effect (ΔCgt) was the main factor for increasing CO2 emissions. Then, the decoupling indicator is also constructed based on the above influencing factors, which can be utilized to reflect the dependence degree of economic development on CO2 emissions from China's transport sector. During 1991–2015, the CO2 emissions from China's transport sector presented expansive coupling (EC) with economic development. Weak decoupling (WD) only appeared in the sub-period 1991–1995. The CO2 emissions only presented 3 decoupling grades in all sub-period and the period 1991–2015: Ⅱ, Ⅲ, and Ⅳ. Furthermore, the above influencing factors are also used to establish a theoretical mitigation model, which is used to reflect the mitigation potential of CO2 emissions from China's transport sector. Finally, the occurrence of CO2 mitigation only appeared in 3 sub-periods: 1991–1995, 2005–2010, and 2010–2015.

Large-scale implementation of electric road systems: Associated costs and the impact on CO2 emissions

This study investigates a large-scale implementation of an electric road system (ERS) in Norway and Sweden by identifying: (i) which roads; (ii) how much of the road network; and (iii) which vehicle types are beneficial to electrify based on an analysis of current road traffic volumes, CO2 emissions mitigation potential, and infrastructure investment costs. All the European (E) and National (N) roads in Norway and Sweden were included, while assuming different degrees of electrification in terms of the fraction of the road length with an ERS, prioritizing roads with high-traffic loads. The results show that implementing an ERS already for 25% of the E- and N-road lengths could result in electrification of 70% of the traffic on these roads, as well as 35% of the total vehicle kilometers in Norway and Sweden. The ERS will then connect some of the larger cities with ERS. Installation of ERS on all the E- and N-roads in the two countries would cover more than 60% of the CO2 emissions from all heavy traffic assuming all vehicles run on electricity. For roads with an average daily traffic of >6800 and >1200 vehicles per day, the costs of infrastructure investment are ∼0.03 €2016 per vkm and ∼0.15 €2016 per vkm, respectively. Thereby, for roads with high traffic volumes using an ERS, the total driving cost per km using an ERS (0.23–0.55 €2016 per vkm) does not seem to be an issue. Light vehicles appear to be important bringing down the ERS infrastructure cost.

Experimental investigation of a vertical earth-to-air heat exchanger system

A vertical earth-to-air heat exchanger system (VEAHE) system was proposed in this study. Compared to conventional EAHE systems, it has smaller land use and higher geothermal energy utilization efficiency. To validate its thermal and economic feasibility, an experimental setup was established to examine the variation of its outlet air temperature, air temperature along the tube and soil temperature. Also, the energy metrics of the proposed system were calculated for its economic assessment. Results showed that the outlet air temperature of this system ranged from 22.4 °C to 24.4 °C in summer and from 16.0 °C to 18.0 °C in winter. A detailed air temperature profile along the whole tube revealed that, the air temperature difference under 5 m in deep soil was more than twice as many as that from the inlet to 5 m. For the soil temperature at different depths, its recovery rate approximately equaled to the corresponding changing rate at the same depth during operation. For the proposed system, its energy payback time was calculated as 8.2 years, and its CO2 emission mitigation potential and total carbon credits were calculated as 7170.42 kg and $203.43 respectively, given an economic lifespan of 20 years. In addition, its monetary payback period was calculated as 17.5 years. The above results demonstrate the feasibility and effectiveness of the proposed system in exploiting deep ground soil as a natural heat sink/source in summer/winter. Meanwhile, the energy metrics analysis indicates that the proposed system is economically viable.

