Direct Greenhouse Gas Emissions Research Articles

Prediction and analysis of the seasonal performance of tri-generation and CO2 refrigeration systems in supermarkets

A modern supermarket energy control system has a concurrent need for electricity, space heating or cooling, and food refrigeration. The power supply to the supermarket is primarily from the national grid, where losses in efficiency are due to the processes of energy conversion and transmission. Combined heat and power (CHP) offers the potential to locally produce electrical power and heating which could save energy and reduce CO2 emissions in the long run. During the summer months, as the space heating requirement in a supermarket is relatively small, the energy efficiency of a CHP installation can be improved by using excess thermal energy to drive a sorption refrigeration system to provide space cooling or refrigeration. This process is also known as tri-generation. In recent years, the use of CO2 as a refrigerant in supermarkets has received considerable attention due to its negligible contribution to direct greenhouse gas emissions and excellent thermophysical and heat transfer properties. Consequently, the application of a tri-generation system in a supermarket with CO2 refrigeration merits further investigation.In this paper, to evaluate the performance of a tri-generation system in the supermarket, a previously tested 80kWe microturbine device was applied into an operational supermarket to generate power and provide space heating and cooling through exhaust heat. The performance evaluation and comparison for this tri-generation application is based on the prediction from an integrated model of supermarket energy control, cascade CO2 refrigeration and tri-generation systems. The results from this simulation demonstrate the feasibility of a tri-generation system in the supermarket and pave the way for further consideration towards designs in future.

Sustainable bioenergy production from marginal lands in the US Midwest

Legislation on biofuels production in the USA and Europe is directing food crops towards the production of grain-based ethanol, which can have detrimental consequences for soil carbon sequestration, nitrous oxide emissions, nitrate pollution, biodiversity and human health. An alternative is to grow lignocellulosic (cellulosic) crops on 'marginal' lands. Cellulosic feedstocks can have positive environmental outcomes and could make up a substantial proportion of future energy portfolios. However, the availability of marginal lands for cellulosic feedstock production, and the resulting greenhouse gas (GHG) emissions, remains uncertain. Here we evaluate the potential for marginal lands in ten Midwestern US states to produce sizeable amounts of biomass and concurrently mitigate GHG emissions. In a comparative assessment of six alternative cropping systems over 20 years, we found that successional herbaceous vegetation, once well established, has a direct GHG emissions mitigation capacity that rivals that of purpose-grown crops (-851 ± 46 grams of CO(2) equivalent emissions per square metre per year (gCO(2)e m(-2) yr(-1))). If fertilized, these communities have the capacity to produce about 63 ± 5 gigajoules of ethanol energy per hectare per year. By contrast, an adjacent, no-till corn-soybean-wheat rotation produces on average 41 ± 1 gigajoules of biofuel energy per hectare per year and has a net direct mitigation capacity of -397 ± 32 gCO(2)e m(-2) yr(-1); a continuous corn rotation would probably produce about 62 ± 7 gigajoules of biofuel energy per hectare per year, with 13% less mitigation. We also perform quantitative modelling of successional vegetation on marginal lands in the region at a resolution of 0.4 hectares, constrained by the requirement that each modelled location be within 80 kilometres of a potential biorefinery. Our results suggest that such vegetation could produce about 21 gigalitres of ethanol per year from around 11 million hectares, or approximately 25 per cent of the 2022 target for cellulosic biofuel mandated by the US Energy Independence and Security Act of 2007, with no initial carbon debt nor the indirect land-use costs associated with food-based biofuels. Other regional-scale aspects of biofuel sustainability, such as water quality and biodiversity, await future study.

Biofuel production on the margins

An analysis shows that fuel made from wild, herbaceous vegetation grown on land currently unsuitable for cultivating field crops could contribute substantially to the United States' targets for biofuel production. See Letter p.514 Productive agricultural land that could otherwise be used to produce much-needed food crops is being diverted towards grain-based ethanol production in both Europe and the United States, partly in response to government legislation. An alternative is to grow cellulosic crops on so-called marginal lands. An evaluation of the potential of marginal lands in the Midwestern United States to produce biofuel while mitigating direct greenhouse gas emissions now finds that they have the capacity to produce a significant amount of biofuel energy without the initial carbon debt and indirect land-use costs associated with food-based biofuels.

