Mikiko Kainuma

• National Institute for Environmental Studies

This chapter frames the context, knowledge-base and assessment approaches used to understand the impacts of 1.5°C global warming above pre-industrial levels and related global greenhouse gas emission pathways, building on the IPCC Fifth Assessment Report (AR5), in the context of strengthening the global response to the threat of climate change, sus...

Achieving long-term climate mitigation goals in Japan faces several challenges, starting with the uncertain nuclear power policy after the 2011 earthquake, the uncertain availability and progress of energy technologies, as well as energy security concerns in light of a high dependency on fuel imports. The combined weight of these challenges needs t...

The Paris Agreement introduces long-term strategies as an instrument to inform progressively more ambitious emission reduction objectives, while holding development goals paramount in the context of national circumstances. In the lead up to the twenty-first Conference of the Parties, the Deep Decarbonization Pathways Project developed mid-century l...

This study assesses Japan's emission pathways aimed at net-zero emissions by 2050, as implied by the Paris Agreement's global climate goal of pursuing efforts to limit the temperature rise to 1.5 °C. Based on a scenario analysis performed using AIM/Enduse [Japan], Japan's energy supply sector requires a radical transformation, including reliance on...

This study assesses implications of the target reduction in GHG emissions by 2030 included in Japan's Intended Nationally Determined Contribution (INDC) for long-term low emission pathways toward 2050, as well as feasibility of the 2030 target itself using AIM/Enduse model. Scenario analysis by 2030 suggests that implementing the INDC could consoli...

This book summarizes assessments of the Paris Agreement to provide an excellent introduction to this research field. The AIM/CGE (Asia-Pacific Integrated Modeling /Computable General Equilibrium) model, which is the core of AIM modeling framework, is used for the assessment. The first part focuses on global issues, presenting both short-term (a few...

It is clear that much more drastic and early actions than those that are presently being undertaken are needed to limit the average global temperature increase to 1.5 °C above pre-industrial levels. The Asian region, accounting for a significant portion of global greenhouse gas emissions and growing at a rapid economic pace, has a major role to pla...

Japan submitted its (Intended) Nationally Determined Contributions ((I)NDC) that is 26% reduction of GHG in 2030 compared with the 2013 level on July 2015. In this analysis, Japan’s NDC is assessed using the technology selection model (AIM/Enduse) and the computable general equilibrium model (AIM/CGE) developed by AIM (Asia-Pacific Integrated Model...

This book analyzes the roles of technologies and their prevalence in implementing intended nationally determined contributions (INDCs), estimates the economic impacts and co-benefits of INDCs, clarifies the gaps between the current INDCs and the long-term target of the Paris Agreement to stay well below 2 °C, and investigates measures to narrow the...

Toward the achievement of the 2 °C target, Japan has set several GHG mitigation targets after ratifying the Kyoto Protocol. In 2008, in order to discuss the GHG mitigation target in 2020 at COP15 held in Copenhagen, the committee on the mid- and long-term target in Japan was organized at the Cabinet Secretariat. At that discussion, the proposed six...

This paper presents the overview of the Shared Socioeconomic Pathways (SSPs) and their energy, land use, and emissions implications. The SSPs are part of a new scenario framework, established by the climate change research community in order to facilitate the integrated analysis of future climate impacts, vulnerabilities, adaptation, and mitigation...

This study quantifies the Shared Socioeconomic Pathways (SSPs) using AIM/CGE (Asia-Pacific Integrated Assessment/Computable General Equilibrium). SSP3 (regional rivalry) forms the main focus of the study, which is supposed to face high challenges both in mitigation and adaptation. The AIM model has been selected as the model to quantify the SSP3 ma...

This chapter describes energy efficiency and conservation strategies in Japan by showing the historical trends of energy consumption and energy efficiency improvements. The Japanese experience demonstrates that efforts to solve environmental problems have served to improve energy efficiency in various fields. A mitigation scenario to halve global G...

