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As urbanization accelerates worldwide, substantial energy and services are required to meet the demand from cities, making cities major contributors to adverse environmental consequences. To bridge the knowledge gap in the absence of fine-grained city-level climate protection measures due to data availability and accuracy, this study provides a detailed carbon emission inventory for analyzing the monthly fluctuations based on citizens’ daily consumption behaviors. Here, carbon emissions embodied in approximately 500 household consumption items were calculated in 47 prefectural-level cities in Japan from 2011 to June 2021. We analyzed the results considering the regional, seasonal, demand, and emission way-specific aspects, and compared the emission before and during the COVID-19 pandemic. Notably, the carbon footprints during the pandemic were consistent with the previous level despite downtrends in specific categories. This study provides an example of utilizing city-level emission data to improve household green consumption behavior as references for enriching city-level decarbonization paths.

The residential sector is one of the major sources of greenhouse gases, and as such it is key for achieving decarbonization targets. However, very diverse household characteristics affect energy use and emissions at the household level. Furthermore, demographic transitions characterized by ageing and shrinking in both total and household size can have enduring effects for some of these household characteristics at the societal level. Here, we explore how demographic transitions in Japan may affect the long-term emissions in the residential sector based on the scenarios to the year 2040. First, we draw from a large-scale survey conducted by the Japanese government (9,996 households) to develop a nuanced typology of households using an integrated clustering approach. This helps us identify high variability in emissions and adoption of emission mitigation technologies between households with different characteristics. We found that household size and age both play important role in terms of emissions. Finally, through different scenarios we identify that indeed the projected demographic transitions with the increasing prevalence of smaller and more elderly households in Japan will likely hinder emission mitigation in the residential sector, imposing significant constraints for achieving decarbonization in the long-term.

Unexpected events such as economic crises and natural disasters can have profound implications for energy systems and climate change mitigation efforts at different levels. Here we explore the national and regional carbon emission patterns (and their drivers) for the main economic sectors in Japan between 2007 and 2015, a period shaped by the 2008 financial crisis and the 2011 Tohoku Earthquake. Following the 2011 earthquake the previously decreasing regional emissions patterns started increasing in practically all regions except Hokkaido. This was mainly due to growing coal use particularly in the Kyushu, Chugoku and Kansai regions. Furthermore, most regions experienced shifts in the dominance of different drivers of emissions over time, with a stronger initial impact from economic effects after the 2008 financial crisis, followed by energy structure after the 2011 earthquake, and then by economic effects and energy intensity. These results offer a more nuanced understanding of how individual events can affect emissions at different periods and levels (national vs. regional) to inform the design of climate change mitigation strategies. Exogenous events in Japan had lasting impacts on the energy mix and on CO2 emissions at the national and regional levels. The 2008 financial crisis mainly affected the economy, whereas the 2011 earthquake influenced energy structure, though the actual impacts vary between regions.

We investigate the automobile preferences of consumers and evaluate financial incentives designed to promote automobiles of higher fuel economy in Japan from sales data. We explore two different groups of consumers, namely, general consumers and selective consumers, according to their fuel economy preferences. Then we estimate the effectiveness of financial incentives and the price sensitivity of such incentives to different groups of consumers. We use ordered logit, linear regression, and simultaneous equations. Estimates suggest that only tax incentives are effective for general consumers, thereby implying a need to improve Japanese policies.

Accelerating global warming has suggested the importance of controlling greenhouse gas emissions associated with human activities. In striving to fulfill the Paris Agreement, China has announced its Intended Nationally Determined Contributions (INDCs) aimed at reducing its carbon dioxide (CO2) emission intensity by 60–65% in 2030 against the level of 2005. However, China’s INDCs cannot be fulfilled without formulating appropriate schemes for the allocation of carbon emission allowance (CEA) at sub-national scales. To help close the gap in our knowledge, this paper starts with measuring the overall CEA of China by 2030, and then proposes a science-based scheme for CEA allocation by developing an improved zero sum gains-data envelopment analysis (ZSG-DEA) model. It demonstrates that the final CEA of some northern provinces can be cut down as compared to their initial shares and, conversely, most southern provinces experience an increase in their CEA. Comparing the final share of CEA by province with current carbon emissions, we observe that provinces with abundant energy reserves, such as Shanxi, Inner Mongolia and Shaanxi, tend to be operating in a state of overshoot in terms of space for carbon emissions (SCE). In contrast, there remains SCE when it comes to Guangdong, Hunan, Fujian, etc. The remaining provinces, such as Heilongjiang, Hebei and Ningxia, are close to the break-even point. In view of the differing SCE of individual provinces, common but differentiated policies for CO2 emission control would be the key to achieving China’s INDCs. The research findings lay a scientific basis for the Chinese government to make its INDCs come true through inter-provincial collaboration on emission reduction, but also serve as a reference for fueling further scientific discussions and development of schemes for the allocation of responsibility for carbon emissions at multiple scales within and beyond China.