Greenhouse Gas Emissions for Refrigerant Choices in Room Air Conditioner Units

In this work, potential replacement refrigerants for window-mounted room air conditioners (RACs) in the U.S. have been evaluated using a greenhouse gas (GHG) emissions analysis. CO(2)-equivalent emissions for several hydrofluoroethers (HFEs) and other potential replacements were compared to the most widely used refrigerants today. Included in this comparison are pure refrigerants that make up a number of hydrofluorocarbon (HFC) mixtures, pure hydrocarbons, and historically used refrigerants such as propane and ammonia. GHG emissions from direct and indirect sources were considered in this thermodynamic analysis. Propylene, dimethyl ether, ammonia, R-152a, propane, and HFE-152a all performed effectively in a 1 ton window unit and produced slightly lower emissions than the currently used R-22 and R-134a. The results suggest that regulation of HFCs in this application would have some effect on reducing emissions since end-of-life emissions remain at 55% of total refrigerant charge despite EPA regulations that mandate 80% recovery. Even so, offsite emissions due to energy generation dominate over direct GHG emissions and all the refrigerants perform similarly in totals of indirect GHG emissions.

Carbon and nitrogen mass balance during flue gas treatment with Dunaliella salina cultures

The biotreatment of flue gases with algae cultures is a promising option to sequestrate CO2, yet the emission of other greenhouse gases (GHG) from the cultures can hamper their environmental benefit. Quantitative data on the sequestration potential for CO2 and NO (x) in relation to the direct production of CH4 and N2O are urgently required. The present study assessed the flows of carbon (C) and nitrogen (N) through cultures of the green alga Dunaliella salina, supplied with biodiesel flue gas, by means of mass balancing. D. salina was grown in artificially lighted, field- (42-L bubble column reactor) and laboratory-scale cultures (23 A degrees C, pH 7.5). In the bubble column reactor, algae grew with an average specific growth rate of 0.237 day(-1) under flue gas supplementation (6.3 % (v/v) CO2, 1.2 ppmv NO (x) ), and CO2 was retained to 39 % in the system. The specific sequestration rate for CO2 was low, with 0.13 g CO2 L-1 day(-1). Cultures emitted up to 13.03 mu g CH4 L-1 day(-1) and 4261 mu g N2O L-1 day(-1). The moderate retention of NO (x) -N was outweighed by emissions of N2O-N, and total N in the system decreased by 15.48 % during the 9-day trial. Results suggest that GHG production was mainly the outcome of anaerobic microbial processes and their emission was lower in pre-sterilized cultures. Under the tested conditions, up to six times more CO2 equivalents were emitted during flue gas treatment. Therefore, the direct GHG emissions of algae culture systems, intended for flue gas treatment (i.e. open ponds) need to be reviewed critically.

Including CO2 implications of land occupation in LCAs—method and example for livestock products

Purpose Until recently, life cycle assessments (LCAs) have only addressed the direct greenhouse gas emissions along a process chain, but ignored the CO2 emissions of land-use. However, for agricultural products, these emissions can be substantial. Here, we present a new methodology for including the implications of land occupation for CO2 emissions to realistically reflect the consequences of consumers’ decisions.

An integrated analytical framework for quantifying the LCOE of waste-to-energy facilities for a range of greenhouse gas emissions policy and technical factors

This study presents a novel integrated method for considering the economics of waste-to-energy (WTE) facilities with priced greenhouse gas (GHG) emissions based upon technical and economic characteristics of the WTE facility, MSW stream, landfill alternative, and GHG emissions policy. The study demonstrates use of the formulation for six different policy scenarios and explores sensitivity of the results to ranges of certain technical parameters as found in existing literature. The study shows that details of the GHG emissions regulations have large impact on the levelized cost of energy (LCOE) of WTE and that GHG regulations can either increase or decrease the LCOE of WTE depending on policy choices regarding biogenic fractions from combusted waste and emissions from landfills. Important policy considerations are the fraction of the carbon emissions that are priced (i.e. all emissions versus only non-biogenic emissions), whether emissions credits are allowed due to reducing fugitive landfill gas emissions, whether biogenic carbon sequestration in landfills is credited against landfill emissions, and the effectiveness of the landfill gas recovery system where waste would otherwise have been buried. The default landfill gas recovery system effectiveness assumed by much of the industry yields GHG offsets that are very close to the direct non-biogenic GHG emissions from a WTE facility, meaning that small changes in the recovery effectiveness cause relatively larger changes in the emissions factor of the WTE facility. Finally, the economics of WTE are dependent on the MSW stream composition, with paper and wood being advantageous, metal and glass being disadvantageous, and plastics, food, and yard waste being either advantageous or disadvantageous depending upon the avoided tipping fee and the GHG emissions price.

