Yasuaki Hijioka - Academia.edu (original) (raw)

Papers by Yasuaki Hijioka

Key observed and projected climate change impacts are summarized in Tables 24-1, SM24-4, and SM24... more Key observed and projected climate change impacts are summarized in Tables 24-1, SM24-4, and SM24-5 (based on Sections 24.4.1-6).

There are concerns about the impact of climate change on Olympic Games, especially endurance even... more There are concerns about the impact of climate change on Olympic Games, especially endurance events, such as marathons. In recent competitions, many marathon runners dropped out of their races due to extreme heat, and it is expected that more areas will be unable to host the Olympic Games due to climate change. Here, we show the feasibility of the Olympic marathon considering the variations in climate factors, socioeconomic conditions, and adaptation measures. The number of current possible host cities will decline by up to 24% worldwide by the late 21st century. Dozens of emerging cities, especially in Asia, will not be capable of hosting the marathon under the highest emission scenario. Moving the marathon from August to October and holding the games in multiple cities in the country are effective measures, and they should be considered if we are to maintain the regional diversity of the games.

Nature Communications, 2020

More than half of the world’s population currently live in urban areas and are particularly at ri... more More than half of the world’s population currently live in urban areas and are particularly at risk from the combined effects of the urban heat island phenomenon and heat increases due to climate change. Here, by using remotely sensed surface temperature data and social-ecological indicators, focusing on the hot dry season, and applying the risk framework of the Intergovernmental Panel on Climate Change, we assessed the current heat health risk in 139 Philippine cities, which account for about 40% of the country’s total population. The cities at high or very high risk are found in Metro Manila, where levels of heat hazard and exposure are high. The most vulnerable cities are, however, found mainly outside the national capital region, where sensitivity is higher and capacity to cope and adapt is lower. Cities with high levels of heat vulnerability and exposure must be prioritized for adaptation. Our results will contribute to risk profiling in the Philippines and to the understanding...

Environment International, 2020

Climate change mitigation efforts to reduce greenhouse gas (GHG) emissions have associated costs,... more Climate change mitigation efforts to reduce greenhouse gas (GHG) emissions have associated costs, but there are also potential benefits from improved air quality, such as public health improvements and the associated cost savings. A multidisciplinary modeling approach can better assess the co-benefits from climate mitigation for human health and provide a justifiable basis for establishment of adequate climate change mitigation policies and public health actions. An integrated research framework was adopted by combining a computable general equilibrium model, an air quality model, and a health impact assessment model, to explore the long-term economic impacts of climate change mitigation in South Korea through 2050. Mitigation costs were further compared with health-related economic benefits under different socioeconomic and climate change mitigation scenarios. Achieving ambitious targets (i.e., stabilization of the radiative forcing level at 3.4 W/m 2) would cost 1.3-8.5 billion USD in 2050, depending on varying carbon prices from different integrated assessment models. By contrast, achieving these same targets would reduce costs by 23 billion USD from the valuation of avoided premature mortality, 0.14 billion USD from health expenditures, and 0.38 billion USD from reduced lost work hours, demonstrating that health benefits alone noticeably offset the costs of cutting GHG emissions in South Korea.

Japanese Journal of Environmental Education, 2016

Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research), 2017

Japanese Journal of Environmental Education, 2017

Frontiers in Energy, 2018

Waste management is becoming a crucial issue in modern society owing to rapid urbanization and th... more Waste management is becoming a crucial issue in modern society owing to rapid urbanization and the increasing generation of municipal solid waste (MSW). This paper evaluates the carbon footprint of the waste management sector to identify direct and indirect carbon emissions, waste recycling carbon emission using a hybrid life cycle assessment and input-output analysis. China and Japan was selected as case study areas to highlight the effects of different industries on waste management. The results show that the life cycle carbon footprints for waste treatment are 59.01 million tons in China and 7.01 million tons in Japan. The gap between these footprints is caused by the different waste management systems and treatment processes used in the two countries. For indirect carbon footprints, China's material carbon footprint and depreciation carbon footprint are much higher than those of Japan, whereas the purchased electricity and heat carbon footprint in China is half that of Japan. China and Japan have similar direct energy consumption carbon footprints. However, CO 2 emissions from MSW treatment processes in China (46.46 million tons) is significantly higher than that in Japan (2.72 million tons). The corresponding effects of waste recycling on CO 2 emission reductions are considerable, up to 181.37 million tons for China and 96.76 million tons for Japan. Besides, measures were further proposed for optimizing waste management systems in the two countries. In addition, it is argued that the advanced experience that developed countries have in waste management issues can provide scientific support for waste treatment in developing countries such as China.

Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research), 2015

Environmental Research Letters, 2017

Dependence of economic impacts of climate change on anthropogenically directed pathways Jun'ya Ta... more Dependence of economic impacts of climate change on anthropogenically directed pathways Jun'ya Takakura et al-An Occupational Heat-Health Warning System for Europe: The HEAT-SHIELD Platform Marco Morabito et al-Estimation of work-related injury and economic burden attributable to heat stress in Guangzhou, China Rui Ma et al

Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research), 2012

Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research), 2012

Environmental Economics and Policy Studies, 2006

We have been developing a policy support tool, AIM/impact[policy], for use in the integrated asse... more We have been developing a policy support tool, AIM/impact[policy], for use in the integrated assessment of global warming control targets including the stabilization of greenhouse gas concentrations, economically efficient emissions paths to realizing these targets, and consequent impacts and risks of these targets. In this study, a quantitative assessment was made of climate changes and global warming impacts, as well as the timing of greenhouse gas reduction policies, under greenhouse gas stabilization constraints. An energy economic model estimating the optimal emissions path for greenhouse gases and an impact assessment model estimating the impacts of global warming in various fields caused by climate changes under this optimal emissions path were used in our assessment. In contrast to the business-as-usual case, our results showed that in order to maintain greenhouse gas concentrations at less than 500ppm (by volume), reduction volumes must be 3.0GtCeq/year by 2020 and 12.2 GtCeq/year by 2050, indicating an urgent need for a full-scale reduction system.

Environmental Research Letters, 2017

We performed an intercomparison of river discharge regulated by dams under four meteorological fo... more We performed an intercomparison of river discharge regulated by dams under four meteorological forcings among five global hydrological models for a historical period by simulation. This is the first global multimodel intercomparison study on dam-regulated river flow. Although the simulations were conducted globally, the Missouri-Mississippi and Green-Colorado Rivers were chosen as case-study sites in this study. The hydrological models incorporate generic schemes of dam operation, not specific to a certain dam. We examined river discharge on a longitudinal section of river channels to investigate the effects of dams on simulated discharge, especially at the seasonal time scale. We found that the magnitude of dam regulation differed considerably among the hydrological models. The difference was attributable not only to dam operation schemes but also to the magnitude of simulated river discharge flowing into dams. That is, although a similar algorithm of dam operation schemes was incorporated in different hydrological models, the magnitude of dam regulation substantially differed among the models. Intermodel discrepancies tended to decrease toward the lower reaches of these river basins, which means model dependence is less significant toward lower reaches. These case-study results imply that, intermodel comparisons of river discharge should be made at different locations along the river's course to critically examine the performance of hydrological models because the performance can vary with the locations.

Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research), 2014

Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering), 2013

Proceedings of the Symposium on Global Environment, 2008

Future long-terrn changes in global water resources driven by socioeconomic and climatic changes,... more Future long-terrn changes in global water resources driven by socioeconomic and climatic changes, Hydrolog.

Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering), 2011

2 正会員 博士(工学) 国立環境研究所 研究員(〒305-8506 つくば市小野川16-2) 3 正会員 博士(工学) 国立環境研究所 主任研究員(〒305-8506 つくば市小野川16-2)... more 2 正会員 博士(工学) 国立環境研究所 研究員(〒305-8506 つくば市小野川16-2) 3 正会員 博士(工学) 国立環境研究所 主任研究員(〒305-8506 つくば市小野川16-2) 4 正会員 博士(工学) 国立環境研究所 主任研究員(〒305-8506 つくば市小野川16-2) Several reports have assessed water scarcity globally using a widely accepted index on an annual basis, namely, withdrawal-to-water resources ratio (WWR). Here, we ask whether it is appropriate to use the WWR to assess the impact of climate change. Global warming is projected to increase the temporal and spatial variability of precipitation, decrease snowfall, and change the timing of snowmelt. To assess the impact of climate change on global water resources incorporating sub-annual timescale phenomena, this study applies a new water scarcity index on a daily basis termed the cumulative withdrawal-todemand ratio (CWD). Our results indicated that global warming increased the mean annual runoff in 61% of the total land area globally. However, in 22% of the area where runoff increased, the CWD showed increased water stress. Those regions included India, northern China, and Europe. For India, the increase in water stress was attributed to the seasonal gap between runoff and water demand. The increased runoff was concentrated in a few months, while the high irrigation water demand months differed and were much longer. For Europe, the change was attributed to the shift in the timing of snowmelt, which occurred a few months earlier than at present, causing water shortages in early summer.

PROCEEDINGS OF HYDRAULIC ENGINEERING, 2007

We developed a new global river discharge model by merging existing methods and tuning parameters... more We developed a new global river discharge model by merging existing methods and tuning parameters in the model for better reproduction of observed monthly river discharges. The developed model enabled us to estimate amount of renewable water resource with a spatially finer scale than the previous studies. After verifying the effect of the parameter tuning, we applied the developed model to the assessment of water scarcity. The regions judged to have high risk of water scarcity are Sahara desert, Arabian Peninsula, Indus river basin, the northern part of Chile and California Peninsula. Though the regions judged to have high risk of water scarcity were similar to the results of the previous studies, we additionally succeeded in depicting inhomogeneous distribution of water scarcity risk inside the river basins. Since the developed model estimates monthly renewable water resources, monthly variation of water scarcity can be also assessed.

ENVIRONMENTAL SYSTEMS RESEARCH, 2007

Development of a support tool for greenhouse gas emissions control policy to help mitigate the im... more Development of a support tool for greenhouse gas emissions control policy to help mitigate the impact of global warming. Environmental

Key observed and projected climate change impacts are summarized in Tables 24-1, SM24-4, and SM24... more Key observed and projected climate change impacts are summarized in Tables 24-1, SM24-4, and SM24-5 (based on Sections 24.4.1-6).

There are concerns about the impact of climate change on Olympic Games, especially endurance even... more There are concerns about the impact of climate change on Olympic Games, especially endurance events, such as marathons. In recent competitions, many marathon runners dropped out of their races due to extreme heat, and it is expected that more areas will be unable to host the Olympic Games due to climate change. Here, we show the feasibility of the Olympic marathon considering the variations in climate factors, socioeconomic conditions, and adaptation measures. The number of current possible host cities will decline by up to 24% worldwide by the late 21st century. Dozens of emerging cities, especially in Asia, will not be capable of hosting the marathon under the highest emission scenario. Moving the marathon from August to October and holding the games in multiple cities in the country are effective measures, and they should be considered if we are to maintain the regional diversity of the games.

Nature Communications, 2020

More than half of the world’s population currently live in urban areas and are particularly at ri... more More than half of the world’s population currently live in urban areas and are particularly at risk from the combined effects of the urban heat island phenomenon and heat increases due to climate change. Here, by using remotely sensed surface temperature data and social-ecological indicators, focusing on the hot dry season, and applying the risk framework of the Intergovernmental Panel on Climate Change, we assessed the current heat health risk in 139 Philippine cities, which account for about 40% of the country’s total population. The cities at high or very high risk are found in Metro Manila, where levels of heat hazard and exposure are high. The most vulnerable cities are, however, found mainly outside the national capital region, where sensitivity is higher and capacity to cope and adapt is lower. Cities with high levels of heat vulnerability and exposure must be prioritized for adaptation. Our results will contribute to risk profiling in the Philippines and to the understanding...