For countries without sufficient fossil fuel resources such as Japan, climate policies in the mid- to long term need to satisfy requirements not only for decarbonisation but also for energy security in the context of limitations on renewable energies and nuclear power. This study assesses the feasibility of decarbonization pathways to 2050 and thei...

Governments worldwide have agreed that international climate policy should aim to limit the increase of global mean temperature to less than 2oC with respect to pre-industrial levels. The purpose of this paper is to analyse the emission reductions and related energy system changes in various countries in pathways consistent with the 2oC target. We...

Greenhouse gas (GHG) emissions from Asia accounted for approximately 38 % of global emissions in 2005. Considering the rapid economic growth expected in the coming decades, emissions from Asia in 2050 are projected to double the 2005 levels if efforts are not made toward achieving low-carbon societies (LCSs). The reduction of emissions in Asia is i...

The book summarizes findings of research of 16 country teams on deep decarbonization pathways, aiming at limiting the global warming by 2 degrees Celsius.

This supplementary material contains case studies presenting specific aspects of the DDPP country pathways. They illustrate and complement the cross-cutting analysis included in the 2015 DDPP synthesis report

Stabilizing greenhouse gas (GHG) concentrations will require large-scale transformations in human societies, from the way that we produce and consume energy to how we use the land surface. A natural question in this context is what will be the .transformation pathway. towards stabilization; that is, how do we get from here to there? The topic of th...

Using a bottom-up model, the effectiveness of carbon tax policy and a policy mix related to a carbon tax in Japan are assessed to reduce CO2 emissions to the targeted level in the first commitment period of the Kyoto Protocol. In this simulation, only existing technologies and practical new technologies are treated. From the results of the bottom-u...

Japan’s long-term CO2 emission reduction scenarios are assessed with a computable general equilibrium model with recursive dynamics, which was modified in order to assess the effects of renewable energy supply. The period of assessment is from 2000 to 2050 and the increase of gross domestic product per capita was assumed to be 2% per year. The foll...

This report stated the key concepts of decarbonization of 15 leading economies aiming at limiting global warming by 2 degrees Celsius. The report was presented to UN Secretary-General Ban Ki-moon in support of the UN Climate Leaders’ Summit in New York on September 23, 2014 and the UNFCCC COP21, where the historic Paris Climate Agreement was signed...

In this paper, we assessed the technological feasibility and economic viability of the mid-term (until 2050) GHG emission reduction target required for stabilization of radiative forcing at 2.6 W/m2. Given the apparent uncertainty surrounding the future deployment of nuclear and CCS technologies, we intensively investigated emission reduction scena...

This paper provides an overview of the AMPERE modeling comparison project with focus on the implications of near-term policies for the costs and attainability of long-term climate objectives. Nine modeling teams participated in the project to explore the consequences of global emissions following the proposed policy stringency of the national pledg...

The feasibility of two low-carbon society (LCS) scenarios, one with and one without nuclear power and carbon capture and storage (CCS), is evaluated using the AIM/Enduse[Global] model. Both scenarios suggest that achieving a 50% emissions reduction target (relative to 1990 levels) by 2050 is technically feasible if locally suited technologies are i...

In this paper, we explore GHG emission scenarios up to 2050 in Asia and the world as part of the Asian Modeling Exercise and assess technology options for meeting a 2.6 W/m2 radiative forcing target using AIM/Enduse[Global] and AIM/Impact[Policy]. Global GHG emissions in 2050 are required to be reduced by 72% relative to a reference scenario, which...

Asian Modeling Exercise (AME) studies show feasible GHG emissions pathways consistent with the 2 degrees centigrade global stabilization target. The aim of the low carbon society subgroup is to propose frameworks, modeling methodologies, and workable roadmaps that will transform in-situ socioeconomic development to a sustainable low carbon society....

This study focuses on low-carbon transitions in the mid-term and analyzes mitigation potentials of greenhouse gas (GHG) emissions in 2020 and 2030 in a comparison based on bottom-up-type models. The study provides in-depth analyses of technological mitigation potentials and costs by sector and analyzes marginal abatement cost (MAC) curves from 0 to...

