Tomoko Hasegawa

• Ritsumeikan University

Cities are dependent on food transported domestically or internationally. However, little is known about how the burden of transporting food to cities will changes under future socio-economic and climatic conditions. Here we present the current transport loads of major commodities (wheat and rice) and their projections in 2050 for 208 world’s major...

The impact of ambient air pollution on human health, particularly fine particulate matter (PM2.5) and tropospheric ozone (O3), is a critical global concern. Atmospheric chemical transport models (CTMs) are widely used to predict air pollutant concentrations and assess associated health risks. However, there is a need to better understand how the ho...

Climate change intensifies fire smoke, emitting hazardous air pollutants that impact human health. However, the global influence of climate change on fire-induced health impacts remains unquantified. Here we used three well-tested fire–vegetation models in combination with a chemical transport model and health risk assessment framework to attribute...

Climate mitigation is reported to benefit biodiversity globally. However, the impacts of mitigation measures based on large-scale land-use modifications can be concentrated in the regions where they are introduced, resulting in regional mismatches between mitigation efforts and biodiversity benefits. Here, we evaluated the impacts of large-scale de...

Based on an extensive model intercomparison, we assessed trends in biodiversity and ecosystem services from historical reconstructions and future scenarios of land-use and climate change. During the 20th century, biodiversity declined globally by 2 to 11%, as estimated by a range of indicators. Provisioning ecosystem services increased several fold...

Food production, particularly cattle husbandry, contributes significantly to air pollution and its associated health hazards. However, making changes in dietary habits, such as reducing red meat consumption and minimizing food waste, can lead to substantial improvements in both air quality and human health. In this study, we explored the impact of...

Afforestation is a major carbon dioxide removal technology but can negatively affect food and land systems. Here, we used an integrated assessment model to quantitatively demonstrate how the selection of forest type to use in afforestation could increase global carbon sequestration without compromising global food and land sustainability. Our findi...

Fire emits hazardous air pollutants, the most dominant of which is fine particulate matter of diameter ≤2.5 μm (PM2.5). PM2.5 is a great concern due to its adverse effects on public health. Previous studies have examined the health burden from fire-related PM2.5 for the historical period; however, future global mortality associated with fire-PM2.5,...

The implementation of Climate Change mitigation measures in Japan leads to a heavy burden on low-income groups. Therefore, there are concerns that mitigation measures have a regressive impact on household consumption. Although there are a variety of energy scenarios to achieve long-term decarbonization goals, previous studies targeting Japan have n...

In 2019, Agriculture, forestry and other land-use sectors account for 22% of global anthropogenic green-house gases emission, and its proportion in developing countries is high. Agriculture sector is expected to play an important role to reduce greenhouse gases emissions. In this study, we aim to reveal potential reduction amounts of methane and ni...

Climate change impacts and its mitigation measures can exacerbate poverty by causing consumption losses among low-income groups through changes in average income, income distribution, and prices. It’s unclear how poverty changes when these impacts are considered comprehensively, and which factors affect poverty and to what extent. This study invest...

Recent criticisms have suggested that future emissions are unlikely to lead to the warmest climate scenario available (SSP5-8.5), which has resulted in the second highest scenario (SSP3-7.0) receiving increased attention. The distinctiveness of SSP3-7.0 has not been well recognized, but it is relevant for the proper interpretation of studies that u...

Wildfires affect human health by emitting hazardous air pollutants. The contribution of climate change to global fire-induced health impacts has not been quantified so far. Here, we used three fire-vegetation models in combination with a chemical transport model and health risk assessment framework to attribute global human mortality from fire fine...

What will be the aggregated cost of climate change in achieving the Paris Agreement, including mitigation, adaptation, and residual impacts? Several studies estimated the aggregated cost but did not always consider the critical issues. Some do not address non-market values such as biodiversity and human health, and most do not address differentiati...

Many countries have set ambitious long-term emissions reduction targets for reaching the goal in alignment with the Paris Agreement. However, large-scale emission reduction efforts may influence poverty by various economic channels. Here, we show the extent to which climate change mitigation, excluding climate change impacts, has the potential to i...