Financial development, investor protection, and corporate commitment to sustainability

PurposeThe purpose of the study is to investigate whether the relationship between financial development/investor protection and corporate commitment to sustainability is related to social contagion, neighborhood effect, and community effect.Design/methodology/approachThe study applies correlation analysis, difference tests, and regression model to a sample comprised of 369 large firms listed on FTSE Global 500 covering 11 industries, located in 31 countries. This paper examines three country‐level variables, financial development index, shareholder rights index, and strength of investor protection, and five corporate commitment to sustainability measures, Carbon Disclosure Leadership Index, Greenhouse Gas (GHG) emissions (direct, electricity indirect, and other indirect GHG emissions), and the corresponding carbon intensity.FindingsThe results support the view that the relationship between financial development/investor protection and corporate commitment to sustainability is associated with social contagion, neighborhood effect, and community effect. Companies are more willing to commit to carbon disclosure for countries with higher financial development. Corporate commitment to sustainability is lower if neighbor countries' financial development or shareholder rights are high. Similarly, companies place less strategic importance on climate change issues if their community countries protect investors better, notwithstanding their relatively low level of other indirect GHG emissions.Research limitations/implicationsFuture research may build on this research by supplementing the current data with more variables such as domestic financial sector liberalization or measures, such as business environment, financial stability, and size, depth, and access. The negative relationship between commitment to sustainability and investor rights suggests that investor rights and commitment to sustainability are singing different tunes. Corporate commitment to sustainability does not keep pace with investor rights especially for countries with better shareholder rights or investor protection.Originality/valueThis study provides a new perspective on the relationship between financial development/investor protection and commitment to sustainability. This study contributes to the existing literature by using five measures of corporate commitment to sustainability based on firm‐specific data using a sample of the FTSE Global 500. This paper provides a better understanding of the relationship between country‐level characteristics and commitment to sustainability in an environment where global integration is relatively high.

The relative greenhouse gas impacts of realistic dietary choices

The greenhouse gas (GHG) emissions embodied in 61 different categories of food are used, with information on the diet of different groups of the population (omnivorous, vegetarian and vegan), to calculate the embodied GHG emissions in different dietary scenarios. We calculate that the embodied GHG content of the current UK food supply is 7.4kg CO2eperson−1day−1, or 2.7tCO2eperson−1y−1. This gives total food-related GHG emissions of 167MtCO2e (1Mt=106 metric tonnes; CO2e being the mass of CO2 that would have the same global warming potential, when measured over 100 years, as a given mixture of greenhouse gases) for the entire UK population in 2009. This is 27% of total direct GHG emissions in the UK, or 19% of total GHG emissions from the UK, including those embodied in goods produced abroad. We calculate that potential GHG savings of 22% and 26% can be made by changing from the current UK-average diet to a vegetarian or vegan diet, respectively. Taking the average GHG saving from six vegetarian or vegan dietary scenarios compared with the current UK-average diet gives a potential national GHG saving of 40MtCO2ey−1. This is equivalent to a 50% reduction in current exhaust pipe emissions from the entire UK passenger car fleet. Hence realistic choices about diet can make substantial differences to embodied GHG emissions.

Greenhouse gas emissions tool

Power plants were the largest stationary source of direct greenhouse gas (GHG) emissions in the United States in 2010, according to data from the Environmental Protection Agency's (EPA) GHG Reporting Program, the agency announced on 11 January. The GHG data set, which includes reports from more than 6700 facilities, provides information that the public can search to identify local sources of emissions and that businesses can use to track emissions. Gina McCarthy, assistant administrator for EPA's Office of Air and Radiation, said the program is “a transparent, powerful data resource available to the public” and that it provides “a critical tool” for businesses and others to find efficiencies to reduce emissions.