Residential consumption produces carbon emissions through the combustion of primary energy (directly) as well as through the consumption of goods and services (indirectly). To capture the latter indirect emissions, it is common to use producer-price based input-output analysis associated with household monetary expenditures. However, producer-price input-output tables usually do not account for economic transactions and energy flows at the margin. To better understand household indirect emissions from the purchaser perspective, there is a need for a modified input–output modeling approach. To that end, this study attempts to measure the carbon footprint of households in the Tokyo Metropolis, Japan by integrating monthly household consumption inventories into an input–output table of Tokyo. By doing so, the carbon footprint was estimated to be 0.76 tC per household and the total estimated marginal carbon emissions for Tokyo is up to 0.56 MtC. A sectoral breakdown of the total emission coefficients is provided based on purchaser prices and temporal variations in emissions. Findings indicate that within household consumption, Clothing and Services categories contributed most to marginal emissions. The conclusions drawn in this paper are pertinent and policy relevant because they provide relatively accurate information compared to the status quo to inform appropriate policies for guiding residential consumption at the city scale of resolution.

The transport sector is a major contributor to anthropogenic climate change through the emissions of large amounts of greenhouse gases from fossil fuel combustion. Private vehicles account for almost half of the transport energy demand, and are thus a major target for climate change mitigation efforts. However, emissions from private vehicles can have large variability due to various geographic, demographic and socioeconomic factors. This study aims to understand how such factors affect private vehicle emissions in Japan using a nationally representative survey of household energy consumption (n= 7370) for 2017. The results indicate a large temporal and spatial variability in private vehicle emissions. Annual emissions show three peaks associated with major holiday seasons in winter and summer. Some of the more noteworthy spatial patterns are the higher emissions in prefectures characterized by low population density and mountainous terrain. Income, city size and the fuel-saving driving behavior all have a significant effect on emissions. The results indicate the need for sub-regional and socioeconomically-sensitive mitigation efforts that reflect the very different emission patterns, and the factors affecting them. The strong effect of city size, which is often much more clear-cut than between prefectures, suggests that it is more appropriate to approach transport decarbonization in Japan at the city level.

As cities have an increasingly important role in carbon reduction programs, a good understanding of urban energy usage and associated emissions are hence expected to contribute significantly toward policy aimed at reducing energy use and emissions. In this study, residential carbon footprint is revealed by calculating direct and indirect energy demands. The results show the seasonal variation of each type of energy, as well as carbon emissions leaked across city boundaries. The output indicates that 0.35 tC of emissions were generated per household in Tokyo in 2011, including 0.20 tC generated locally and 0.15 tC generated outside of Tokyo. For carbon leakage, February and October are found to result in the highest total emissions, with leaked emissions found to exceed local emissions from July to October. Based on these results, the obvious solution to reduce residential carbon emissions would be a shift to renewable energy sources away from gas use within Tokyo and power generation outside of Tokyo.

In Japan, the Great East Earthquake caused numerous casualties and the subsequent suspension of operations at the Fukushima Daiichi Nuclear Power Plant continues to have an adverse impact on the national energy supply chain. The structural changes in energy supply have served to reinforce the importance of national emissions accounting in promoting overall CO2 reduction policies. However, traditional approaches for evaluating industrial emissions have been criticized for their production-based perspective, which fails to consider emissions embodied in sectoral indirect consumption. The purpose of this study is therefore to understand the sectoral emission transfer. By applying economic input-output tables, detailed sectoral economic interactions can be usefully identified. It was found that the emissions embodied in final consumption generated largely by households. Besides, although emission intensity of manufacturing sector is extremely high in direct emission, agriculture sector is found to exceed other sectors in indirect emission intensities. From the consumption-side, these findings strongly suggest that a high priority be given to mitigation efforts aimed at reducing residential consumption, whist policy priorities are expected to be located on agriculture-related sectors from production-side. The study hence provides insights into how we can better allocate emissions responsibility and set reduction priorities among major economic sectors.