Afforestation is considered as a major carbon dioxide removal (CDR) technology, but if implemented inappropriately in large scale, can negatively affect food and land systems. Here we quantitatively showed how a forest-type selection in afforestation would enlarge the global carbon sequestration and affect global food and land systems and sustainab...

Numerical scenarios generated by Integrated Assessment Models describing future energy and land-use systems that attain climate change mitigation goals have been considered important sources of guidance for climate policymaking. The climate change mitigation cost is one of the concerns in the emissions reduction efforts. However, how to moderate cl...

Fires and their associated carbon and air pollutant emissions have a broad range of environmental and societal impacts, including negative effects on human health, damage to terrestrial ecosystems, and indirect effects that promote climate change. Previous studies investigated future carbon emissions from the perspective of response to climate chan...

Working paper analysing the economic implications of the proposed 30% target for areal protection in the draft post-2020 Global Biodiversity Framework

The agriculture and livestock sector accounts for 24% of anthropogenic greenhouse gases in the global warming problem. Therefore, we estimated the emissions of CH₄ and N₂O in the agriculture and livestock sectors in the Latin America region, which have not been studied before, the amount of possible emission reductions, and effective countermeasure...

Tropospheric ozone, which has been increasing in recent years, has a strong oxidizing power and is said to have a negative impact on crops, especially on crop yields. This paper clarifies the effects of changes in tropospheric ozone concentration associated with climate change mitigation measures on food consumption and the population at risk of hu...

It has been reported that the introduction of GHG reduction measures in the agriculture and livestock sectors will play an important role in mitigating greenhouse gas (GHG) emissions in Asia, but no evaluation of countermeasure technologies at the national level in all Asian regions has yet been conducted. Therefore, this study clarified the amount...

Climate change can cause economic losses and increase poverty. However, climate change mitigation measures can also cause economic losses and increase poverty. Previous studies have not assessed the impact of climate change and climate change mitigation on poverty simultaneously. This study aimed to quantitatively assess the impact of climate chang...

Kyoto City has announced its goal of achieving net zero carbon dioxide emissions by 2050, ahead of all other cities in Japan. Previous studies have quantified the city's net-zero emissions of energy-related carbon dioxide. In this study, we developed a method for creating decarbonized society scenarios that also take into account the waste sector....

Tropospheric ozone is known to have a negative impact on plant CO2 uptake. On the other hand, climate change mitigation generally lead to reductions in emissions of ozone precursors such as NOx, thereby reducing ozone concentrations. Howerver, ozone impacts on CO2 uptake by terrestrial ecosystems on by vegetation has not been interpreted in terms o...

Agricultural sector accounts for approximately 70 % of global water withdrawals, which shows that food production requires a large amount of freshwater resources. Food import raises the dependence on foreign water resources because of indirect water consumption for importing countries in exchange for the increase of water use to produce food produc...

Existing climate change mitigation scenarios for attaining the 1.5°C goal generally phase out hydrocarbon use through decarbonization of the energy system to eliminate fossil fuel usage. However, they require rapid changes in energy-demand technologies and human behaviors or extensive reliance on bioenergy for carbon dioxide removal (CDR). Carbon c...

Many countries have taken stringent climate policies to minimize the risks by climate change. But these policies could burden households and the poor with the extra costs and threaten their wellbeing. However, the consequences of climate policies on poverty and welfare loss are seldom presented in stringent long-term climate change mitigation proje...

Bioenergy is projected to have a prominent, valuable, and maybe essential, role in climate management. However, there is significant variation in projected bioenergy deployment results, as well as concerns about the potential environmental and social implications of supplying biomass. Bioenergy deployment projections are market equilibrium solution...

Biomass energy is projected to be a critical resource for defossilization of the energy system. While urban area extension and land conservation would constrain potential biomass supply, there is little understanding of their impacts. This paper presents global and regional bioenergy supply potential estimates by newly implementing urban area expan...

Earlier studies have noted potential adverse impacts of land-related emissions mitigation strategies on food security, particularly due to food price increases—but without distinguishing these strategies’ individual effects under different conditions. Using six global agroeconomic models, we show the extent to which three factors—non-CO2 emissions...

