JU, Yiyi



Affiliated organization, Waseda Institute for Advanced Study

Job title

Assistant Professor(non-tenure-track)

Concurrent Post 【 display / non-display

  • Faculty of Social Sciences   School of Social Sciences

Education 【 display / non-display

  • 2016.10

    Nagoya University   Graduate School of International Development   Doctor of Philosophy (International Development)  

Research Experience 【 display / non-display

  • 2021.04

    Waseda University   Institue for Advanced Study   Assistant professor

  • 2020.11

    The University of Tokyo

  • 2019.10

    The University of Tokyo

Professional Memberships 【 display / non-display

  • 2017.04

    Pan Pacific Association of Input-Output Studies (PAPAIOS)

  • 2017.04

    Society for Environmental Economics and Policy Studies (SEEPS)


Research Areas 【 display / non-display

  • Environmental policy and social systems

Research Interests 【 display / non-display

  • Industrial decarbonization

  • Energy-economic and integrated assessment models

  • Climate policy instruments

Papers 【 display / non-display

  • An open-source tool for visualization of climate mitigation scenarios: Mipplot

    Yiyi Ju, Masahiro Sugiyama, Diego Silva Herran, Jiayang Wang, Akimitsu Inoue

    Environmental Modelling & Software   139   105001 - 105001  2021.05


  • Industrial decarbonization under Japan’s national mitigation scenarios: a multi-model analysis

    Yiyi Ju, Masahiro Sugiyama, Etsushi Kato, Yuhji Matsuo, Ken Oshiro, Diego Silva Herran

    Sustainability Science    2021

     View Summary

    © 2021, The Author(s). Energy-intensive industries are difficult to decarbonize. They present a major challenge to the emerging countries that are currently in the midst of rapid industrialization and urbanization. This is also applicable to Japan, a developed economy, which retains a large presence in heavy industries compared to other developed economies. In this paper, the results obtained from four energy-economic and integrated assessment models were utilized to explore climate mitigation scenarios of Japan’s industries by 2050. The results reveal that: (i) Japan’s share of emissions from industries may increase by 2050, highlighting the difficulties in achieving industrial decarbonization under the prevailing industrial policies; (ii) the emission reduction in steelmaking will play a key role, which can be achieved by the implementation of carbon capture and expansion of hydrogen technologies after 2040; (iii) even under mitigation scenarios, electrification and the use of biomass use in Japan’s industries will continue to be limited in 2050, suggesting a low possibility of large-scale fuel switching or end-use decarbonization. After stocktaking of the current industry-sector modeling in integrated assessment models, we found that such limited uptake of cleaner fuels in the results may be related to the limited interests of both participating models and industry stakeholders in Japan, specifically the interests on the technologies that are still at the early stage of development but with high reduction potential. It is crucial to upgrade research and development activities to enable future industry-sector mitigation as well as to improve modeling capabilities of energy end-use technologies in integrated assessment models.


  • Revealing the impact of a projected emission trading scheme on the production technology upgrading in the cement industry in China: An LCA-RCOT model

    Yiyi Ju, Kiyoshi Fujikawa

    Resources, Conservation and Recycling: X   4  2019.12

     View Summary

    © 2019 The Author(s) The cement industry in China has been conducting overcapacity elimination through technology upgrading in the past years. Most of the overcapacity elimination policies are in the form of administrative and regulative approaches. However, the cost of overcapacity elimination by implementing command-and-control policies will be increasingly higher, at the same time, the orientation of such technology upgrading remains unknown. Such contradiction creates the necessities to reveal the impact of other policy instruments on the technology upgrading in the cement industry, as well as to clarify the optimal output allocation among all alternative technology choices. In this paper, an LCA-RCOT model (Life Cycle Assessment and Rectangular Choices Of Technologies) is established to provide such optimal technology combination with the constraints from a projected emission trading scheme (ETS). The results show that under an ETS cap with a target of 5% reduction of emission, 10% of subsidy allowances, and one-way linking with another ETS with higher average market price, the optimal solution suggest that 114.5 billion USD of total output in the cement sector should be produced by small dry kilns, while 102.5 billion USD by large dry kilns. In all feasible solutions, the optimal technology combination may shift to fewer shaft kilns and more dry kilns. In the long run, the climate policy instrument, ETS, may promote the upgrading of production technology by decomposing the total emission mitigation costs to the factor inputs of each cement producer.


  • EMF 35 JMIP study for Japan’s long-term climate and energy policy: scenario designs and key findings

    Masahiro Sugiyama, Shinichiro Fujimori, Kenichi Wada, Ken Oshiro, Etsushi Kato, Ryoichi Komiyama, Diego Silva Herran, Yuhji Matsuo, Hiroto Shiraki, Yiyi Ju

    Sustainability Science   16 ( 2 ) 355 - 374  2021

     View Summary

    © 2021, The Author(s). In June, 2019, Japan submitted its mid-century strategy to the United Nations Framework Convention on Climate Change and pledged 80% emissions cuts by 2050. The strategy has not gone through a systematic analysis, however. The present study, Stanford Energy Modeling Forum (EMF) 35 Japan Model Intercomparison project (JMIP), employs five energy-economic and integrated assessment models to evaluate the nationally determined contribution and mid-century strategy of Japan. EMF 35 JMIP conducts a suite of sensitivity analyses on dimensions including emissions constraints, technology availability, and demand projections. The results confirm that Japan needs to deploy all of its mitigation strategies at a substantial scale, including energy efficiency, electricity decarbonization, and end-use electrification. Moreover, they suggest that with the absence of structural changes in the economy, heavy industries will be one of the hardest to decarbonize. Partitioning of the sum of squares based on a two-way analysis of variance (ANOVA) reconfirms that mitigation strategies, such as energy efficiency and electrification, are fairly robust across models and scenarios, but that the cost metrics are uncertain. There is a wide gap of policy strength and breadth between the current policy instruments and those suggested by the models. Japan should strengthen its climate action in all aspects of society and economy to achieve its long-term target.


  • アジアの脱炭素化のためのエネルギー・モデル連携に向けて

    杉山昌広, 居乂義, 滕飛, Yong-Gun Kim, 蘇斌

    環境経済・政策研究   13 ( 2 ) 85 - 88  2020.09

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Books and Other Publications 【 display / non-display

  • China’s Carbon-Energy Policy and Asia’s Energy Transition Carbon Leakage, Relocation and Halos

    Edited By Akihisa Mori( Part: Joint author, Chapter 11., Generating or receiving carbon leakages?: An examination of China in Asia Le Tuyet Vo and Yiyi Ju)

    Routledge  2021.12

Research Projects 【 display / non-display

  • 石炭投融資撤退による環境・経済・経営持続性への移行:アジアの事例分析


    Project Year :


    森 晶寿


Syllabus 【 display / non-display