In the Post-Paris Era, urban emissions have received worldwide attention as cities are considered to be responsible for most of the world’s environmental footprint. A better understanding of urban CO2 emissions and their related carbon footprints offers benefits to policymakers interested in promoting effective and efficient low-carbon solutions. In particular, a clear determination of direct and indirect emissions inventories (that is, identification of emissions related to specific sources) can provide a valuable baseline for the planning, assessing, implementing, and monitoring of urban mitigation actions. Focusing on the Japanese urban residential sector, this paper uses an established urban database and emission database based on global-related input-output analysis to systematically analyze household carbon footprints related to energy demand, targeting both direct and indirect energy-related CO2 emissions in Japan’s megacities. The results reveal the city-specific emissions status of Japan’s three major metropolitan areas, showing, for example, that Tokyo is a source of high direct emissions, while Utsunomiya is a significant source of indirect emissions. The study also tentatively concludes that the depopulation of cities can result in higher per capital emissions, both direct and indirect, as they relate to energy demand. Improved sector and spatially explicit information for better mitigation policymaking and environmental education at the urban level is presented. Valuable insights are offered through an in-depth investigation of the relationship between CO2 emissions and urban socioeconomic activities, benefitting future low-carbon city research and practice.

Cities play a crucial role in the implementation of carbon emission mitigation policies since most CO2 emissions are related to energy consumption in urban areas. Recent years, environmentally extended multi-regional input-output tables (EEMRIO) are emerged to reveal regional environment impact considering upstream supply chains crossing regional boundaries. However, city-scale MRIO has not been fully addressed since more focus has been located on national or prefectural level evaluation. For quantifying city-scale emission considering regional energy flow, we apply the input-output table of Tokyo to evaluate energy consumption at the city scale, and the results provides one of the the most detailed sector classification from a wide range of city emission studies. In Japan, Tokyo is considered to be representative of the contemporary Japanese urban energy structure, and its energy consumption and associated CO2 emissions are of major importance when making city-scale carbon mitigation policies. Here, domestic production for Tokyo and other regions is used to quantify the direct and indirect emissions arising from Tokyo final consumption. Our results are divided into sector-specific and fossil fuel source-specific (coal, crude oil, and natural gas) for both direct and indirect emissions. The major findings are as follows: (1) The transportation sector accounts for the largest share of direct emissions in Tokyo. (2) The energy supply, construction, private service sectors account for the largest share of indirect emissions in Tokyo. (3) There are three scopes of emission responsibility evaluated in this study: direct emission before allocation (BE) as 12.88 MtC, after allocation (AE) as 18.91 MtC, and the total including indirect emissions is 27.24 MtC, which is more than twice the direct emissions before allocation. The detailed and energy consumption and emission inventory may be essential for emission responsibility allocation to overcome geographical boundary, therefore, contributes to varied scales of carbon reduction policies.

Japan needs to improve its residential energy efficiency to reduce energy consumption and thus achieve its greenhouse gas (GHG) emissions reduction targets. Understanding the differences in household behavior and energy use is important to evaluate the effect of energy conservation measures. In this study, the authors propose a new method for household energy use modeling based on questionnaire surveys on home appliances and hot water use. Fifteen-minute residential electricity and heat demand profiles with different seasons, household structures and lifestyles are obtained from the survey results, and compared with available statistical data. The replacement effects of refrigerators, TVs and lighting on residential electricity savings, net present value (NPV) and GHG reductions are evaluated using calculated energy demand. Variations in household energy use are considered under different change scenarios in household structure and by conducting an uncertainty analysis based on the Monte Carlo method. The results indicate that GHG emissions can be reduced by purchasing a new refrigerator, and electricity costs can be reduced by installing LED lamps in the living/dining room. It is also found that there is a wide range of uncertainty for NPV and GHG reductions after replacing a TV because different households watch TV for different lengths of time.

Agrivoltaic systems, comprising photovoltaic panels placed over agricultural crops, have recently gained increasing attention. Emerging interest in these systems led us to investigate their influence on rice crops. Various factors affecting rice crop yield, including fertilizer application, temperature, and solar radiation, were directly observed, and measured to evaluate changes associated with the shading rates of photovoltaic systems installed above rice crops. The results suggest that the allowable upper limit of the shading rate for agrivoltaic installations ranges from 27 to 39%, which sustains at least 80% of the rice yield, a condition set by the Japanese Ministry of Agriculture, Forestry and Fisheries for these systems. If such systems are applied to rice paddies in Japan at 28% density, they could generate 284 million MWh/yr. This is equivalent to approximately 29% of the total Japanese electricity demand, based on 2018 calculations. This projection indicates the potential of agrivoltaic systems for efficient land use and sustainable energy generation.

Which comes first in reducing the Carbon Dioxide (CO2 ) emissions from the transportation sector: consumer preference or technological advancement? Using a series of discrete-choice demand models, we estimate the demand for automobiles in Japan. Our model explicitly allows consumer preferences for fuel economy to evolve over time, and the estimation results confirm the existence of such a change. We then simulate consumer behavior , enabling consumers in 2010 to choose automobiles from 2016, and vice versa. The results imply that both consumer preferences and technological advancement are important—without technological advancement and increases in consumers’ appreciation for fuel-efficient cars, CO 2 emissions cannot be reduced.

