Improved decision making for people and the planet: an assessment of the climate and health co-benefits of Tokyo’s climate action plans

Title of PhD project

Improved decision making for people and the planet: an assessment of the climate and health co-benefits of Tokyo’s climate action plans

Supervisory team

Nagasaki University

Lead: Lina Madaniyazi (


Sarah Whitmee (Faculty of Epidemiology and Population Health,

James Milner (                                                           

Brief description of project


Urgent cuts in greenhouse gas (GHG) emissions are needed to limit future global temperature increases to 1.5°C above pre-industrial levels (or failing that, to well under 2°C, which is the goal of the Paris Agreement). The challenge of achieving net zero emissions by 2050 at the latest, also presents a unique opportunity to drive transformative changes in all sectors of society. These changes will bring major benefits for health, both by reducing the health risks of climate change and by capitalising on the multiple ancillary benefits to human health, and development (co-benefits) from well-designed actions to cut GHG emissions. Modelling studies show that many millions of premature deaths could be prevented and GHG emissions greatly reduced by phasing out fossil fuels (thus reducing air pollution), encouraging active travel and public transport use and shifting to more sustainable and healthier diets (Whitmee et al 2021).

Cities account for up to 70% of global emissions, 80% of global gross domestic product (GDP) and 55% of the global population. Two-thirds of the global population will live in cities by 2050, meaning that effective climate action by cities is vital to reach net zero. Climate action by cities with populations over 100,000 could deliver an estimated 40% of the global emissions reductions needed to limit warming to 1.5°C. Focusing efforts on key mitigation actions across energy, buildings, transport and waste, could enable cities to achieve 90-100% of the emissions reductions they need to work within a 1.5°C pathway (C40 and ARUP, 2020). In addition, by taking timely actions to cut emissions and reduce vulnerabilities, cities can gain multiple co-benefits from climate action.

Despite this potential to reduce emissions, cities face a number of barriers to delivering effective climate action. Cities have multiple competing priorities, and climate action has often been perceived to come at the cost of other goals such as economic growth and inequality reduction. Being able to evaluate competing policies and their health co-benefits can be vital to help make the case for climate action to key decision-makers and other city stakeholders, such as local companies, catalysing them to implement and embed climate actions while improving the health and wellbeing of their residents.

As a G7 nation, Japan needs to further accelerate its low-carbon transition to achieve recent commitments to fully or predominantly decarbonised electricity by 2035 and to end fossil fuel subsidies by 2025. While recent pledges have been a step forward, Climate Action Tracker currently rates Japan’s latest Nationally Determined Contributions as “Insufficient”, meaning it still falls short of the more than 60% emission reduction that is necessary to minimise global temperature rises to 1.5°C (Climate Action Tracker, 2022).

At the city level, Tokyo has developed the Zero Emission Tokyo Strategy, a Climate Action Plan that aims to achieve net zero CO2 emissions by 2050. The plan highlights six key sectors with 14 policies to help Tokyo achieve net zero emissions, including actions in energy, urban infrastructure for buildings, urban infrastructure for transport, resource/industrial sector and engagement & inclusion. Japan also has significant and increasing exposure to the impacts of climate change, and therefore any actions must take place alongside measures to adapt and promote resilience to climate change. Quantifying and comparing the mitigation potential and health co-benefits of the proposed actions could help prioritise actions and smooth implementation while delivering significant benefits for Tokyo’s residents.

The Project

This studentship will evaluate the health co-benefits of Tokyo's policies relating to climate mitigation, including the Zero Emission Tokyo Strategy policy. It will use transdisciplinary approaches to model climate mitigation and health outcomes to generate evidence to inform policy selection and decision making in a city at the forefront of climate action.

The student will:

(1) use programme theory and tools (CRAFT) developed from the Complex Urban Systems for Sustainability and Health (CUSSH) project (Moore et al 2021; Symonds et al 2021) and apply this to create a conceptual framework and models for Tokyo, to assess the impact of Tokyo’s policies on climate mitigation, population health, health inequalities and socioeconomic and environmental parameters for policy packages under consideration.

(2) Develop a detailed inventory, including descriptions and interactions, of current and planned policies/policy objectives for Tokyo’s Net Zero Plans in the housing, energy, food and transport sectors.

(3) Identify suitable data with which to parameterise a model of the effects of these policies on population health, health equity and greenhouse gas emissions.

(4)  Using the previously developed CRAFT tool, build models of Tokyo’s population to assess the cross-sector impact of policies on population health, health inequalities and GHG reductions across the energy, housing, transport and food sectors.

(5) Inform and evaluate Tokyo’s policies (actual and potential) aimed at the transformation of to a healthy, Net Zero future. Policies will be evaluated against their potential impacts on population health and GHG emissions.

(6) Compare and contrast findings with those from cities in other G7 countries (e.g. London) to share lessons and test model sensitivity between settings and against other methods for assessing policy impacts to understand the role of model choice and contextual factors in influencing both outcomes and policy decision making.