An overview of carbon dioxide emissions from China's ferrous metal industry: 1991-2030

The ferrous metal industry is one of the biggest source of industrial energy consumption and CO2 emissions in China. This paper first employs the LMDI model to explore what influenced CO2 emissions from China's ferrous metal industry from 1991 to 2016. The CO2 emission variation is decomposed into industry activity effect (ΔCG), energy intensity effect (ΔCEI), industry scale effect (ΔCL), energy structure effect (ΔCES), industry structure effect (ΔCIS) and emission coefficient effect (ΔCCOE). The grey prediction method and scenario analysis are then adopted to investigate the CO2 emission mitigation potential in China's ferrous metal industry during 2017–2030. The results reveal that: 1) CO2 emissions from China's ferrous metal industry grew dramatically —by 508.35%— from 213.48 Mt in 1991 to 1298.71 Mt in 2016; 2) overall, ΔCG was the leading aggravating factor and ΔCEI was key mitigating factor of emissions from the ferrous metal industry, while ΔCL and structural factors played minor roles; 3) if the policies for the 13th five-year plan period are enforced vigorously, CO2 emissions from China's ferrous metal industry could be reduced by 724.07 Mt in 2020. Policy suggestions are proposed for emission abatement in China's ferrous metal industry.

The driving forces and potential mitigation of energy-related CO2 emissions in China's metal industry

Utilizing the logarithmic mean Divisia index (LMDI) method, this paper decomposes the CO2 emissions of China's metal industry into five factors, namely, industrial output, industrial structure, energy intensity, energy consumption structure, and carbon dioxide emissions coefficient. Then, a scenario analysis is used to predict future CO2 emissions and estimate the emission mitigation potential from 2016 to 2020. The results indicate that (1) from 2000 to 2015, China's metal industry witnessed substantial growth in CO2 emissions, showing an increase of 1015.56 million tons (Mt). (2) Of the five driving factors, the industrial output effect was mainly responsible for CO2 emissions growth, with a contribution ratio of 245.51% over the total CO2 emission change, with other driving factors held constant. In contrast, the energy intensity decline was decisive for reducing CO2 emission, followed by the industrial structure. (3) The energy consumption structure had the weakest effect on CO2 emission changes and presented an overall positive effect with some volatility. (4) The CO2 emission mitigation potential under the moderate and aggressive emission mitigation scenarios is predicted to be 219.30 and 1445.26 Mt in 2020, respectively. These research findings propose that the Chinese government should take full advantage of the mitigating factors (i.e., decreasing energy intensity and industrial restructuring), paying particular attention to the subsector of the smelting and pressing of ferrous metals, and strive for breakthroughs.

Driving forces and mitigation potential of global CO2 emissions from 1980 through 2030: Evidence from countries with different income levels

To mitigate global carbon dioxide (CO2) emissions in an effective manner, it is essential to identify the driving forces and estimate the reduction potential of changes to CO2 emissions. Using an extended logarithmic mean Divisia index (LMDI) method, this study decomposes the changes in global emissions between 1980 and 2015 with consideration of different income levels; it also reports on scenario analysis of the global emissions reduction potential up to the year 2030 to explore feasible mitigation pathways. The results suggest that the key driving force responsible for promoting global emissions from 1980 through 2015 is income, while energy intensity is the most significant factor in inhibiting global emissions. Furthermore, the countries with the largest reductions in global emissions are mainly upper-middle-income (UMI) countries. The key driving forces of emissions changes in countries with different income levels offer mixed results. In addition, the forecast results indicate that the future emissions reduction potential across the globe is significant and that UMI countries offer the greatest emissions mitigation potential. Finally, this study provides several targeted policy suggestions for reducing emissions across the globe.

Appraising the environmental benefits of ride-sharing: The Paris region case study

This paper investigates the environmental benefits of ride-sharing through its CO2 emission mitigation potential. Ride-sharing is expected to substantially decrease CO2 emissions by raising vehicle occupancy, thus mechanically reducing the number of vehicles on the road. Yet, as ride-sharing entails both a decrease in travel (monetary) costs and in travel times (inasmuch as it reduces road congestion), it is likely to make the car more attractive ultimately. This could result in mode switching in the short run (as travelers forsake public transport or active modes for car), as well as in longer distances travelled in the medium run. In the long run, people could even take advantage of the easier travel conditions to relocate further within the metropolitan area. To account for these rebound effects, we develop an integrated land-use transport model. This intends to capture the effects of ride-sharing on the whole household decision process regarding transport and residential location. The model is applied to the Paris region, with several ride-sharing scenarios for year 2030. While ride-sharing does indeed strongly reduce CO2 emissions, we find substantial rebound mechanisms. In contrast to the (naïve) expectation that raising vehicle occupancy by 50% would reduce CO2 emissions by 33%, the various rebound effects end up dividing the CO2 emission savings by a factor ranging from 2 to 3 depending on the day period considered (i.e. the morning or evening peak period). The rebound mechanisms - the mode switching, distance and relocation effects - should therefore be heeded. Some policy recommendations are provided to develop ride-sharing while curbing these unintended effects.

