COVID-19 is still running rampant throughout the world, and even after a vaccine becomes widely available, our human society will need to coexist with it for the foreseeable future. In order to plan any policies for mutuality, it is necessary to understand the various measures currently being implemented as well as the changes in people's lifestyle behavior in response to these measures. However, the impacts of each measure for COVID-19 on our lifestyle behavior have not been clarified. This study analyzed travel behavior during COVID-19 in several countries which have different intensities of implementing the measures (Japan, Taiwan, Thailand, India, and Italy) to clarify the measures and other factors that influenced changes in travel behavior. Additionally, the change in travel behavior has also affected the environmental aspect. Hence, the air pollution (PM2.5) during the pandemic was analyzed and clarified. As a result, it was revealed that travel behavior plummets drastically in countries that implement high-intensity measures such as lockdown and curfews than in the countries in which low-intensity measures were applied. It was also found that after high-intensity measures were terminated, the rate of going out around the train station decreased by 10 to 20%. Conversely, the impact of changes in travel behaviors on air pollution PM 2.5 was not as significant.

In Japan, it lays emphasis on the need for local action in order to achieve the SDGs, but less than half of the municipalities are taking those actions in 2020. The paper presents a method that will enable policy makers to understand the degree of achievement of local government SDGs. The proposed method was applied to evaluate 43 local governments in Osaka prefecture. As a result, it was shown that the entire local governments in Osaka prefecture in particular should work on strengthening the target in the environmental field.

The centralized wastewater treatment system (CWWT) resulted by economies of scale plays an essential role in improving urban environment and saving water resources, but it needs the support of a complicated pipeline system due to usually location far from the city center. The decentralized wastewater treatment system (DWWT) is another option for treating wastewater and reusing effluent on site, with an advantage of not requiring a pipeline system. This study evaluated a large community-based wastewater treatment system comparing operating in DWWT or CWWT. The results show that: 1) CWWT consumes only 20% of the electricity of DWWT in its operation phase, but consumes 14 times more chemicals and 158 times more fresh water than DWWT; 2) pipeline system supporting CWWT contributes 65% of total GHG emissions during the construction phase; and 3) the critical distance is 56 km when applying 300 mm internal diameter reinforced concrete pipes (RCP), and is shortened in scenarios where thicker RCPs are used and replaced with prestressed concrete cylinder pipes.

After the Great East Japan Earthquake, nuclear power plant use decreased, and renewable energy use increased. Besides, the number of households using solar power is expanding rapidly. However, the FIT (Feed-in Tariff) ended in 2019, and the purchase price of surplus electricity purchased by the electric power companies dropped significantly from 48 JPY/kWh to 7 JPY/kWh. Hence, it has expected that it will be complicated to recover a cost. Therefore, by storing the surplus power of the solar panel (PV) in the storage battery (BT) installed in the electric vehicle (EV), the spread of PV, which is an unstable power source, is expanded, and the demand and supply of grid power increased. Also, a so-called V2H (vehicle to home) method in use as a power supply and demand adjustment system for grid power. In this research, the authors estimated the effect of reducing the system power consumption of a house by V2H using automatic life schedule generation software “SCHEDULE ver2.0” developed by the Society of Air Conditioning. Accurately, the authors calculated the reduction in annual grid power consumption for housing in Kitakyushu by considering the hourly power demand, the amount of PV power generation, and the hourly patterns in which EVs stop at homes. As a result, comparing households with V2H and households with PV and EV but not V2H, the annual grid power demand of households with V2H is about 12% lower, which is annual. CO2 emissions were as low as 12%.

Fukuoka Prefecture, Japan, has been heavily affected by COVID-19. Since the first patient reported in February 2020, the total case count has risen to 34,937 as of June 12, 2021. However, the effects of these conditions on industrial plastic waste (IPW) collection and their implications for future trends in this area are still not clear. This study statistically analyzed monthly collection trends and geographic variations in the total amount of IPW collected in Fukuoka Prefecture based on daily waste manifest data from a local company. We found the total amount of IPW collected decreased significantly in April and May 2020 corresponding to a state of emergency. Meanwhile, a fact was confirmed that not all facilities were affected by it. Furthermore, multiple linear regression analysis confirmed that the amount of IPW collected monthly from the wholesale and retail trade sector was strongly correlated (R² = 0.94) with both the amount of sales in that sector and the number of patients with COVID-19. Finally, we developed a machine learning approach to future prediction with regard to the amount of IPW to be collected from individual facilities. We confirmed that future predictions made by machine learning had higher accuracy (93.6%) than those made using a statistical approach (83.1%). This study demonstrates that waste manifest data are useful not only for illuminating trends in IPW collection but also for making future predictions regarding the amount of IPW to be collected.