Cities accommodate more than half of the world's population and are responsible for most of the global environmental footprints of carbon and resource consumption. Hence, countermeasures to reduce the carbon footprint of cities is critical to confront global and national challenges on climate changes in the “Post Paris Era”. Particularly, carbon emissions arising from the residential sector are of great importance to urban emissions, considering their scale and contribution to the indirect emissions caused by supply chains. Despite much consideration on national or provincial household carbon footprints, there has been little discussion on city-level carbon emissions by source and their correlation with residents-related attributes. Given such a circumstance, the present research explored the indirect household carbon emissions by source and its relationship with potentially affecting attributes through a case study on 49 Japanese prefecture capital-level cities (comprising 47 prefectural capitals and Kitakyushu City and Kawasaki City). We combined data from a national expenditure survey with the Embodied Energy and Emission Intensity Data for Japan Using Input-Output Tables (3EID) to calculate consumption-based carbon footprints. Furthermore, to investigate the correlation between the indirect household carbon footprint (IHCF) and residents-related attributes, we divided IHCF into seven sources (food, accommodation, recreation, education, medical service, energy, and transportation) and analyzed the relation with various attributes. The main results highlight that 1). Spatial unbalanced distribution is observed by IHCF types. 2). Each type of IHCF affected by different socio-economic variables according to stepwise regression analysis result. 3). We found that although total IHCF exhibited a comparatively weak correlation with the selected residents-related attributes, food, transportation, and education separately exhibited significant correlations. The insights obtained in terms of source categories and household-related features of IHCF are expected to provide detailed information for future mitigation policies, i.e., city-level mitigation priority setting.

City-level carbon footprint has been recognized as a useful measure of anthropogenic impact on climate change associated with citizens' activities within the administrative boundary. Although the promotion of consumer responsibility suggests rethinking urban indirect emissions, the detailed methodology is far from satisfactory for realistic applications. Due to the lack of multi-regional input-output tables for most cities, there is a wide application of single regional input-output tables. However, there still lacks further discussion on if there will be an obvious evaluation bias by applying city-level single-regional tables rather than multi-regional ones. To visualize the table coverage on its application consequence, both single- and multi-regional input-output tables were employed to compare disparities in the carbon footprint accounting in the case of Tokyo, Japan. Our analysis shows that the gap of emissions driven by Tokyo's final demand between single- and multi-regional input-output tables was considerably large. Furthermore, the results of multi-regional table were found to be 8.11 MtC higher for coal-generated emissions, 7.83 MtC for crude oil-generated emissions and 2.90 MtC for natural gas-generated emissions than those of the single-regional table. The largest deviation in emissions accounting was observed in the power, gas and heating supply sector, the construction sector and the private service sector. The gap between these two input-output tables was notable for all three types of fossil fuels (coal, crude oil and natural gas). These indicated that coal-generated emissions have been largely ignored by single-regional input-output table. The study highlighted the difference of carbon footprint accounting between these two types of input-output tables. Our findings are intended to assist policymakers and scholars in pinpointing and reallocating sectors that are likely to yield severely biased evaluation of emissions embodied in trade when a multi-regional table is not available.

Since the Great East Japan Earthquake and Fukushima nuclear accident in 2011, both energy consumption and CO2 emissions have been increasing in the residential sector of Japan. For this reason, smart meters have received much attention as a way to provide energy-use feedback to households and thereby encourage energy conservation. In order to provide effective feedback, it is necessary to take into account the lifestyle of each household, but little work has been done to develop a methodology to determine the relationship between a household’s lifestyle and its electricity consumption. This paper proposes two methods that identify a household’s lifestyle from electricity use data. By using a frequency analysis of weekly load profiles, we verified that, except in winter (December 2013–February 2014), the average daily consumption of morning-oriented lifestyles is 5.3% less than that of night-oriented lifestyles. The results of cluster analyses of each household’s daily electric load profiles suggest that most households consume less electricity when following a regular routine.

We investigate whether the contrasting set of transportation policies in Korea---reductions in fuel taxes and increases in diesel automobile prices---has decreased emissions. Using a random-coefficient discrete choice model and hypothetical policy sets, we estimate the automobile demand of consumers, the market share of cars by fuel type, and total emissions, assuming that consumer preferences for driving costs change over time. Then, we separately analyze the effect of each policy set on automobile sales and emissions, particularly carbon dioxide, nitrogen oxide, and particulate matter. Our analyses reveal that Korean consumers have become more sensitive toward fuel costs over time and that the emission consequences of Korean policies depend on consumer preferences.