Energy-Dominated Local Carbon Emissions in Beijing 2007: Inventory and Input-Output Analysis

For greenhouse gas (GHG) emissions by Beijing economy 2007, a concrete emission inventory covering carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) is presented and associated with an input-output analysis to reveal the local GHG embodiment in final demand and trade without regard to imported emissions. The total direct GHG emissions amount to 1.06E + 08 t CO2-eq, of which energy-related CO2 emissions comprise 90.49%, non-energy-related CO2 emissions 6.35%, CH4 emissions 2.33%, and N2O emissions 0.83%, respectively. In terms of energy-related CO2 emissions, the largest source is coal with a percentage of 53.08%, followed by coke with 10.75% and kerosene with 8.44%. Sector 26 (Construction Industry) holds the top local emissions embodied in final demand of 1.86E + 07 t CO2-eq due to its considerable capital, followed by energy-intensive Sectors 27 (Transport and Storage) and 14 (Smelting and Pressing of Ferrous and Nonferrous Metals). The GHG emissions embodied in Beijing's exports are 4.90E + 07 t CO2-eq, accounting for 46.01% of the total emissions embodied in final demand. The sound scientific database totally based on local emissions is an important basis to make effective environment and energy policies for local decision makers.

우리나라 광역지방자치단체의 직접 및 간접 CO2배출량의 비교 연구: 에너지 부문을 중심으로

In this study, the urban CO2 emission based on energy consumption (Coal, Petroleum, Electricity, and City Gas) in 16 provincial and metropolitan city governments in South Korea was evaluated. For calculation of the urban CO2 emission, direct and indirect emissions were considered. Direct emissions refer to generation of greenhouse gas (GHG) on-site from the energy consumption. Indirect emissions refer to the use of resources or goods that discharge GHG emissions during energy production. The total GHG emission was 497,083 thousand ton CO2eq. in 2007. In the indirect GHG emission, about 240,388 thousand ton CO2eq. was occurred, as 48% of total GHG emission. About 256,694 thousand ton CO2eq. (52% of total GHG emissions) was produced in the direct GHG emission. This amount shows 13% difference with 439,698 thousand ton CO2eq. which is total national GHG emission data using current calculation method. Local metropolitan governments have to try to get accuracy and reliability for quantifying their GHG emission. Therefore, it is necessary to develop and use Korean emission factors than using the IPCC (Intergovernmental Panel on Climate Change) emission factors. The method considering indirect and direct GHG emission, which is suggested in this study, should be considered and compared with previous studies.

Options to reduce greenhouse gas emissions during wastewater treatment for agricultural use

Treatment of primarily-domestic sewage wastewater involves on-site greenhouse gas (GHG) emissions due to energy inputs, organic matter degradation and biological nutrient removal (BNR). BNR causes both direct emissions and loss of fertilizer value, thus eliminating possible reduction of emissions caused by fertilizer manufacture. In this study, we estimated on-site GHG emissions under different treatment scenarios, and present options for emission reduction by changing treatment methods, avoiding BNR and by recovering energy from biogas. Given a typical Israeli wastewater strength (1050mg CODl−1), the direct on-site GHG emissions due to energy use were estimated at 1618 and 2102g CO2-eqm−3, respectively, at intermediate and tertiary treatment levels. A potential reduction of approximately 23–55% in GHG emissions could be achieved by fertilizer preservation and VS conversion to biogas. Wastewater fertilizers constituted a GHG abatement potential of 342g CO2-eqm−3. The residual component that remained in the wastewater effluent following intermediate (oxidation ponds) and enhanced (mechanical–biological) treatments was 304–254g CO2-eqm−3 and 65–34g CO2-eqm−3, respectively. Raw sludge constituted approximately 47% of the overall wastewater fertilizers load with an abatement potential of 150g CO2-eqm−3 (385kg CO2-eq dry tonne−1). Inasmuch as anaerobic digestion reduced it to 63g CO2-eqm−3 (261kg CO2-eq dry tonne−1), the GHG abatement gained through renewable biogas energy (approx. 428g CO2-eqm−3) favored digestion. However, sludge composting reduced the fertilizer value to 17g CO2-eqm−3 (121kg CO2-eq dry tonne−1) or less (if emissions, off-site inputs and actual phytoavailability were considered). Taking Israel as an example, fully exploiting the wastewater derived GHG abatement potential could reduce the State overall GHG emissions by almost 1%. This demonstrates the possibility of optional carbon credits which might be exploited in the construction of new wastewater treatment facilities, especially in developing countries.

