Author Name Variants
Fields of Specialization
Green growth, Climate change, Urban development
Externally Hosted Work
Last updated September 13, 2023
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).
Publication Search Results
Now showing 1 - 10 of 11
Publication(World Bank, Washington, DC, 2013-10) Hallegatte, Stephane ; Fay, Marianne ; Vogt-Schilb, AdrienGreen industrial policies can be defined as industrial policies with an environmental goal -- or more precisely, as sector-targeted policies that affect the economic production structure with the aim of generating environmental benefits. This paper provides a framework to assess their desirability depending on the effectiveness and political acceptability of price instruments. The main messages are the following. (i) Greening growth processes to the extent and with the speed needed cannot be done without industrial policies, even if prices can be adjusted to reflect environmental objectives. (ii) "Sunrise" green industrial policies are needed because they support the development of critical new technologies and sectors, bring down costs, and allow for reduced emissions in the short term even in the absence of carbon pricing. (iii) "Sunset" green industrial policies and trade policies may be needed in conjunction with safety nets to make carbon pricing politically or socially acceptable. They can help mitigate the impact of a carbon price on competitiveness and unemployment and smooth the transition by helping industries adjust to the new conditions. (iv) Green or not, industrial policy requires carefully navigating the twin dangers of market and governance failure. The viability of supported technologies and sectors is difficult to assess through a market-test given their dependence on continued environmental policies or pricing -- such as a carbon price. Particular attention must be paid to avoid potential unintended negative effects, such as rebound effects (especially if prices are inappropriate), misallocation of capital, or capture and rent-seeking behaviors.
Publication(World Bank, Washington, DC, 2014-03) Vogt-Schilb, Adrien ; Hallegatte, Stephane ; de Gouvello, ChristopheDecision makers facing abatement targets need to decide which abatement measures to implement, and in which order. This paper investigates the ability of marginal abatement cost (MAC) curves to inform this decision, reanalysing a MAC curve developed by the World Bank on Brazil. Misinterpreting MAC curves and focusing on short-term targets (e.g., for 2020) would lead to under-invest in expensive, long-to-implement and large-potential options, such as clean transportation infrastructure. Meeting short-term targets with marginal energy-efficiency improvements would lead to carbon-intensive lock-ins that make longer-term targets (e.g., for 2030 and beyond) impossible or too expensive to reach. Improvements to existing MAC curves are proposed, based on (1) enhanced data collection and reporting; (2) a simple optimization tool that accounts for constraints on implementation speeds; and (3) new graphical representations of MAC curves. Designing climate mitigation policies can be done through a pragmatic combination of two approaches. The synergy approach is based on MAC curves to identify the cheapest mitigation options and maximize co-benefits. The urgency approach considers the long-term objective (e.g., halving emissions by 2050) and works backward to identify actions that need to be implemented early, such as public support to clean infrastructure and zero-carbon technologies.
Publication(World Bank, Washington, DC, 2014-05) Hallegatte, StephaneThe welfare impact of a disaster does not only depend on the physical characteristics of the event or its direct impacts in terms of lost lives and assets. Welfare impacts also depend on the ability of the economy to cope, recover, and reconstruct and therefore to minimize aggregate consumption losses. This ability can be referred to as the macroeconomic resilience to natural disasters. Macroeconomic resilience has two components: instantaneous resilience, which is the ability to limit the magnitude of immediate production losses for a given amount of asset losses, and dynamic resilience, which is the ability to reconstruct and recover. Welfare impacts also depend on micro-economic resilience, which depends on the distribution of losses; on households' vulnerability, such as their pre-disaster income and ability to smooth shocks over time with savings, borrowing, and insurance, and on the social protection system, or the mechanisms for sharing risks across the population. The (economic) welfare disaster risk in a country can be reduced by reducing the exposure or vulnerability of people and assets (reducing asset losses), increasing macroeconomic resilience (reducing aggregate consumption losses for a given level of asset losses), or increasing microeconomic resilience (reducing welfare losses for a given level of aggregate consumption losses). The paper proposes rules of thumb to estimate macroeconomic and microeconomic resilience based on the relevant parameters in the economy. It also provides a toolbox of policies to increase macro- or micro-economic resilience and a list of indicators that can be used to build a resilience indicator.
