Person:
Hallegatte, Stéphane

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Green growth, Climate change, Urban development
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Last updated: February 13, 2024
Biography
Stéphane Hallegatte is a Senior Climate Change Adviser at the World Bank. He joined the World Bank in 2012 after 10 years of academic research in environmental economics and climate science for Météo-France, the Centre International de Recherche sur l’Environnement et le Développement, and Stanford University. His research interests include the economics of natural disasters and risk management, climate change adaptation, urban policy and economics, climate change mitigation, and green growth. Mr. Hallegatte was a lead author of the 5th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). He is the author of dozens of articles published in international journals in multiple disciplines and of several books, including Green Economy and the Crisis: 30 Proposals for a More Sustainable France , Risk Management: Lessons from the Storm Xynthia , and Natural Disasters and Climate Change: An Economic Perspective . He also co-led the World Bank reports Inclusive Green Growth: The Pathway to Sustainable Development , published in 2012 and Decarbonizing Development in 2015, and was member of the core writing team of the 2014 World Development Report Risk and Opportunity: Managing Risks for Development . Most recently, he led the World Bank reports Shock Waves: Managing the Impacts of Climate Change on Poverty , Unbreakable: Building the Resilience of the Poor in the Face of Natural Disasters , and Lifelines: the Resilient Infrastructure Opportunity. He was the team leader for the World Bank Group Climate Change Action Plan, a large internal coordination exercise to determine and explain how the Group will support countries in their implementation of the Paris Agreement. Mr. Hallegatte holds engineering degrees from the Ecole Polytechnique (Paris) and the Ecole Nationale de la Météorologie (Toulouse), a master's degree in meteorology and climatology from the Université Paul Sabatier (Toulouse) and a Ph.D in economics from the Ecole des Hautes Etudes en Sciences Sociales (Paris).
Citations 2007 Scopus

Publication Search Results

Now showing 1 - 10 of 74
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Strengthening New Infrastructure Assets: A Cost-Benefit Analysis

2019-06, Nicolas, Claire, Hallegatte, Stephane, Fox, Charles, Rozenberg, Julie, Rentschler, Jun

This paper explores the benefits and the costs of strengthening infrastructure assets to make them more resilient, reducing the repair costs and infrastructure disruptions caused by natural hazards. Strengthening infrastructure assets in low- and middle-income countries would increase investment needs in power, transport, and water and sanitation by between $11 billion and $65 billion a year, i.e. 3 percent of baseline infrastructure investment needs. The uncertainty pertaining to the costs and benefits of infrastructure resilience makes it difficult to provide a single estimate for the benefit-cost ratio of strengthening exposed infrastructure assets. To manage this uncertainty, this paper explores the benefit-cost ratio in 3,000 scenarios, combining uncertainties in all parameters of the analysis. The benefit-cost ratio is higher than 1 in 96 percent of the scenarios, larger than 2 in 77 percent of them, and higher than 4 in half of them. The net present value of these investments over the lifetime of new infrastructure assets -- or, equivalently, the cost of inaction -- exceeds $2 trillion in 75 percent of the scenarios and $4.2 trillion in half of them. Moreover, climate change makes the strengthening of infrastructure assets even more important, doubling the median benefit-cost ratio.

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Carbon Price Efficiency : Lock-in and Path Dependence in Urban Forms and Transport Infrastructure

2014-06, Avner, Paolo, Rentschler, Jun, Hallegatte, Stéphane, Avner, Paolo

This paper investigates the effect of carbon or gasoline taxes on commuting-related CO2 emissions in an urban context. To assess the impact of public transport on the efficiency of the tax, the paper investigates two exogenous scenarios using a dynamic urban model (NEDUM-2D) calibrated for the urban area of Paris: (i) a scenario with the current dense public transport infrastructure, and (ii) a scenario without. It is shown that the price elasticity of CO2 emissions is twice as high in the short run if public transport options exist. Reducing commuting-related emissions thus requires lower (and more acceptable) tax levels in the presence of dense public transportation. If the goal of a carbon or gasoline tax is to change behaviors and reduce energy consumption and CO2 emissions (not to raise revenues), then there is an incentive to increase the price elasticity through complementary policies such as public transport development. The emission elasticity also depends on the baseline scenario and is larger when population growth and income growth are high. In the longer run, elasticities are higher and similar in the scenarios with and without public transport, because of larger urban reconfiguration in the latter scenario. These results are policy relevant, especially for fast-growing cities in developing countries. Even for cities where emission reductions are not a priority today, there is an option value attached to a dense public transport network, since it makes it possible to reduce emissions at a lower cost in the future.