This paper presents the possibility for Thailand to become a low-carbon society (LCS). The methodology involves development of current CO2emission inventory, and quantification of socio-economic activity level in 2030. In this study, the increase of CO2 emissions is estimated based on i) 2030 BAU (business-as-usual) without mitigation measures, and...

We present the greenhouse gas concentrations for the Representative Concentration Pathways (RCPs) and their extensions beyond 2100, the Extended Concentration Pathways (ECPs). These projections include all major anthropogenic greenhouse gases and are a result of a multi-year effort to produce new scenarios for climate change research. We combine a...

Representative Concentration Pathway 6.0 (RCP6) is a pathway that describes trends in long-term, global emissions of greenhouse gases (GHGs), short-lived species, and land-use/land-cover change leading to a stabilisation of radiative forcing at 6.0 Watts per square meter (Wm−2) in the year 2100 without exceeding that value in prior years. Simulated...

This paper summarizes the development process and main characteristics of the Representative Concentration Pathways (RCPs), a set of four new scenarios developed for the climate modeling community as a basis for long-term and near-term modeling experiments. The four RCPs together span the range of year 2100 radiative forcing values found in the ope...

In this study, we simulate global CO2 emissions and their reduction potentials in the industrial sector up to the year 2030. Future industrial CO2 emissions depend on changes in both technology and industrial activity. However, earlier bottom-up analyses mainly focused on technology change. In this study, we estimate changes in both technology and...

Long-term scenarios developed by integrated assessment models are used in climate research to provide an indication of plausible long-term emissions of greenhouse gases and other radiatively active substances based on developments in the global energy system, land-use and the emissions associated with these systems. The phenomena that determine the...

Chapter 4 builds upon the previous two chapters by examining a possible ‘emissions gap’ in 2020 between emission levels consistent with temperature limits and expected emissions resulting from the pledges. It then goes on to explore policy options for narrowing the size of the gap. This Chapter shows that, in the majority of cases, there is a gap...

In this paper we draw up future roadmaps for technologies, policies, and optimal investment timing toward the achievement of a low-carbon society (LCS) in Japan by 2050. Future pathways for Japan to follow are calculated using an analytical model based on a backcasting methodology. Early actions can lead to pathways for minimizing the costs toward...

We present and discuss a new dataset of gridded emissions covering the historical period (1850–2000) in decadal increments at a horizontal resolution of 0.5° in latitude and longitude. The primary purpose of this inventory is to provide consistent gridded emissions of reactive gases and aerosols for use in chemistry model simulations needed by clim...

Advances in the science and observation of climate change are providing a clearer understanding of the inherent variability of Earth's climate system and its likely response to human and natural influences. The implications of climate change for the environment and society will depend not only on the response of the Earth system to changes in radia...

This study analyzes the role of energy intensity improvement in the short term (to the year 2020) and midterm (to the year 2050) in the context of long-term greenhouse gases (GHG) stabilization scenarios. The data come from the latest Emissions Scenarios Database and were reviewed in the Fourth Assessment Report (AR4) by the Intergovernmental Panel...

The purpose of this study is to estimate mitigation of greenhouse gases (GHGs) in various sectors in the world regions and to evaluate marginal abatement costs (MAC) through 2020. The study estimates MAC based on a bottom-up approach with a mitigation options database. It sets a technology-frozen case as the baseline and estimates reduction potenti...

The purpose of this article is to describe the methodology used for generating the IPCC AR5 emissions, together with information on their availability.

This article envisions a future in which advances in technology and urban development have transformed Japanese society by 2050, resulting in significant greenhouse gas reductions. Pathways leading Japan towards a low-carbon society are calculated using a scenario approach based on 'back-casting' techniques. It is possible to reach a 70% reduction...

This paper considers three questions concerning a low-carbon society. The first is the implication of a 50% reduction in greenhouse gases (GHGs) by 2050. In the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report, released in 2007 (IPCC 2007b; http://www.gtp89.dial.pipex.com/chpt.htm), the suggested limit of increase in averag...