Environment International, 2020

Climate change mitigation efforts to reduce greenhouse gas (GHG) emissions have associated costs,... more Climate change mitigation efforts to reduce greenhouse gas (GHG) emissions have associated costs, but there are also potential benefits from improved air quality, such as public health improvements and the associated cost savings. A multidisciplinary modeling approach can better assess the co-benefits from climate mitigation for human health and provide a justifiable basis for establishment of adequate climate change mitigation policies and public health actions. An integrated research framework was adopted by combining a computable general equilibrium model, an air quality model, and a health impact assessment model, to explore the long-term economic impacts of climate change mitigation in South Korea through 2050. Mitigation costs were further compared with health-related economic benefits under different socioeconomic and climate change mitigation scenarios. Achieving ambitious targets (i.e., stabilization of the radiative forcing level at 3.4 W/m 2) would cost 1.3-8.5 billion USD in 2050, depending on varying carbon prices from different integrated assessment models. By contrast, achieving these same targets would reduce costs by 23 billion USD from the valuation of avoided premature mortality, 0.14 billion USD from health expenditures, and 0.38 billion USD from reduced lost work hours, demonstrating that health benefits alone noticeably offset the costs of cutting GHG emissions in South Korea.

Japanese Journal of Environmental Education, 2016

Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research), 2017

Japanese Journal of Environmental Education, 2017

Frontiers in Energy, 2018

Waste management is becoming a crucial issue in modern society owing to rapid urbanization and th... more Waste management is becoming a crucial issue in modern society owing to rapid urbanization and the increasing generation of municipal solid waste (MSW). This paper evaluates the carbon footprint of the waste management sector to identify direct and indirect carbon emissions, waste recycling carbon emission using a hybrid life cycle assessment and input-output analysis. China and Japan was selected as case study areas to highlight the effects of different industries on waste management. The results show that the life cycle carbon footprints for waste treatment are 59.01 million tons in China and 7.01 million tons in Japan. The gap between these footprints is caused by the different waste management systems and treatment processes used in the two countries. For indirect carbon footprints, China's material carbon footprint and depreciation carbon footprint are much higher than those of Japan, whereas the purchased electricity and heat carbon footprint in China is half that of Japan. China and Japan have similar direct energy consumption carbon footprints. However, CO 2 emissions from MSW treatment processes in China (46.46 million tons) is significantly higher than that in Japan (2.72 million tons). The corresponding effects of waste recycling on CO 2 emission reductions are considerable, up to 181.37 million tons for China and 96.76 million tons for Japan. Besides, measures were further proposed for optimizing waste management systems in the two countries. In addition, it is argued that the advanced experience that developed countries have in waste management issues can provide scientific support for waste treatment in developing countries such as China.

Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research), 2015

Environmental Research Letters, 2017

Dependence of economic impacts of climate change on anthropogenically directed pathways Jun'ya Ta... more Dependence of economic impacts of climate change on anthropogenically directed pathways Jun'ya Takakura et al-An Occupational Heat-Health Warning System for Europe: The HEAT-SHIELD Platform Marco Morabito et al-Estimation of work-related injury and economic burden attributable to heat stress in Guangzhou, China Rui Ma et al

Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research), 2012

Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research), 2012

Environmental Economics and Policy Studies, 2006

We have been developing a policy support tool, AIM/impact[policy], for use in the integrated asse... more We have been developing a policy support tool, AIM/impact[policy], for use in the integrated assessment of global warming control targets including the stabilization of greenhouse gas concentrations, economically efficient emissions paths to realizing these targets, and consequent impacts and risks of these targets. In this study, a quantitative assessment was made of climate changes and global warming impacts, as well as the timing of greenhouse gas reduction policies, under greenhouse gas stabilization constraints. An energy economic model estimating the optimal emissions path for greenhouse gases and an impact assessment model estimating the impacts of global warming in various fields caused by climate changes under this optimal emissions path were used in our assessment. In contrast to the business-as-usual case, our results showed that in order to maintain greenhouse gas concentrations at less than 500ppm (by volume), reduction volumes must be 3.0GtCeq/year by 2020 and 12.2 GtCeq/year by 2050, indicating an urgent need for a full-scale reduction system.