Given the large accumulation of Greenhouse Gas emissions released by household, individual behaviors play a vital role in decarbonization measurement. Among different residents’ behaviors, using private car is an essential source of household carbon emission. Therefore, deepening the understanding about its variation and determinants is of great importance for decarbonizing individual behaviors. Taking Japan as example, this study firstly evaluates the emissions generated by household private car from 1990 to 2016. Then, by using econometric model, cluster and spatial autocorrelation analysis, both spatiotemporal trend and emissions determinants are given out. Results indicate that although the private car emissions across the whole extent of Japan is declining, depopulation still contributes to increasing emissions in some prefectures. Last, given the future depopulation trend, target-specific decarbonization policy is suggested to take demographic features as the first consideration.

Improving energy efficiency in the residential sector is a pressing issue in Japan. This study examines the economic and environmental impacts of introducing the following distributed energy resources: photovoltaics (PV), a fuel cell, and a battery. We estimate electricity and hot water demand profiles of a household by using simulated living activities. Electric power from a residential PV system is also calculated from the observed solar radiation. By using mixed integer programming, we perform a cost minimization operating simulation of a residential PV, fuel cell, and battery. The result suggests that we can create a net-zero energy house by installing both a PV system and a fuel cell into one house. On the other hand, using a battery with a fuel cell increases the household energy cost, and has few effects on CO2 emission reduction.

While the fuel economy of Japanese automobiles has improved by 40% in the past decade, gasoline consumption in the transportation sector from 2007 to 2016 only decreased by 4%. We seek to explain this discrepancy by investigating Japanese fuel economy standards and the financial incentives given to consumers of fuel-efficient cars. To do so, this study explores whether Japanese policies caused such a rebound effect, by employing the difference-in-difference framework. We find that these policies contribute to energy rebound effect, by enabling higher fuel consumption at lower costs and thus causing higher energy usages. We provide evidence that policies can increase not only fuel usage but also fuel costs. The main driving force behind the rebound effect is the increase in the sales of hybrid vehicles, induced by financial incentives.

Summary Thousands of factories in Japan responded to a survey on power outage costs for industrial customers. From across the country, 5139 facilities designated as energy management factories answered questions about their power consumption and the loss of production value due to a hypothetical hour-long power outage on a summer weekday. Using their responses, we estimated the median unit cost of a power outage across all sectors to be 672 yen/kWh. The service sector of amusement and hobbies and the manufacturing sector that makes electronic information and communication equipment have relatively high unit costs for power outages. The direct cost of damage from a specified power outage across all sectors totaled 77 billion yen. Using input–output analysis, we estimated the indirect damage costs caused by the repercussions of halting production. Indirect damages across all sectors totaled 91 billion yen. The wholesale and retail trade sector had the largest direct damage costs, while the transportation equipment manufacturing sector has the largest indirect damage costs. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 185(4): 25–32, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22306

Using data from a survey, we examined actions taken by large corporations based in three countries to combat climate change and related these actions to the corporations’ financial performance. We analyzed the correlation between financial performance and climate change management performance to determine the extent that climate change management activities are a net cost or a net benefit to companies. We found that corporate climate change management performance is generally positively correlated with financial performance, but that the relationship differs among countries due to national-level external factors. A case study of Japanese automobile manufacturing companies showed that sales of a company’s fuel-efficient cars, reflecting consumers’ awareness of climate change, are associated with higher valuation by financial markets.

The Great East Japan Earthquake devastated the eastern regions of Japan on this March. Due to the nuclear accident caused by the earthquake, Japan’s Cabinet stated to revise energy policies. This article aims at investigating whether we could establish a secure, economical and low-carbon energy system taking account of the serious situation after the Earthquake. For this purpose, we first evaluated possible technology options along with economic options. Then we integrated these options in a computable general equilibrium model for Japan so as to evaluate the impacts to national economy. As results, we quantified the relationships between energy security, quality of life and CO2 emissions.

A survey was conducted on power outage cost for industrial customers. 5139 factories, which are designated energy management factories in Japan, answered their power consumption and the loss of production value due to the power outage in an hour in summer weekday. The median of unit cost of power outage of whole sectors is estimated as 672 yen/kWh. The sector of services for amusement and hobbies and the sector of manufacture of information and communication electronics equipment relatively have higher unit cost of power outage. Direct damage cost from power outage in whole sectors reaches 77 billion yen. Then utilizing input-output analysis, we estimated indirect damage cost that is caused by the repercussion of production halt. Indirect damage cost in whole sectors reaches 91 billion yen. The sector of wholesale and retail trade has the largest direct damage cost. The sector of manufacture of transportation equipment has the largest indirect damage cost.