It is expected that the environmental load will be reduced as one of the social effects of telework. However, the rebound effect of carrying out other activities due to the unnecessity of commuting also generates. This study developed a method to estimate changes in CO2 emissions between rural migration due to telework and conventional lifestyles (living and commuting in metropolitan area) using behavioral data of people who work in rural area due to telework. By making a trial calculation using this method and performing a sensitivity analysis, we confirmed the factors that affect CO2 emissions. As a result，it was estimated that rural migration due to telework increases CO2 emissions by fourfold compared to the conventional lifestyles, mainly contributed by energy consumption of home increase. However, the results also suggested that it is possible to reduce energy consumption by around half. Regarding the rebound effect of rural migration due to telework, CO2 emissions will increase due to both the increase in travel time except commuting and using automobile. However, in many cases, the energy consumption of home or office far exceeded the rebound effect. These results indicated that the low-carbonization of rural migration due to telework can be significantly facilitated through appropriate energy use.

With climate change, disasters will change not only in scale, but also in phenomena such as complex disasters. The risk of simultaneous flooding and storm surge is assessed for Urado Bay in the Kochi Plain using 5km grid dynamical downscaling climate change projection datset. Large-scale flooding occurs when typhoons passing west of Kochi City or outside the region send water vapor into the mountains, while storm surges occur when typhoons pass directly through the area. Currently, it is empirically believed that large-scale floods and storm surges do not occur simultaneously. In the future with a 4-degree temperature increase, there will be risk of complex disaster events. This may be due to the increased strength of the typhoon, which will affect the city even when it is passing through the west side of Shikoku island.

To secure the mobility need for individual door-to-door service in depopulated areas with dispersed population, taxi subsidy scheme for elderly is being implemented by many local authorities． However, during the implementing process, many issues relating to this policy such as subsidy amount, number of usage time & distributed ticket, settings for target person and target area are appearing. Based on this awareness, in this study, we will illustrate the taxi subsidy scheme by three sites: local government who support the policy with subsidy; small and medium sized taxi operators with TSS influence on business management; and elderly people with their outing status and TSS usage status. Furthermore, based on the trends of national policies, we examined the effective usage of taxi subsidy scheme as a mobility for elderly people in rural areas.

This study examined changes in how citizens are involved in environmental conservation and natural resource management, focusing on the oriental white stork’s current reintroduction and the associated reconstruction of “co-inhabitance with nature.” By distinguishing between subjects and targets of activities, the study revealed changes in “overemphasis on storks” and the “active/passive co-inhabitance society with storks.” From the time of the storks’ initial release to the present, there have been various problems associated with their reintroduction. Therefore, in order to succeed in reintroducing the storks into the wild and to expand the citizen network, environmental education and community education are necessary to foster the ability and attitude to proactively engage in environmental issues and conservation.

The purpose of this study is to establish a process guideline for the realization of the development and operation of public spaces that contribute to the formation of sustainable communities. In particular, we aim to build guidelines that contribute to the direction in which administrative staff have a producer-like perspective on the creation of public works projects based on overall optimization in the region. As a research method, we conducted a previous research survey and verified the case of the Ogal Project in Shiwa Town, Iwate Prefecture, which is a public project through public-private partnership, and extracted the viewpoints necessary for project execution. Furthermore, focusing on the three factors that mean the quality of publicity, we confirmed the validity of creating "common value" based on the balance between social value, environmental value, and economic value, and based on these results, established "Process Guidelines for Creating sustainable public works". After that, we conducted hearing surveys, etc. with local government officials to verify their validity.

Japanese bioenergy production system is strongly connected to the use of biomass from the country’s extensive forest resources and forest industry residues. Kiso town is promoting the use of woody biomass as a source of heat. However, if the younger generation is not aware of this project or biomass itself, there may be a shortage of future personnel in the biomass industry. Therefore, the education of woody biomass for the younger generation in Kiso Town might help regional revitalization. This study explores primary school students’ perceptions of biomass energy from forests with several factors.