Environmental Research Letters, 2017

We performed an intercomparison of river discharge regulated by dams under four meteorological fo... more We performed an intercomparison of river discharge regulated by dams under four meteorological forcings among five global hydrological models for a historical period by simulation. This is the first global multimodel intercomparison study on dam-regulated river flow. Although the simulations were conducted globally, the Missouri-Mississippi and Green-Colorado Rivers were chosen as case-study sites in this study. The hydrological models incorporate generic schemes of dam operation, not specific to a certain dam. We examined river discharge on a longitudinal section of river channels to investigate the effects of dams on simulated discharge, especially at the seasonal time scale. We found that the magnitude of dam regulation differed considerably among the hydrological models. The difference was attributable not only to dam operation schemes but also to the magnitude of simulated river discharge flowing into dams. That is, although a similar algorithm of dam operation schemes was incorporated in different hydrological models, the magnitude of dam regulation substantially differed among the models. Intermodel discrepancies tended to decrease toward the lower reaches of these river basins, which means model dependence is less significant toward lower reaches. These case-study results imply that, intermodel comparisons of river discharge should be made at different locations along the river's course to critically examine the performance of hydrological models because the performance can vary with the locations.

Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research), 2014

Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering), 2013

Proceedings of the Symposium on Global Environment, 2008

Future long-terrn changes in global water resources driven by socioeconomic and climatic changes,... more Future long-terrn changes in global water resources driven by socioeconomic and climatic changes, Hydrolog.

Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering), 2011

2 正会員 博士(工学) 国立環境研究所 研究員(〒305-8506 つくば市小野川16-2) 3 正会員 博士(工学) 国立環境研究所 主任研究員(〒305-8506 つくば市小野川16-2)... more 2 正会員 博士(工学) 国立環境研究所 研究員(〒305-8506 つくば市小野川16-2) 3 正会員 博士(工学) 国立環境研究所 主任研究員(〒305-8506 つくば市小野川16-2) 4 正会員 博士(工学) 国立環境研究所 主任研究員(〒305-8506 つくば市小野川16-2) Several reports have assessed water scarcity globally using a widely accepted index on an annual basis, namely, withdrawal-to-water resources ratio (WWR). Here, we ask whether it is appropriate to use the WWR to assess the impact of climate change. Global warming is projected to increase the temporal and spatial variability of precipitation, decrease snowfall, and change the timing of snowmelt. To assess the impact of climate change on global water resources incorporating sub-annual timescale phenomena, this study applies a new water scarcity index on a daily basis termed the cumulative withdrawal-todemand ratio (CWD). Our results indicated that global warming increased the mean annual runoff in 61% of the total land area globally. However, in 22% of the area where runoff increased, the CWD showed increased water stress. Those regions included India, northern China, and Europe. For India, the increase in water stress was attributed to the seasonal gap between runoff and water demand. The increased runoff was concentrated in a few months, while the high irrigation water demand months differed and were much longer. For Europe, the change was attributed to the shift in the timing of snowmelt, which occurred a few months earlier than at present, causing water shortages in early summer.

PROCEEDINGS OF HYDRAULIC ENGINEERING, 2007

We developed a new global river discharge model by merging existing methods and tuning parameters... more We developed a new global river discharge model by merging existing methods and tuning parameters in the model for better reproduction of observed monthly river discharges. The developed model enabled us to estimate amount of renewable water resource with a spatially finer scale than the previous studies. After verifying the effect of the parameter tuning, we applied the developed model to the assessment of water scarcity. The regions judged to have high risk of water scarcity are Sahara desert, Arabian Peninsula, Indus river basin, the northern part of Chile and California Peninsula. Though the regions judged to have high risk of water scarcity were similar to the results of the previous studies, we additionally succeeded in depicting inhomogeneous distribution of water scarcity risk inside the river basins. Since the developed model estimates monthly renewable water resources, monthly variation of water scarcity can be also assessed.

ENVIRONMENTAL SYSTEMS RESEARCH, 2007

Development of a support tool for greenhouse gas emissions control policy to help mitigate the im... more Development of a support tool for greenhouse gas emissions control policy to help mitigate the impact of global warming. Environmental