12.4 Conclusions
This study developed an integrated evaluation system for CO 2 emissions under
(i) land-use scenarios considering both climate change mitigation and adaptation
and (ii) technological mitigation scenarios considering the introduction of PVs and
EVs. The land-use scenarios built by using a spatially explicit land-use model
which had been based on real estate data, were applied for the case study of this
evaluation system. Our CO 2 emission estimation model could estimate not only
direct emissions but also indirect emissions based on household expenditure. As a
case study, we showed the future spatial distribution of CO 2 emissions by using this
integrated evaluation system.
This evaluation system could be used as a decision support system for the
evaluation of CO 2 emissions under land-use scenarios considering climate mitigation and flood risk adaptation for resilient cities. Urban and regional planners might
implement economically-based planning of urban improvement projects, spatial
distribution of population density, public transportation projects and energy saving
of households. They could also select retreat and cohesion areas considering
compact city design and disaster prevention on the neighborhood scale. A different
diffusion rate of PVs and EVs in each zone could be set as scenarios. Policy-makers
could compare each effect on CO 2 emission reduction.
The results of this case study suggest that climate change mitigation and
adaptation can generate both a synergistic and trade-off effect from the viewpoint
of CO 2 emissions. We have to find a strategy for compatibility between mitigation
and adaptation using an evaluation system like the one in this study.
The results suggest that the compactness of land use and the introduction of PV
panels installed on detached houses are not compatible from the viewpoint of CO 2
emission reduction because more compactness means fewer detached houses. In the
future, we should consider scenarios assuming the installation of PV panels on the
top of apartment/office buildings in the city center or around stations, and
the introduction of mega solar power plants in suburban areas where people
retreated. We postpone these considerations to future research. It is necessary to
consider the interchange of surplus electricity generated by PVs. The electric power
interchange among household types with different living hours should also be
considered, as pointed out by Taniguchi and Ochiai (2012). In this study, the
indirect emissions were estimated per year. The variations in time for both PV
supply and household demand must be considered as pointed out by Esteban
et al. (2012). The emissions were related to energy and gasoline change by
scenarios. Emissions from other sources should be considered from the viewpoint
of Life Cycle Assessment. Also, the cost for realizing land-use scenarios such as
people’s move should be calculated and compared with the cost of infrastructure for
flood disaster prevention such as levee and padding based on cost-benefit analysis.
The dispersed city has the potential of making services inefficient in the city and of
increasing the cost for infrastructure. Because the compact city may be economical
and efficient in consideration of CO 2 emissions by logistics, further studies are
12 An Integrated Model for Assessing Carbon Dioxide Emissions Considering. . .
259
This study developed an integrated evaluation system for CO 2 emissions under
(i) land-use scenarios considering both climate change mitigation and adaptation
and (ii) technological mitigation scenarios considering the introduction of PVs and
EVs. The land-use scenarios built by using a spatially explicit land-use model
which had been based on real estate data, were applied for the case study of this
evaluation system. Our CO 2 emission estimation model could estimate not only
direct emissions but also indirect emissions based on household expenditure. As a
case study, we showed the future spatial distribution of CO 2 emissions by using this
integrated evaluation system.
This evaluation system could be used as a decision support system for the
evaluation of CO 2 emissions under land-use scenarios considering climate mitigation and flood risk adaptation for resilient cities. Urban and regional planners might
implement economically-based planning of urban improvement projects, spatial
distribution of population density, public transportation projects and energy saving
of households. They could also select retreat and cohesion areas considering
compact city design and disaster prevention on the neighborhood scale. A different
diffusion rate of PVs and EVs in each zone could be set as scenarios. Policy-makers
could compare each effect on CO 2 emission reduction.
The results of this case study suggest that climate change mitigation and
adaptation can generate both a synergistic and trade-off effect from the viewpoint
of CO 2 emissions. We have to find a strategy for compatibility between mitigation
and adaptation using an evaluation system like the one in this study.
The results suggest that the compactness of land use and the introduction of PV
panels installed on detached houses are not compatible from the viewpoint of CO 2
emission reduction because more compactness means fewer detached houses. In the
future, we should consider scenarios assuming the installation of PV panels on the
top of apartment/office buildings in the city center or around stations, and
the introduction of mega solar power plants in suburban areas where people
retreated. We postpone these considerations to future research. It is necessary to
consider the interchange of surplus electricity generated by PVs. The electric power
interchange among household types with different living hours should also be
considered, as pointed out by Taniguchi and Ochiai (2012). In this study, the
indirect emissions were estimated per year. The variations in time for both PV
supply and household demand must be considered as pointed out by Esteban
et al. (2012). The emissions were related to energy and gasoline change by
scenarios. Emissions from other sources should be considered from the viewpoint
of Life Cycle Assessment. Also, the cost for realizing land-use scenarios such as
people’s move should be calculated and compared with the cost of infrastructure for
flood disaster prevention such as levee and padding based on cost-benefit analysis.
The dispersed city has the potential of making services inefficient in the city and of
increasing the cost for infrastructure. Because the compact city may be economical
and efficient in consideration of CO 2 emissions by logistics, further studies are
12 An Integrated Model for Assessing Carbon Dioxide Emissions Considering. . .
259