Current many climate change mitigation scenarios that meet so-called 2°C or 1.5°C target intending to keep global average temperature rise below 2 or 1.5 °C show that around 20-30% of total energy would be supplied by bioenergy. And it is said that the reduction of meat consumption will reduce land use of farmlands and pastures, which can be used f...

It has been reported that emission reductions in the agricultural and livestock sectors, which produce non-carbon dioxide emissions, will play an important role in achieving net-zero global greenhouse gas (GHG) emissions. In this study, we estimated the potential GHG emission reductions and costs associated with GHG reductions in the agricultural a...

The effect of reducing GHG emissions by limiting the consumption of livestock products has been reported. However, the specific impact on the food system and land use system that are the sources of GHG emissions has not been evaluated. The purpose of this paper is to clarify the impact of restricted consumption of livestock products on the environm...

Conserving biodiversity is one of the great concerns for developing sustainable society. This study attempts to identify in what regions and what measures are effective to conserve the biodiversity by integrating economic, land-use and biodiversity models in a single modeling framework. More specifically, we implemented scenarios to change the diet...

In recent years, a large amount of attention has been paid to the health effects of PM2.5 and the agricultural effects of tropospheric ozone as effects of air pollution. However, the effects of differences in the horizontal resolution of the chemical transport models used for the above effects have not yet been clarified. Therefore, this study calc...

In the Paris Agreement adopted in 2015, it is agreed that efforts should be made to keep the global average temperature rise well below 2 degrees Celsius compared to pre-industrial levels, and to limit it to 1.5 degrees Celsius. To achieve climate mitigation in line with the Paris Agreement, net zero emissions need to be achieved in mid century. Mo...

Carbon taxation has been attracting attention as a measure to reduce greenhouse gas emissions. Although it can efficiently reduce emissions, concerns are that the impact of carbon taxes could be greater for lower-income groups because the impact is biased toward essential goods and services. Therefore, this study clarified the impact of carbon taxe...

Tropospheric surface ozone is a strong oxidizing agent, and its chemical properties have adverse effects on plants, especially in terms of food supply. In this paper, we investigated the effects of climate change and its mitigation measures through associated changes in crop yields due to changes in ozone concentrations on global food consumption a...

Delaying climate mitigation action and allowing a temporary overshoot of temperature targets require large-scale carbon dioxide removal (CDR) in the second half of this century that may induce adverse side effects on land, food and ecosystems. Meanwhile, meeting climate goals without global net-negative emissions inevitably needs early and rapid em...

Global emissions scenarios play a critical role in the assessment of strategies to mitigate climate change. The current scenarios, however, are criticized because they feature strategies with pronounced overshoot of the global temperature goal, requiring a long-term repair phase to draw temperatures down again through net-negative emissions. Some i...

Trade liberalization in the early 21st century increased the adaptation capacity of global food systems to climate change; further liberalization and trade facilitation could help to avoid dozens of millions being undernourished at mid-century. The global trade agenda should explicitly include climate change adaptation to achieve SDG 2 Zero Hunger....

Bioenergy with carbon capture and storage (BECCS) is crucial in many stringent climate scenarios. Although irrigation can enhance BECCS potential, where and to what extent it can enhance global BECCS potential are unknown when constrained by preventing additional water stress and suppressing withdrawal of nonrenewable water resources. With a spatia...

While nitrogen inputs are crucial to agricultural production, excess nitrogen contributes to serious ecosystem damage and water pollution. Here, we investigate this trade-off using an integrated modelling framework. We quantify how different nitrogen mitigation options contribute to reconciling food security and compliance with regional nitrogen su...

Climate change is expected to increase the frequency, intensity and spatial extent of extreme climate events, and thus is a key concern for food production. However, food insecurity is usually analysed under a mean climate change state. Here we combine crop modelling and climate scenarios to estimate the effects of extreme climate events on future...

The movement toward low-carbon human system over the last decade has been remarkable. Numerical scenarios describing future energy and land-use systems that attain climate change mitigation goals have been considered important sources of guidance for climate policymaking. However, no clear strategy for materialising green growth, i.e. vastly reduci...

One of the major barriers to climate communication is that climate change is often presented to the public in such a way that impacts seem distant in time. To improve how climate change resonates with people, we propose a simple indicator: how many extreme events (hot days and heavy precipitation days) are grandchildren projected to experience that...