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An Exploration of the Link between Development, Economic Growth, and Natural Risk

2012-10, Hallegatte, Stephane

This paper investigates the link between development, economic growth, and the economic losses from natural disasters in a general analytical framework, with an application to hurricane flood risks in New Orleans. It concludes that where capital accumulates through increased density of capital at risk in a given area, and the costs of protection therefore increase more slowly than capital at risk, (i) protection improves over time and the probability of disaster occurrence decreases; (ii) capital at risk -- and thus economic losses in case of disaster -- increases faster than economic growth; (iii) increased risk-taking reinforces economic growth. In this context, average annual losses from disasters grow with income, and they grow faster than income at low levels of development and slower than income at high levels of development. These findings are robust to a broad range of modeling choices and parameter values, and to the inclusion of risk aversion. They show that risk-taking is both a driver and a consequence of economic development, and that the world is very likely to experience fewer but more costly disasters in the future. It is therefore critical to increase economic resilience through the development of stronger recovery and reconstruction support instruments.

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Climate Policy and Inequality in Urban Areas: Beyond Incomes

2022-09, Liotta, Charlotte, Avner, Paolo, Viguié, Vincent, Selod, Harris, Hallegatte, Stephane, Avner, Paolo

Opposition to climate policies seems to arise, at least partly, from their effects on inequality. However, so far, the impact of climate policies on inequality has mainly been studied through the lens of income inequality, and their spatial dimension is poorly understood. This paper, using Cape Town, South Africa, as a case study, investigates the impact of a fuel tax on both spatial and income inequalities. It uses a model derived from the standard urban economics land use model, accounting for four income classes and four housing types. This modeling framework allows decomposing the impacts of the tax by income class, housing type, and housing location. The analysis also decomposes the impacts of the tax over different timeframes, assuming that households and developers progressively adapt to the tax. The findings reveal strong evidence that in the short term, there are both income and spatial inequalities, with households being more negatively impacted by the fuel tax if they earn low incomes or live far from employment centers. In the medium and long term, these inequalities persist: the poorest households, living in informal settlements or subsidized housing, have few or no ways to adapt to changes in fuel prices by changing housing type, adjusting their dwelling sizes or locations, or shifting transportation modes. Low-income households living in formal housing also remain impacted by the tax over the long term due to complex effects driven by the competition with richer households on the housing market. Complementary policies promoting a functioning labor market that allows people to change jobs easily, affordable public transportation, or subsidies helping low-income households to rent houses closer to employment centers will be key to enable the social acceptability of climate policies.

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Natural Disasters, Poverty and Inequality: New Metrics for Fairer Policies

2021-10-28, Hallegatte, Stephane

Conventional risk assessments underestimate the human and macroeconomic costs of disasters, leading to inefficient risk management strategies. This happens because conventional assessments focus on asset losses, neglecting important relationships between vulnerability and development. When affected by a hazard, poor households take longer to recover from disasters and are more likely to face long-term consequences. Forced to manage trade-offs between essential consumption and reconstruction, these households are more likely to face persistent health or education costs. This chapter proposes a review of existing research into the natural disaster-poverty-inequality nexus and the various metrics that can be used to measure disaster impacts, such as recovery times, economic (income or consumption) losses, poverty incidence, inequality, and welfare or well-being losses. Each of these metrics provides a different perspective on disaster costs and suggest different spatial and sectoral priorities for action. Focusing on the concepts of well-being losses and socioeconomic resilience, this chapter shows how more comprehensive accounting of disaster impacts can better inform disaster risk management and climate change adaptation strategies and support their integration into development and poverty-reduction policies.

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The Economics of Natural Disasters : Concepts and Methods

2010-12-01, Hallegatte, Stephane

Large-scale disasters regularly affect societies over the globe, causing large destruction and damage. After each of these events, media, insurance companies, and international institu-tions publish numerous assessments of the "cost of the disaster." However these assessments are based on different methodologies and approaches, and they often reach different results. Besides methodological differences, these discrepancies are due to the multi-dimensionality in disaster impacts and their large redistributive effects, which make it unclear what is included in the estimates. But most importantly, the purpose of these assessments is rarely specified, although different purposes correspond to different perimeters of analysis and different definitions of what a cost is. To clarify this situation, this paper proposes a definition of the cost of a disaster, and emphasizes the most important mechanisms that explain and determine this cost. It does so by first explaining why the direct economic cost, that is, the value of what has been damaged or destroyed by the disaster, is not a sufficient indicator of disaster seriousness and why estimating indirect losses is crucial to assess the consequences on welfare. The paper describes the main indirect consequences of a disaster and the following reconstruction phase, and discusses the economic mechanisms at play. It proposes a review of available methodologies to assess indirect economic consequences, illustrated with examples from the literature. Finally, it highlights the need for a better understanding of the economics of natural disasters and suggests a few promising areas for research on this topic.

