An extended application of the concept of material flow cost accounting (MFCA) was studied to improve operations of industrial wastewater treatment. A soft-drink factory was chosen as a study field, which has two series of wastewater treatment processes running in parallel; one is anaerobic treatment featuring energy-saving, and the other is aerobic moving bed, relatively tolerant to load fluctuations. For optimizing daily load distribution to each series, we created a novel “MFCA failure risk evaluation model” which enabled analysis on failure risks and other operational costs in one flowsheet. An optimal value of daily increase limit of BOD loading to the anaerobic series was obtained, which gave minimum sum of the failure risk and energy consumption. Simulation results based on the actual loading data revealed that the estimated failure risk could be reduced from 52,000 yen·d⁻¹ to 50,000 yen·d⁻¹ by applying this optimal BOD limit control. Furthermore, reductions in power consumption and sludge disposal costs could be predicted, resulting in the total operating cost reduction by 29,000 yen·d⁻¹ (11％). It was concluded that the MFCA failure risk evaluation model can comprehensively improve operational costs besides failure risk, showing the significance of its continuous practice.

While international economic activities have profound impacts on the environment, there are no consolidated initiatives to environmental considerations in such activities thus far. The focus of this article is the development assistance. This article, taking up the revision processes of the Guidelines for Environment and Social Considerations established by the Japan International Cooperation Agency (JICA) as a case, aims to identify key points of discussion in the revision processes, after delineating and analyzing the processes and the main contents of the revision. The key points of discussion in the revision processes were identified to be the following three points: information disclosure, responses to climate change, and protection of natural habitats. In the future, it is necessary to consider the introduction of comprehensive initiatives that are common to all international economic activities, not only for development assistance but also for trade and investment, in environmental considerations.

This study discussed the reliability of the reported release and transfer of chemical substances under the Japanese Pollutant Release and Transfer Register (PRTR) in terms of the estimation techniques. Our questionnaire surveys to PRTR-reporting facilities revealed the following. The releases/transfer to public water bodies, soil, on-site landfill, and sewage treatment were reported as zero in most cases due to that no releases/transfers were expected at the facilities. Regarding the release to air and the transfer to waste treatment, in half the cases where the reported data estimated based on mass balance (10％ of the total reported data), the reported releases/transfers occupies less than 0.01 of the production/use amounts, suggesting that these data may deviate from the actual amount by one order of magnitude. Half of the reported data estimated using direct monitoring (5％ of the total reported data) were not sufficiently reliable because they were based on annual or biannual measurements, even though the emission concentration variations were unknown. Approximately 30–40％ of the reported data estimated using emission factors (10％ of the total reported data) were based on the factors from literature or unknown sources. The reliability of these releases/transfers depends on the applicability of the factor to individual facility.

Measures targeting the achievement of a decarbonized society in local areas are expanding. To examine measures at the local scale and also develop them for social implementation, it is important to value the perspectives of the public, to create scenarios for achievement based on the characteristics of local areas, and to ensure that the public recognizes them as common issues. This study responded to these challenges and attempted to create a scenario aimed at realizing net zero CO₂ emissions from energy in Shiga Prefecture in 2050. A qualitative description of future society was generated based on opinions from the perspectives of the public cited in actual scenes of policymaking. Based on this, a quantitative description of society was generated by inputting the established conditions as parameters in a mathematical model for estimating the local socioeconomic structure and CO₂ emissions. This method made it possible to link net zero CO₂ emissions, which is not a target of keen interest to the public, to everyday lifestyle, local challenges, and other familiar concerns from the perspectives of the public. In addition, it demonstrated the possibility of increasing the public’s recognition of created scenarios as common issues by quantitatively showing the benefits to the local area.

In this study, we developed an analysis method for texts obtained through qualitative research such as interviews, and workshops conducted by administrative agencies in Shiga Prefecture to structurally understand climate change impact perceptions.

In this study, text mining methods were applied to text data obtained from a qualitative survey of citizens, agriculture, forestry, fishery, industry, and business entities in Shiga Prefecture. As a result, we were able to identify five topics: “typhoon damage, animal damage, and paddy rice damage”, “seasonal changes”, “summer and winter effects of rising temperatures”, “rainfall and snowfall extremes and their effects on disasters and forestry”, and “Lake Biwa and natural ecosystem effects”. The cross-tabulation results show that citizens mentioned a wide range of sectors, while stakeholders in agriculture, forestry, and fisheries provided detailed information on climate change impacts in relevant sectors. It was found that combining the texts of the relevant actors makes it possible to understand the climate change impacts that are becoming apparent in the region in some detail.

In this study, an online questionnaire survey was administered to understand the current situation of people’s perceptions and attitudes toward risks related to climate change and their efforts to take countermeasures and obtain suggestions for promoting countermeasures in future.

Note that 73.8％ of respondents believe that global warming is primarily caused by human activities. Moreover, many respondents think that it is an issue that transcends generations, countries, and regions and that it is necessary to take measures to prevent its impact.

In terms of countermeasures, the implementation rate of energy saving (64.0％) and heat stroke prevention (57.5％) is high. The number of mitigation countermeasures implemented was higher than adaptation. Furthermore, comparing the number of actions implemented by classifying countermeasure actions into mitigation and adaptation, the number of actions implemented by mitigation measures was higher. Because of multiple regression analysis to clarify the factors that determine the number of measures to be considered, people recognize global warming as a problem to be addressed and implement mitigation measures. However, adaptation measures may be implemented not as a measure to the global warming problem but as a response to individual impact.