The project will build on existing methods developed at LSHTM, including CRAFT (Symonds et al 2021) which has been used to perform an assessment of climate actions across different sectors for London, and a synthetic population model currently in development by James Milner and colleagues.  The project will entail generating individual members of a large synthetic, geographically-stratified population that is representative of the true population of Tokyo in terms of age, sex, socio-economic structure, environmental and health behaviours, GHG emissions and health (mortality and morbidity risks also related to age, sex and socio-economic characteristics). The characteristics of the population will be derived from published evidence from population surveys and routine statistics coupled with sectoral data on housing, transport patterns and dietary data from routine surveys including Statistics Bureau of Japan, The National Nutrition Survey, and Inter-Regional Travel Survey.

Expected outputs

  • Identification of data on health co-benefits and pathways in Japan
  • Synthetic population model for Tokyo
  • Integrated estimates of the impacts on GHG emissions and health of cross-sectoral policy options of Tokyo’s climate mitigation policies including the Zero Emission Strategy

Expected outcomes

  • Improved understanding of the pathways and effects for health of climate mitigation policy options
  • Decision making on climate action in Tokyo informed by provision of modelling data on multiple impacts and policy packages

Wider links

The project will both inform and be informed by the Pathfinder Initiative based at LSHTM.  Pathfinder is a global initiative which aims to catalyse and support successful action on climate mitigation with a focus on measured co-benefits for health. The first phase of the Pathfinder Initiative synthesised evidence on actions with the largest potential co-benefits, including energy, transport and agriculture/ food sectors. The Pathfinder Initiative has established partnerships with C40 cities, CDP, the Sustainable Development Solutions Network (SDSN) and the OECD – the student will be able to capitalise on these links to engage with organisations at the forefront of city level action on climate change. The second phase of the project (expected to start in spring 2023) will focus on three key areas where progress is needed: evidence for action, monitoring and evaluating progress; and capacity strengthening. First, machine learning techniques will be used to bring together relevant evidence and make it accessible to actors using a living evidence map. Second, a coalition of research, enabling and implementing partners will be set up to galvanise the implementation of informed actions and their evaluation. Third, a community of practice will be brought together for sharing of knowledge and tools. The key goals of the project are to identify and deliver context-specific evidence on health co-benefits, and to strengthen global capacity to implement and evaluate climate mitigation actions that will promote human health.

Key References

1. Whitmee S, Green R, Phumaphi J, Clark H, Haines A (2021). Bridging the evidence gap to achieve a healthy, net zero future. The Lancet, 398, 1551–1553.

2. C40 & ARUP. Deadline 2020 How Cities Will Get the Job Done. 59

3. Climate Action Tracker: Country Report Japan (2022)

4. Moore, G, Michie, S, Anderson, J, Belesova, K, Crane, M, Deloly, C, Dimitroulopoulou C, Gitau H, Hale J, Lloyd SJ, Mberu B, Muindi K, Niu Y, Pineo H, Pluchinotta I, Prasad A, Roue-Le Gall A, Shrubsole C, Turcu C, Tsoulou I, Wilkinson P, Zhou K, Zimmermann N, Davies M, Osrin D (2021). Developing a programme theory for a transdisciplinary research collaboration: Complex Urban Systems for Sustainability and Health. Wellcome Open Research, 6, 35.

5. Symonds P, Milner J, Mohajeri N, Alpin J, Hale J, Lloyd SJ, Fremont H, Younkin S, Shrubsole C, Robertson L, Taylor J, Zimmermann N, Wilkinson P, Davies M (2021). A tool for assessing the climate change mitigation and health impacts of environmental policies: the Cities Rapid Assessment Framework for Transformation (CRAFT). Wellcome Open Research, 5, 269.

The role of LSHTM and NU in this collaborative project

The student will be based mostly at Nagasaki University for policy identification and data collection but will spend at least 3 months at LSHTM for training in modelling and supervisory inputs, including broadening of knowledge on climate mitigation and health. Full supervisory meetings will be conducted remotely every month and advisory meetings every 3 months.

Advisory committee members will be recruited from Pathfinder partner organisations (e.g C40, CDP) to provide support on policy relevance and access to policy makers at the city level in Tokyo and from the wider NU team to inform and advise on access to relevant datasets.

The project will benefit from engagement with the larger Pathfinder Initiative (including attendance at Lancet Scientific Commission meetings) and with the Centre on Planetary Health and Climate Change (WHO Collaborating Centre on Climate Change) at LSHTM.

Particular prior educational requirements for a student undertaking this project

The candidate should have a Master’s degree in environmental epidemiology, global public health or related subject in planetary health

Training or experience in handling large datasets and conducting quantitative analysis, experience of using R programming language or similar programming language is desirable.

An interest in global environmental health and/or climate change research is desirable.

Verbal and written proficiency in Japanese.

Skills we expect a student to develop/acquire whilst pursuing this project

  • Interdisciplinary research skills, specifically between the fields of environmental change and human health
  • Experience in modelling and advanced statistical analysis in R and working with large datasets on environment and health
  • A focus on producing policy relevant research and working at the interface between academia and practice in climate change mitigation action
  • Project management
  • Critical review skills of data from diverse sources and ability to synthesise and formulate new hypotheses