Japanese government submitted the medium-term target to the secretarial office of Framework Convention on Climate Change that Japan would decrease 25% of greenhouse gases compared with 1990 emissions. This commitment was highly evaluated worldwide. However, some experts criticize that it is impossible to maintain sustainable development under such severe target. This article aims at investigating whether we could realize sustainable development under such ambitious target of reducing greenhouse gas emissions. For this purpose, we first evaluated possible technology options and system innovation along with economic options. Technology options include efficiency improvement, renewable energy technologies and nuclear power technologies. Economic options include carbon tax, emissions trading scheme and feed-in-tariff for renewable energies. Once the promising technologies and policy options were listed up, we integrated these options in a computable general equilibrium model for Japan, which we developed, so as to evaluate the impact to national economy. As results, we identified the condition, how we could realize sustainable development under the 25% target of reducing greenhouse gas emissions.

Recently, energy service providers (ESP) have increased due to deregulation in the power market. They install energy supply equipment at their own cost and supply the necessary energy to the client. The Tokyo Metropolitan Government started Asia's first cap-and-trade program in April 2010. This program caps energy-related carbon dioxide emissions from some 1,330 offices and factories in Tokyo. Then, ESPs have to manage the many risks of energy service project directly linked to the profits. In this paper, we describes the risk analysis and investment optimization for energy service projects using financial engineering.

本論文では，地域間物流が産業活動に伴って発生することを明示的に考慮した物流量の定量化を行う．そのため，産業連関分析の考え方を援用して地域間の物流量を把握する手法を提案する．物流産業連関分析と呼ぶこともできるこの手法では，最終需要によって誘発する物流を対象とする誘導物流と，素材などの生産が最終需要として消費されるまでの物流を捉える派生物流の2種類の物流の把握方法を提示する．前者ではある地域における1単位の最終需要に誘発される地域間の物流量を，後者ではある地域における1単位の生産によって派生する地域間の物流量を定量化するものである．また本論文による地域間流動量の推計値と物流センサスデータによる実績値の整合性を検証し，さらに誘導物流と派生物流について，それぞれ計算事例を示して手法の有用性を確認する．

Greenhouse gas emission from residential sector is difficult to control since emission regulation cannot be implemented to individual household. Government should induce each household to have energy saving lifestyle in order to abate increasing CO2 emissions from household activities. The program to promote the spread of green home appliances by utilizing eco-points has been conducted in Japan since May 2009. Those who have purchased eco-friendly home appliances can apply for the issuance of eco-points and the exchange of issued points for various goods. It is necessary to know consumer preferences for home appliances, so as to verify the effect of CO2 emission reduction of eco-point program. We statistically estimated consumer's utility functions for choosing refrigerators, televisions and air conditioners based on the sales data of them. The utility functions have explanatory valuables such as price, electricity cost, issued eco-points, etc. of individual home appliance. The utility functions enable the simulation of expected effect of CO2 emission reduction under the changing rate of eco-points. While the direct effect of eco-point program was evaluated in this way, we considered the indirect and negative effect on CO2 emissions that derive from the exchange of issued points for goods. Questionnaire survey was conducted for those who have been issued eco-points after purchasing home appliances. As a result, total CO2 emission reduction was estimated as 170 million ton per year by the purchase of green home appliances. In addition, the emission reduction can be expected to increase by approximately 2.4 percent under the revised eco-point program that issues eco-points only to the top 20 percent of efficient home appliances.

The acceleration of diffusion of the DER (distributed energy resources) is hoped for because of the promotion for highly effective use of energy, especially in the house and commercial section in Japan. From this point of view, it is necessary to focus on the feature of DER such as intermittent renewable resources, low quality and low density. The purpose of our study is to clarify the demand of multi (involved low) quality energy and to solve the problem which is optimization of the energy network supply system whose alternative is DER system and large power grid. For these reasons, in this paper, we drew up and sent out questionnaires and analyzed them by CVM. After we evaluated the potential of the multi-quality energy supplying system, we concluded that low energy quality have enough possibility to supply for some of the home appliance.

温室効果ガスの排出量が増加している業務部門においては，地球温暖化対策のひとつとして，ガスコージェネレーションが有効である．一方，電力の自由化に伴い，欧米では先例があるものの，わが国では新しい事業形態として，エネルギーサービスプロバイダが設備の所有者となって，需要家にエネルギーサービスを提供する事業が2000年前半に登場した．そのため，エネルギーサービスを行う事業者は，収益性に直結するより多くの事業リスクを管理していく必要がある．本研究では，事務所ビル，シティホテル，病院を対象としたガスコージェネレーションのエネルギーサービス事業を対象に，ファイナンシャルリスクの分析を行い，各種リスクへの対応策およびその効果を評価した．