This article assesses emissions scenarios in the literature, originally documented in the scenario database that was developed more than 7 years ago. The original scenario assessment and literature review has been used, among other things, as the basis for the quantification of the Intergovernmental Panel on Climate Change (IPCC) Special Report on...

The objectives of this study were to carry out a review of mitigation scenarios that have emerged since the Intergovernmental Panel on Climate Change (IPCC) Third Assessment Report (TAR), to update the current Emissions Scenarios Database with these scenarios, and to analyze emissions and mitigation scenarios. This article first discusses the chara...

Non-CO2 gas (CH4, N2O and F gas) emissions account for 25 percent of all greenhouse gas in the year of 2000. Main sources of CH4 and N2O emissions are agriculture-related activities such as enteric fermentation, paddy rice cultivation, soil management. A recursive dynamic CGE (Computer General Equilibrium) model has been developed to analyze greenh...

Using a global dynamic optimization model that includes a notion of endogenous energy-saving investments, economic impacts and energy-system changes are assessed under several policy cases where CO2 concentration is stabilized at the 450, 500, and 550 ppm levels by the year 2100. The effect of increased investments in energy-saving technologies on...

Several climate change stabilization pathways are examined by the Asia-Pacific integrated model . An urgent task is to take action to combat global warming as it is an irreversible process and, once it occurs, the probability is very high that it will have multiplier effects that will further expand its impact. It is necessary to consider the many u...

This paper analyzes the economic and climatic impacts of the EMF 19 emission scenarios. A reference scenario, three emission scenarios targeting 550 ppmv atmospheric concentration, and three tax scenarios are analyzed. The profiles of energy consumption and economic losses of each policy scenario are compared to the reference scenario. The model al...

1 Summary. The Asia-Pacific Integrated Model (AIM) is a set of computer simulation models for assessing policy options on sustainable development particularly in the Asia-Pacific region. It started as a tool to evaluate policy options to mitigate climate change and its impacts, and extended its function to analyze other environmental issues such as...

1 Summary. The model for assessing the future environmental loads based on the past socio-economic trends has been developed. By using this model, the environmental trends until 2032 in the Asia-Pacific 42 countries have been estimated. This AIM/Trend model has characteristics of econometric model and communication tool to enhance discussions and s...

The AIM/Enduse model has been frequently applied to Japanese policy making processes. This chapter illustrates three of these applications. First, the effects of carbon tax and subsidies to reduce CO2 emissions in Japan are introduced. CO2 emissions through 2010 are estimated for four cases: reference case, market case, carbon tax case, and carbon...

This analysis evaluates the economic and environmental impacts of climate change policies. Firstly, the economic impacts of the Kyoto Protocol are analyzed to assess the short-term effects of climate change policies. It is found that the GDP loss to Japan, the USA, the EU, and Russia will be 0.42%, 0.56%, 0.44%, and 0.25%, respectively, if the Anne...

Several teams have been developing AIM models in different countries to analyze their own policy options to mitigate greenhouse gas emissions. Although they need to collect their own data, there are a lot of data that can be shared. The AIM/Common Database, consisting of common formats and code system, has therefore been developed as a tool for AIM...

AIM/Enduse is a technology selection framework for analysis of country-level policies related to greenhouse gas emissions mitigation and local air pollution control. It can also assist in energy policy analysis. It simulates flows of energy and materials in an economy, from supply of primary energy and materials, through conversion and supply of se...

The Asia–Pacific Integrated Model (AIM) brings together more than 20 computer simulation models for development and analysis of policy in such diverse fields as climate change mitigation, air pollution abatement, and ecosystem preservation. This first book in a series on the development of AIM focuses on climate change issues and the evaluation of...

An end-use energy demand model has been developed to evaluate policy options to reduce CO2 emissions. The model can evaluate relations between CO2 emissions and energy consumption technologies. It can also analyze effects of introducing various reduction policies, such as imposing carbon taxes and granting subsidies. Under various policy options, C...