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Socioeconomic Resilience in Sri Lanka: Natural Disaster Poverty and Wellbeing Impact Assessment

2019-09, Walsh, Brian, Hallegatte, Stephane

Traditional risk assessments use asset losses as the main metric to measure the severity of a disaster. This paper proposes an expanded risk assessment based on a framework that adds socioeconomic resilience and uses wellbeing losses as the main measure of disaster severity. Using an agent-based model that represents explicitly the recovery and reconstruction process at the household level, this risk assessment provides new insights into disaster risks in Sri Lanka. The analysis indicates that regular flooding events can move tens of thousands of Sri Lankans into transient poverty at once, hindering the country's recent progress on poverty eradication and shared prosperity. As metrics of disaster impacts, poverty incidence and well-being losses facilitate quantification of the benefits of interventions like rapid post-disaster support and adaptive social protection systems. Such investments efficiently reduce wellbeing losses by making exposed and vulnerable populations more resilient. Nationally and on average, the bottom income quintile suffers only 7 percent of the total asset losses but 32 percent of the total wellbeing losses. Average annual wellbeing losses due to fluvial flooding in Sri Lanka are estimated at US$119 million per year, more than double the asset losses of US$78 million. Asset losses are reported to be highly concentrated in Colombo district, and wellbeing losses are more widely distributed throughout the country. Finally, the paper applies the socioeconomic resilience framework to a cost-benefit analysis of prospective adaptive social protection systems, based on enrollment in Samurdhi, the main social support system in Sri Lanka.

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Higher Losses and Slower Development in the Absence of Disaster Risk Management Investments

2016-04, Hallegatte, Stephane, Jouanjean, Marie-Agnes

Global economic losses from natural disasters continue to increase. Yet, investments in disaster risk management are not universal, as they are traditionally seen as in competition with other development and economic priorities. The multitude of benefits from disaster risk management investments are not traditionally accounted for in cost-benefit analyses. This paper contributes to this discussion by highlighting the multiple benefits from disaster risk management investments, focusing on the avoided losses when a disaster occurs, but also on the impacts on economic development even before a disaster strikes. The paper's main message is that disaster risk management investments can provide two dividends: reduced losses when a disaster strikes, and a shift of investment strategies and perhaps even an increase in investment value that would benefit the economy even before a disaster strikes. Providing evidence to policy makers and investors about the existence of both types of dividends can provide a narrative reconciling short-term and long-term objectives, thereby improving the acceptability and feasibility of disaster risk management investments.

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A Note on the Economic Cost of Climate Change and the Rationale to Limit it Below 2°C

2010-01, Hallegatte, Stephane, Hourcade, Jean-Charles

This note highlights a major reason to limit climate change to the lowest possible levels. This reason follows from the large increase in uncertainty associated with high levels of warming. This uncertainty arises from three sources: the change in climate itself, the change s impacts at the sector level, and their macroeconomic costs. First, the greater the difference between the future climate and the current one, the more difficult it is to predict how local climates will evolve, making it more difficult to anticipate adaptation actions. Second, the adaptive capacity of various economic sectors can already be observed for limited warming, but is largely unknown for larger changes. The larger the change in climate, therefore, the more uncertain is the final impact on economic sectors. Third, economic systems can efficiently cope with sectoral losses, but macroeconomic-level adaptive capacity is difficult to assess, especially when it involves more than marginal economic changes and when structural economic shifts are required. In particular, these shifts are difficult to model and involve thresholds beyond which the total macroeconomic cost would rise rapidly. The existence of such thresholds is supported by past experiences, including economic disruptions caused by natural disasters, observed difficulties funding needed infrastructure, and regional crises due to rapid economic shifts induced by new technologies or globalization. As a consequence, larger warming is associated with higher cost, but also with larger uncertainty about the cost. Because this uncertainty translates into risks and makes it more difficult to implement adaptation strategies, it represents an additional motive to mitigate climate change.

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From Growth to Green Growth : A Framework

2011-11-01, Hallegatte, Stephane, Fay, Marianne

Green growth is about making growth processes resource-efficient, cleaner and more resilient without necessarily slowing them. This paper aims at clarifying these concepts in an analytical framework and at proposing foundations for green growth. The green growth approach proposed here is based on (1) focusing on what needs to happen over the next 5-10 years before the world gets locked into patterns that would be prohibitively expensive and complex to modify and (2) reconciling the short and the long term, by offsetting short-term costs and maximizing synergies and economic co-benefits. This, in turn, increases the social and political acceptability of environmental policies. This framework identifies channels through which green policies can potentially contribute to economic growth. However, only detailed country- and context-specific analyses for each of these channels could reach firm conclusion regarding their actual impact on growth. Finally, the paper discusses the policies that can be implemented to capture these co-benefits and environmental benefits. Since green growth policies pursue a variety of goals, they are best served by a combination of instruments: price-based policies are important but are only one component in a policy tool-box that can also include norms and regulation, public production and direct investment, information creation and dissemination, education and moral suasion, or industrial and innovation policies.