Global warming has been recognized as a serious issue since the fourth assessment report of the Intergovernmental Panel on Climate Change was published in 2007. Under these circumstances, Clean Development Mechanism (CDM) is expected to play a significant role, since it promises to reduce the economic gaps between developed and developing nations, as well as to economically reduce greenhouse gas emissions. In this paper, we first investigate how to evaluate risks in CDM. The real option theory is applied to quantify project risks in CDM, so that we can estimate the option values. In detail, a mathematical model of CDM is represented with a compound rainbow option, which includes continuous procedures from registration to investment. The evaluated results identify the condition of profitability, in which investment as CDM project is feasible. Our evaluation also quantifies how CDM projects become difficult to be executed due to the registration risk and the post-2012 risk. Then we investigate how to activate CDM projects. For this purpose, two options are considered: low interest loans by official financial institutions and the procurement of certified emission reductions, (CERs) by governments. The former relates to the low interest loans similar to environmental official development assistance (ODA), which certainly ease the financial burden of initial investments in CDM projects. Now that CDM projects related to ODA are already registered by CDM executive board, this option is worth evaluation. The latter, meanwhile, aims at lowering risks by the secure purchase of CERs by governments. Since the governments of the Netherlands and Japan have already established a system to purchase CERs generated by CDM, we need to assess the effect of the option to activate CDM. Based on actual financial data on CDM, we finally investigate how these options could increase the number of executable CDM projects.

Achievement of CO2 emission reductions in the automobile sector is a complex problem because of the difficulties in regulating consumer behavior. The approach of the present study is not government regulation of consumer CO2 emissions but the encouragement of responsible environmental behavior using the bounded rationality of consumers based on behavioral economics. Currently, greenhouse gas (GHG) emission credits are mainly traded among corporations. However, the use of small-lot emission credits is expected to begin spreading to consumers. We propose a system through which small-lot emission credits can be purchased by the consumers during the purchase or renewal of automobile insurance. Drivers can offset vehicle CO2 emissions by purchasing emission credits. In the present study, we analyzed the market potential for small-lot GHG emission credits attached to automobile insurance. A consumer survey of 351 drivers was conducted in Japan. Consumer preferences are evaluated using conjoint analysis and the contingent valuation method (CVM). The average value of the marginal willingness to pay (WTP) for GHG emission credits is estimated to be approximately 2171 yen per ton-CO2. The median WTP for GHG emission credits is estimated to be approximately 2260 yen per year. Assuming that the average driver in Japan travels a distance of 10,000 kilometers per year and the vehicle fuel efficiency is 10 kilometers per liter, the WTP for GHG emission credits corresponds to approximately 30 percent of each driver's CO2 emissions.

The clean development mechanism (CDM) is attracting increased attention because it is a promising method for economic reduction of greenhouse gas emissions and is expected to reduce the economic gaps between developed and developing nations. We investigated how to quantify and manage risks in CDM from the viewpoint of the investor. Real option theory was applied to quantify project risks in CDM so that we could quantitatively compute the option values. A mathematical model of CDM was represented with a compound rainbow option, which included continuous procedures from registration to investment. The evaluated results identified the condition of profitability in which investment as CDM is feasible. Our evaluation quantified how CDM projects become difficult to execute due to registration risk and post-2012 risk. In particular, registration risk was shown to make stronger adverse impact on CDM than post-2012 risk. We also investigated the effect of procuring certified emission reduction (CER) by government. Based on actual financial data on CDM, we investigated how the risks and the procurement influence the number of executable CDM projects. Quantitative estimation was made on the effect of reducing risk by our real option analysis and the number of feasible CDM projects was evaluated using the actual data.

Due to the rapid increase of CO2 emissions in the household sector, many simulations have been conducted for the yearly CO2 emissions in a house assuming the characteristics of energy supply system. However, there is no standard for the behaviors in the household sector. We focus on the variation of personal pattern of life and estimate load curves of the houses based on the data of average and variance of the behaviors. Then, we simulate the yearly CO2 emissions for the different regions, energy supply systems, insulation, number of persons per household, and renewable energy. Cogeneration system has more variance between households than between regions. As for the additional solar water heater, there is the effect of large offset for the gas-engine cogeneration following the heat load, and small offset for the fossil fuel of high efficiency of power generation. Utilizing the simulation results for more than 200 households, we make the regression model which explains the yearly CO2 emissions by the temperature, ratio of total load (electricity/heat), number of person per household, and insulation. It is indicated that cogeneration system helps CO2 emission reduction for cold region and low insulation houses.

In this study, we investigate an inter-industrial and inter-regional recycling system for industrial waste by the cement industry in Japan. We develop a linear programming model that represents cement production processes and waste transportation of all cement factories in Japan. We simulate cost and CO 2 -minimizing systems. The result implies that making waste transportation more efficient in cost is an effective means for CO 2 reduction.