CO2 Emission Performance, Mitigation Potential, and Marginal Abatement Cost of Industries Covered in China’s Nationwide Emission Trading Scheme: A Meta-Frontier Analysis

China’s nationwide emission trading scheme (CN-ETS) is scheduled to be launched in 2017. It is of great urgency and necessity to obtain a good understanding of the participating sectors of CN-ETS in terms of energy utilization and CO2 emissions. In this regard, it should be noted that the findings may be biased without taking industry heterogeneity into consideration. To this end, a meta-frontier framework with the directional distance function is employed to estimate the CO2 emission performance (CEP), mitigation potential (MP), and marginal abatement cost (MAC) at sector levels under the meta-frontier and the group-frontier. The results indicate that significant disparities in the CEP, MP, and MAC exist under both frontiers among various sectors, and the sectoral distributions of CEP, MP, and MAC are found to be different between the two frontiers. Additionally, the differences between the two frontiers in terms of CEP, MP, and MAC are considerable, and exhibit unequal distributions among these sectors. Notably, MAC under both frontiers and the difference between them are found to be significantly correlated with the carbon intensity. Finally, policy implications are provided for the government and participating enterprises, respectively.

Reducing global CO2 emissions with the technologies we have

The energy intensities of the various industrial sectors differ considerably across countries. This suggests a potential for emissions reductions through improved accessibility to efficient technologies. This paper estimates an upper-bound CO2 emission mitigation potential that could theoretically be achieved by improved access to efficient technologies in industrial sectors. We develop a linear optimization framework that facilitates the exchange of sectoral production technologies based on the World Input-Output Database (WIOD), assuming perfect substitutability of technologies and homogeneity within economic sectors, while ignoring barriers to technological adoption and price driven adjustments. We consider the full global supply chain network and multiple upstream production inputs in addition to energy demand. In contrast to existing literature our framework allows to consider supply chain effects of technology replacements. We use our model to calculate emission reduction potentials for varying levels of access to technology. If best practice technologies were made available globally, CO2 emissions could theoretically be reduced by more than 10 gigatons (Gt). In fact, even second-tier production technologies would create significant global reduction potentials. We decompose sectoral emission reductions to identify contributions by changes in energy intensity, supply chain effects and changes in carbon intensities. Excluding the latter, we find that considering supply chain effects increases total mitigation potentials by 14%. The largest CO2 emission reduction potentials are found for a small set of developing countries.

Mitigation potential of CO2 emissions from modal shift induced by subsidy in hinterland container transport

A comprehensive analytical framework is presented to assess the potential modal shift (MS) from road transport to rail/water transport and resulting carbon dioxide (CO2) emission mitigation induced by a subsidy policy in port-hinterland transport. In this framework, a modal share model based on a random coefficient logit model and an activity-based method are used to analyze the contribution of an incentive policy to the potential MS and corresponding CO2 emission mitigation. Stated preference survey, face-to-face interviews, and group discussions are employed to obtain the essential data. Case study result shows that a CO2 emission mitigation of 2,586.88t may be achieved with a subsidy of 200 RMB/TEU (Renminbi/20-feet equivalent unit) to the shippers who choose the road-rail combined transport chain in Yiwu City. Compared with the business-as-usual scenario without subsidy, the subsidy policy scenario can achieve a 3.2% MS from a road-only transport chain to a road-rail combined transport chain, as well as a 2.07% CO2 emission mitigation in the Yiwu-Ningbo container transport corridor. This finding reveals that the subsidies can serve as short-term solutions, but a policy package, including financial, technological, operational, and managerial measures, is required as a long-term strategy.