Embodiment Analysis for Greenhouse Gas Emissions by Chinese Economy Based on Global Thermodynamic Potentials

This paper considers the Global Thermodynamic Potential (GTP) indicator to perform a unified assessment of greenhouse gas (GHG) emissions, and to systematically reveal the emission embodiment in the production, consumption, and international trade of the Chinese economy in 2007 as the most recent year available with input-output table and updated inventory data. The results show that the estimated total direct GHG emissions by the Chinese economy in 2007 amount to 10,657.5 Mt CO2-eq by the GTPs with 40.6% from CH4 emissions in magnitude of the same importance as CO2 emissions. The five sectors of Electric Power/Steam and Hot Water Production and Supply, Smelting and Pressing of Ferrous and Nonferrous Metals, Nonmetal Mineral Products, Agriculture, and Coal Mining and Dressing, are responsible for 83.3% of the total GHG emissions with different emission structures. The demands of coal and coal-electricity determine the structure of emission embodiment to an essential extent. The Construction sector holds the top GHG emissions embodied in both domestic production and domestic consumption. The GHG emission embodied in gross capital formation is more than those in other components of final demand characterized by extensive investment and limited household consumption. China is a net exporter of embodied GHG emissions, with a remarkable share of direct emission induced by international trade, such as textile products, industrial raw materials, and primary machinery and equipment products exports. The fractions of CH4 in the component of embodied GHG emissions in the final demand are much greater than those fractions calculated by the Global Warming Potentials, which highlight the importance of CH4 emissions for the case of China and indicate the essential effect of CH4 emissions on global climate change. To understand the full context to achieve GHG emission mitigation, this study provides a new insight to address China’s GHG emissions status and hidden emission information induced by the final demand to the related policy-makers.

Whole-farm systems modelling of greenhouse gas emissions from pastoral suckler beef cow production systems

A whole farm BEEF systems Greenhouse gas Emissions Model (BEEFGEM) was developed to determine the effect of varying management practices on greenhouse gas (GHG) emissions from pastoral beef production systems. BEEFGEM simulates two categories of GHG emissions: firstly, the direct GHG emissions of methane, nitrous oxide and carbon dioxide from on-farm livestock production activities and secondly, indirect GHG emissions associated with inputs used on the farm and GHG emissions associated with nitrate leaching and ammonia volatilisation. The aim of this work was to investigate the effect of alternative production systems at farm level on GHG emissions. Greenhouse gas emissions were modelled for five contrasting beef production systems, one based on average farm conditions in Ireland and four based on research farm conditions. Both direct and total GHG emissions per hectare increased with increasing stocking rate for all scenarios tested. However, increasing stocking rate led to a reduction in GHG emissions per kg beef carcass, albeit with higher levels of production efficiency. At moderate stocking rates, increasing stocking rate further resulted in an increase in GHG emissions per kg beef carcass. Cattle production systems finishing males as bulls had lower GHG emissions than production systems finishing males as steers and thus, the lowest GHG emissions per kg beef carcass were achieved for bull beef production systems at moderate stocking rates which had direct and total system GHG emissions of 15.7 and 18.9 kg CO 2e/kg beef carcass, respectively. Bull beef production systems at high stocking rates were most profitable. The highest GHG emissions were for the scenario representing average farm conditions in Ireland with direct and total emissions of 19.0 and 23.1 kg CO 2e/kg beef carcass, respectively. This was also the least profitable scenario.

Long-Term Trends and Opportunities for Managing Regional Water Supply and Wastewater Greenhouse Gas Emissions

Greenhouse gas emissions are likely to rise faster than growth in population and more than double for water supply and wastewater services over the next 50 years in South East Queensland (SEQ), Australia. New sources of water supply such as rainwater tanks, recycled water, and desalination currently have greater energy intensity than traditional sources. In addition, direct greenhouse gas emissions from reservoirs and wastewater treatment and handling have potentially the same magnitude as emissions from the use of energy. Centralized and decentralized water supply and wastewater systems are considered for a scenario based upon a government water supply strategy for the next 50 years. Many sources of data have large uncertainties which are estimated following the IPCC Good Practice Guidelines. Important sources of emissions with large uncertainties such as rainwater tanks and direct emissions were identified for further research and potential mitigation of greenhouse gas emissions.