This study focuses on animal and plant residue, which is generated from the baking factory, and proposes the efficient use of the organic waste by the anaerobic digestion.The energy recovery system uses generated methane gas from the baking factory. We evaluate the feasibility of the system by considering the economical efficiency and CO2 emission reduction potential.As a result of proof test, 472Nm3 of biogas was obtained from a ton of the normal residue of baking factory. The methane density in the generated biogas was 64%. As for the usage of the biogas, we examined three cases: boilers to heat, generators to electricity, and co-generation to heat and electricity. Then, three cases are compared with the incineration of the residue from the viewpoint of CO2 emission reduction and economical efficiency.It was found that the largest CO2 emission reduction was given by the co-generation system while the lowest cost was given by the boiler heating system.Assuming that this system is subsidized by the Ministry of Agriculture, Forestry and Fisheries, half of the initial cost can be endowed. Then, the internal rate of return becomes 22.4 % in the case of the boiler heating system. This result indicates the boiler heating system is economically efficient from the usual investment standard. The co-generation system is also feasible under the subsidy since the internal rate of return of the co-generation system even reaches 13.0 %.

As the first commitment period of Kyoto protocol comes nearer, Clean Development Mechanism (CDM) attracts more and more attention to economically reduce greenhouse gas emissions. In this paper, we investigated how to quantify and to manage risks in CDM. Since management of project risks is crux of this paper, real option theory is applied to evaluate CDM projects, so that we could quantitatively compute the option values. Namely, a mathematical model of CDM was represented with a compound rainbow option, which includes continuous procedures from registration to investment. The evaluated results identified the condition of profitability, in which investment as CDM are feasible. Our evaluation also quantified how the execution of CDM became difficult by the registration risk and the post-2012 risk. Then we investigated the effect of CER procurement by government. Based on actual financial data on CDM, we finally investigated how the risks and the governmental policy influence the number of executable CDM.

In this paper, we consider the investment risk of nuclear power plants using the real options approach. It is essential that the Japanese society evaluate the investment risk, because nuclear power plants are facing definite uncertainty and Japanese governments intend to promote and assist nuclear power plants through subsidies and policy actions.We assumed that the wholesale market prices of electricity constitute the definite uncertainty and that the wholesale market prices follow the geometric Brownian motion with drift. Using the Bellman equation and a lattice framework, we evaluated the value of investment opportunity, the value of equipment, and the critical prices that are optimal prices to invest in a nuclear power plant in the finite time horizon.This analysis shows that higher volatility of the wholesale market prices would give power companies lower incentive to construct electric power plants, particularly capital-intensive power plants. In order to deliberate and hold the Japanese governments accountable for the economics of nuclear power plants, multifaceted evaluation is needed.

While at present mostly recycled into road subbase, the amount of demolished concrete in Japan is expected to increase rapidly and exceed the demand for road subbase in the near future. To promote the recycling of concrete, a technology to produce high-quality recycled aggregate has been developed. This technology employs the heating and rubbing method. In order to investigate a future concrete recycling system, first of all, a specific model considering indices of economic activity is established to forecast the amount of demolished concrete in the future. Furthermore, an input-output table is extended by a detailed description of concrete-related industries such as construction, aggregate, cement, and ready-mixed concrete, and several concrete recycling processes have been added. The linear programming model connected to the input-output table assumes that the technology will be introduced in 2020. A subsidy for high-quality recycled aggregate and a carbon tax are found to be effective ways to promote the early introduction of the technology. This series of analysis can be widely used in other countries for investigating suitable recycling systems focusing on the cement and concrete industry as well as the applicability of each individual concrete recycling technology.

Clean development mechanism (CDM) is expected to facilitate technology transfer from developed to developing countries as well as to economically reduce greenhouse gas emissions. In this article, we explore effective institutions to activate CDM projects. For this purpose, we have estimated internal rate of return (IRR) and other indicators on profitability for 42 CDM or JI projects, taking account of volatilities in the price of certified emission reductions (CER). As a result of Monte Carlo simulations, expected values and standard deviations in the IRR of the projects were quantitatively shown. Then we evaluated various risks in CDM, concluding that diversification of investment is an effective way to suppress these risks. Therefore securitization of CDM finance is proposed as a means of facilitating the diversification of investment. Namely, we present the concept of a CDM bond, which is a project bond with CER. We also investigated the role of governments to suppress risks in CDM. Referring to CERUPT, initiated by the Netherlands’ government, the institution of “insured CERUPT” is proposed to suppress downside risks in the IRR of the projects. We concluded that it is possible to make CDM projects viable by the “insured CERUPT” and CDM bond.