Process-based models are powerful tools for simulating the economic impacts of climate change, but they are computationally expensive. In order to project climate-change impacts under various scenarios, produce probabilistic ensembles, conduct online coupled simulations, or explore pathways by numerical optimization, the computational and implement...

Globally, many parts of fire emissions are driven by deforestation. However, few studies have attempted to evaluate deforestation and vegetation degradation fires (DDF) and predict how they will change in the future. In this study, we expanded a fire model used in the Community Land Model to reflect the diverse causes of DDF. This enabled us to dif...

Mitigation pathways by Integrated Assessment Models (IAMs) describe future emissions that keep global warming below specific temperature limits and are compared with countries’ collective greenhouse gas (GHG) emission reduction pledges. This is needed to assess mitigation progress and inform emission targets under the Paris Agreement. Currently, ho...

A Correction to this paper has been published: https://doi.org/10.1038/s41558-020-00981-9.

Even though enormous expectations for greenhouse gas mitigation in the land use sector exist at the same time worries about potential implications for sustainable development have been raised as many Sustainable Development Goals (SDGs) are closely tied to developments in the sector. Here we assess the implications of achieving selected key SDG ind...

Actions tackling with climate change can cause co-benefits and trade-offs with Sustainable Development Goals (SDGs) concerned with air pollution, water scarcity, food security, land use, and sustainable energy. Such interactions can be greatly influenced by socioeconomic conditions. The impacts of socioeconomic conditions on multiple SDGs have not...

The greenhouse gas (GHG) reduction measures in the agriculture, forestry and land use sector is expected to play an important role in climate change mitigaton. Although the effect of emission reduction on the production side has been analyzed, the ones on the consumption side has not yet been examined. Here, we aim to estimate the effects of GHG em...

Current many climate change mitigation scenarios that meet so-called 2°C or 1.5°C target intending to keep global average temperature rise below 2 or 1.5 °C show that around 20-30% of total energy would be supplied by bioenergy. Despite a critical role of bioenergy in the climate change mitigation, the secondary environmental impacts of large-scale...

Large-scale introduction of renewable energy is necessary to achieve the 2°C target set in the Paris Agreement. However, most of the calculations of potential production of renewable energy in existing studies assumed that land use would remain the same in the present and future. In this study, we estimated the global wind and solar energy potentia...

Agriculture, Forestry and Other Land-use (AFOLU) are thought to play a vital role in long-term GHG emissions reduction, especially for their importance in non-CO2 emissions, bioenergy supply and carbon sequestration realized by afforestation. Several studies have noted potential adverse impacts of land-related emissions mitigation on food security,...

Allowing delayed climate mitigation actions and overshoot of temperature targets requires large scale negative carbon emissions that may induce adverse side-effects on land, food and ecosystems in the second half of this century. Meanwhile, meeting climate goals without net negative emissions inevitably needs the implementation of early and quick e...

Global emissions scenarios play a critical role in the assessment of strategies to mitigate climate change and their related societal transformations. The current generation of scenarios, however, are criticized because they rely heavily on net negative CO2 emissions (NNCE) that result from allowing temperature limits to be temporarily exceeded. In...

Long-term global scenarios have underpinned research and assessment of global environmental change for four decades. Over the past ten years, the climate change research community has developed a scenario framework combining alternative futures of climate and society to facilitate integrated research and consistent assessment to inform policy. Here...

Large-scale deployment of bioenergy plantations would have adverse effects on water resources. There is an increasing need to ensure the appropriate inclusion of the bioenergy crops in global hydrological models. Here, through parameter calibration and algorithm improvement, we enhanced the global hydrological model H08 to simulate the bioenergy yi...

We present an overview of results from 11 integrated assessment models (IAMs) that participated in the 33rd study of the Stanford Energy Modeling Forum (EMF-33) on the viability of large-scale deployment of bioenergy for achieving long-run climate goals. The study explores future bioenergy use across models under harmonized scenarios for future cli...