An Environmentally Extended Input-Output Analysis to Support Sustainable Use of Forest Resources

The use of environmentally extended input-output analysis was demonstrated for quantifying the overall sustainability impacts of forest industries in the Finnish economy in 2005. Direct greenhouse gas emission, land use, employment and import impacts of economic sectors were transformed into impact intensities of products. The intensities were used to construct a final demand based emission inventory demonstrating the relative importance of export, investment and consumption activities in causing environmental and social impacts. The calculations were presented using an aggregated input-ouput table, which makes it possible to repeat the calculations using standard spreadsheet software. Therefore the study can be used as an accessible primer to the use of input-output methods in sustainability assessment.

Characterization of bismuth telluride aerogels for thermoelectric applications

ABSTRACTRefrigeration, air conditioning, and other cooling requirements in buildings, industry, and transportation sectors account for about 10 quads of U.S. primary energy consumption. Therefore, advanced technologies for space cooling in buildings and vehicles – as well as for refrigeration in residential, commercial, and industrial applications – that are more energy efficient, avoid net direct greenhouse gas emissions, reduce lifecycle costs, and can impact large markets are needed. Although current technologies are reaching their efficiency limits, thermoelectric (TE) materials can be used for cooling applications and have potential for significant improvements. Compared to traditional bulk phase TE materials, literature results suggest that nanometer-scale materials allow additional opportunities to improve the efficiency of TE materials. Aerogels are one type of nano-material that offers opportunities to increase the efficiency of TE materials by controlling particle size, particle composition and by reducing the thermal conductivity. Bismuth telluride (Bi2Te3) is the most studied TE material and our objective was to produce bismuth telluride aerogels with controlled microstructures and thermal conductivities to increase the TE figure of merit. Aspen Aerogels developed a novel synthesis method to prepare Bi2Te3 aerogels using the principles of colloidal chemistry and sol-gel chemistry. The reaction conditions were investigated and optimized so that gels could be obtained at low reaction temperatures. The gels were aged and dried using supercritical CO2. The aerogels were characterized by BET, XRD, and SEM. The best aerogels were hot pressed and Seebeck coefficients were determined. The synthetic approach developed and the properties of the aerogels will be presented and compared with Bi2Te3 aerogels and materials prepared by other methods.

Greenhouse gas emissions in China 2007: Inventory and input–output analysis

For greenhouse gas (GHG) emissions by the Chinese economy in 2007 with the most recent statistics availability, a concrete inventory covering CO 2, CH 4, and N 2O is composed and associated with an input–output analysis to reveal the emission embodiment in final consumption and international trade. The estimated total direct GHG emission amounts to 7456.12 Mt CO 2-eq by the commonly referred IPCC global warming potentials, with 63.39% from energy-related CO 2, 22.31% from non-energy-related CO 2, 11.15% from CH 4 and 3.15% from N 2O. Responsible for 81.32% of the total GHG emissions are the five sectors of the Electric Power/Steam and Hot Water Production and Supply, Smelting and Pressing of Ferrous and Nonferrous Metals, Nonmetal Mineral Products, Agriculture, and Coal Mining and Dressing, with distinctive emission structures. The sector of Construction holds the top GHG emissions embodied in both domestic production and consumption, and the emission embodied in gross capital formation is prominently more than those in other components of the final consumption characterized by extensive investment in contrast to limited household consumption. China is a net exporter of embodied GHG emissions, with emissions embodied in exports of 3060.18 Mt CO 2-eq, in magnitude up to 41.04% of the total direct emission.

Scenario analysis on alternative fuel/vehicle for China’s future road transport: Life-cycle energy demand and GHG emissions

The rapid growth of vehicles has resulted in continuing growth in China’s oil demand. This paper analyzes future trends of both direct and life cycle energy demand (ED) and greenhouse gas (GHG) emissions in China’s road transport sector, and assesses the effectiveness of possible reduction measures by using alternative vehicles/fuels. A model is developed to derive a historical trend and to project future trends. The government is assumed to do nothing additional in the future to influence the long-term trends in the business as usual (BAU) scenario. Four specific scenarios are used to describe the future cases where different alternative fuel/vehicles are applied. The best case scenario is set to represent the most optimized case. Direct ED and GHG emissions would reach 734 million tonnes of oil equivalent and 2384 million tonnes carbon dioxide equivalent by 2050 in the BAU case, respectively, more than 5.6 times of 2007 levels. Compared with the BAU case, the relative reductions achieved in the best case would be 15.8% and 27.6% for life cycle ED and GHG emissions, respectively. It is suggested for future policy implementation to support sustainable biofuel and high efficient electric-vehicles, and the deployment of coal-based fuels accompanied with low-carbon technology.