In order to support a special project for developing a new set of long-term GHGs emission scenarios in IPCC, the new general equilibrium model, which can analyze the land use change, has been developed. According to the long-term land use scenario projected by the model, greenhouse gas (CO 2 , NO x , SO x , CH 4 , CO, and N 2 O) emissions from land...

The Asian-Pacific Integrated Model (AIM) has been developed for predicting greenhouse gas emissions and evaluating policy measures to reduce them. Two socioeconomic scenarios were assumed and CO2 emissions were predicted based on these scenarios and policy intervention assumptions. It is found that mitigating CO2 emissions by 6% to the 1990 level i...

This study estimates the extent to which embodied CO2 emissions are increased or reduced when a socioeconomic structural change occurs. Embodied CO2 emissions were estimated by Input–Output models (I–O models) and a General Equilibrium model (GE model), and the respective results were compared. The embodied CO2 emissions differ greatly depending on...

An end-use energy model is presented for assessing policy options to reduce greenhouse gas emissions. This model evaluates the effects of imposing a carbon tax on various carbon-emitting technologies in order to reduce CO₂ emissions. It also estimates the effects of a carbon tax in combination with subsidies. The problem can be formulate...

The AIM/top-down model is a recursive general equilibrium model used to analyze the post-Kyoto scenarios presented by EMF16. Differences among scenarios mainly arise from the setting of emission trading. Japan's marginal cost is the highest among the Annex I countries except New Zealand, where a relatively high emission reduction is necessary, whil...

As air pollution is foreseen to be one of the most important problems in the Asia-Pacific region, several alternative policies are analyzed to find ways to tackle this problem. The major tool used in this study is the Asian-Pacific Integrated Model (AIM). Policy options to reduce the emissions of air pollutants include utilization of clean technolo...

The need to respond to climate changes is now a matter of common recognition throughout the world. After several years of negotiations, agreement was reached on the Kyoto Protocol in 1997 in Japan. The Protocol is regarded as an important step toward meeting the objective of stabilizing greenhouse gas concentrations in the atmosphere. The paper dis...

AIM (Asian-Pacific Integrated Model) has been developed for predicting greenhouse gas emissions and evaluating policy measures to reduce them. Two socio-economic scenarios were assumed and CO2 emissions were predicted based on these scenarios and policy intervention assumptions. It is found that mitigating CO2 emissions without scaling back product...

筆者らは先に, エネルギー消費技術の進展と二酸化炭素排出量との関係を定量的に評価するエネルギー技術モデルの開発を行った. 本研究ではこのモデルを改良し, 炭素税の賦課や補助金の導入など幾つかの抑制対策の効果について具体的な評価を行うことを可能とした. このモデルの適用例として, わが国全体の2010年までの二酸化炭素排出量の見通しを推計し, 幾つかの政策シナリオの排出量削減効果について検討した. 本推計結果によれば, 2000年の二酸化炭素排出量を1990年排出量まで抑制するためには, 排出量1トンあたり3万円の炭素税の賦課が必要であった. また, この炭素税収をエネルギー消費技術に対する補助金として還元すれば, 必要となる炭素税率を3千円程度に引き下げることが可能であった.

This study has two main sections. First, we will review future global emission scenarios. This shows that the carbon intensity of fuels is a very important factor in determining CO2 emission rates. Second, we will show the relationship between the introduction of nuclear energy and other energy types to supply future energy demands. This will be di...

The Asian Pacific Integrated Model (AIM) is a large-scale model for scenario analyses of green-house gas (GHG) emissions and the impacts of global warming in the Asian Pacific region. The AIM comprises two main models — the AIM/emission model for predicting GHG emissions and the AIM/impact model for estimating the impacts of global warming — which...

The AIM/top-down model is a recursive general equilibrium model used to analyze the post-Kyoto scenarios presented by EMF16. Differences among scenarios mainly arise from the setting of emission trading. Japan's marginal cost is the highest among the Annex I countries except New Zealand, where a relatively high emission reduction is necessary, whil...