In the twenty-first century, modern bioenergy could become one of the largest sources of energy, partially replacing fossil fuels and contributing to climate change mitigation. Agricultural and forestry biomass residues form an inexpensive bioenergy feedstock with low greenhouse gas (GHG) emissions, if harvested sustainably. We analysed quantities...

Bioenergy is expected to play an important role in the achievement of stringent climate-change mitigation targets requiring the application of negative emissions technology. Using a multi-model framework, we assess the effects of high bioenergy demand on global food production, food security, and competition for agricultural land. Various scenarios...

In order to project climate-change impacts under a wide-range of scenarios or conduct on-line coupled simulations, the computational and implementation cost of economic impact calculations should be reduced. To do so, in this study, we developed various emulators that mimic simulation outputs, namely economic models coupled with bio/physical proces...

Background: Modeling suggests that climate change mitigation actions can have substantial human health benefits that accrue quickly and locally. Documenting the benefits can help drive more ambitious and health-protective climate change mitigation actions; however, documenting the adverse health effects can help to avoid them. Estimating the health...

Human land use activities have resulted in large changes to the biogeochemical and biophysical properties of the Earth's surface, with consequences for climate and other ecosystem services. In the future, land use activities are likely to expand and/or intensify further to meet growing demands for food, fiber, and energy. As part of the World Clima...

A carbon tax is one of the measures used to reduce GHG emissions, as it provides a strong political instrument for reaching the goal, stated in the Paris Agreement, of limiting the global mean temperature increase to well below 2 °C. While one aspect of a carbon tax is its ability to change income distribution, no quantitative assessment has been m...

Increased efforts are required to prevent further losses to terrestrial biodiversity and the ecosystem services that it provides1,2. Ambitious targets have been proposed, such as reversing the declining trends in biodiversity³; however, just feeding the growing human population will make this a challenge⁴. Here we use an ensemble of land-use and bi...

Historical increases in agricultural production were achieved predominantly by large increases in agricultural productivity. Intensification of crop and livestock production also plays a key role in future projections of agricultural land use. Here, we assess and discuss projections of crop yields by global agricultural land-use and integrated asse...

Synergies and trade-offs exist between climate mitigation actions and target indicators of the Sustainable Development Goals (SDGs). Some studies have assessed such relationships, but the degree of such interaction remains poorly understood. Here, we show the SDG implications associated with CO 2 emissions reductions. We developed ‘marginal SDG-emi...

Bioenergy could play an important role for Japan's long-term mitigation strategy and energy supply but understanding of Japan's domestic bioenergy supply capacity is limited. Here, we estimated Japan's technical and economically feasible bioenergy potential throughout this century. We used an integrated assessment framework covering various feedsto...

International trade enables us to exploit regional differences in climate change impacts and is increasingly regarded as a potential adaptation mechanism. Here, we focus on hunger reduction through international trade under alternative trade scenarios for a wide range of climate futures. Under the current level of trade integration, climate change...

Large-scale deployment of bioenergy plantations would have adverse effects on water resources. There is an increasing need to ensure the appropriate inclusion of the bioenergy crops in global hydrological models. Here, through parameter calibration and algorithm improvement, we enhanced the global hydrological model H08 to simulate the bioenergy yi...

Global economic models have been increasingly used to project food and agricultural developments for long term-time horizons, but food security aspects have often been limited to food availability projections. In this paper, we propose a broader framework to explore the future of food and nutrition security with a focus on food availability, food a...

In 2015, El Niño contributed to severe droughts in equatorial Asia (EA). The severe droughts enhanced fire activity in the dry season (June–November), leading to massive fire emissions of CO2 and aerosols. Based on large event attribution ensembles of the MIROC5 atmospheric global climate model, we suggest that historical anthropogenic warming incr...

Abstract. Human land-use activities have resulted in large changes to the biogeochemical and biophysical properties of the Earth surface, with consequences for climate and other ecosystem services. In the future, land-use activities are likely to expand and/or intensify further to meet growing demands for food, fiber, and energy. As part of the Wor...

Despite the scientific consensus on the extinction crisis and its anthropogenic origin, the quantification of historical trends and of future scenarios of biodiversity and ecosystem services has been limited, due to the lack of inter-model comparisons and harmonized scenarios. Here, we present a multi-model analysis to assess the impacts of land-us...