Publication(World Bank, Washington, DC, 2014-05) Rozenberg, Julie ; Vogt-Schilb, Adrien ; Hallegatte, StephaneThis paper uses a Ramsey model with two types of capital to analyze the optimal transition to clean capital when polluting investment is irreversible. The cost of climate mitigation decomposes as a technical cost of using clean instead of polluting capital and a transition cost from the irreversibility of pre-existing polluting capital. With a carbon price, the transition cost can be limited by underutilizing polluting capital, at the expense of a loss in the value of polluting assets (stranded assets) and a drop in income. In contrast, policy instruments that focus on redirecting investments -- such as feebates or environmental standards -- prevent underutilization of existing capital, avoid stranded assets, and reduce short-term losses; but they reduce emissions more slowly and increase the intertemporal cost of the transition. The paper investigates inter- and intra-generational distributional impacts and the political acceptability of climate change mitigation policy instruments.
Publication(World Bank, Washington, DC, 2012-10) Hallegatte, StephaneThis 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.
A Cost Effective Solution to Reduce Disaster Losses in Developing Countries : Hydro-Meteorological Services, Early Warning, and Evacuation(World Bank, Washington, DC, 2012-05) Hallegatte, StéphaneIn Europe, it can be estimated that hydro-meteorological information and early warning systems save several hundreds of lives per year, avoid between 460 million and 2.7 billion Euros of disaster asset losses per year, and produce between 3.4 and 34 billion of additional benefits per year through the optimization of economic production in weather-sensitive sectors (agriculture, energy, etc.). The potential for similar benefits in the developing world is not only proportional to population, but also to increased hazard risk due to climate and geography, as well as increased exposure to weather due to the state of infrastructure. This analysis estimates that the potential benefits from upgrading to developed-country standards the hydro-meteorological information production and early warning capacity in all developing countries include: (i) between 300 million and 2 billion USD per year of avoided asset losses due to natural disasters; (ii) an average of 23,000 saved lives per year, which is valued between 700 million and 3.5 billion USD per year using the Copenhagen Consensus guidelines; and (iii) between 3 and 30 billion USD per year of additional economic benefits. The total benefits would reach between 4 and 36 billion USD per year. Because some of the most expensive components of early warning systems have already been built (e.g., earth observation satellites, global weather forecasts), these investments are relatively modest, estimated here around 1 billion US per year, reaching benefit-cost ratios between 4 and 36.
Publication(World Bank, Washington, DC, 2014-06) Kalra, Nidhi ; Hallegatte, Stephane ; Lempert, Robert ; Brown, Casey ; Fozzard, Adrian ; Gill, Stuart ; Shah, AnkurInvestment decision making is already difficult for any diverse group of actors with different priorities and views. But the presence of deep uncertainties linked to climate change and other future conditions further challenges decision making by questioning the robustness of all purportedly optimal solutions. While decision makers can continue to use the decision metrics they have used in the past (such as net present value), alternative methodologies can improve decision processes, especially those that lead with analysis and end in agreement on decisions. Such "Agree-on-Decision" methods start by stress-testing options under a wide range of plausible conditions, without requiring us to agree ex ante on which conditions are more or less likely, and against a set of objectives or success metrics, without requiring us to agree ex ante on how to aggregate or weight them. As a result, these methods are easier to apply to contexts of large uncertainty or disagreement on values and objectives. This inverted process promotes consensus around better decisions and can help in managing uncertainty. Analyses performed in this way let decision makers make the decision and inform them on (1) the conditions under which an option or project is vulnerable; (2) the tradeoffs between robustness and cost, or between various objectives; and (3) the flexibility of various options to respond to changes in the future. In doing so, they put decision makers back in the driver's seat. A growing set of case studies shows that these methods can be applied in real-world contexts and do not need to be more costly or complicated than traditional approaches. Finally, while this paper focuses on climate change, a better treatment of uncertainties and disagreement would in general improve decision making and development outcomes.
Publication(World Bank Group, Washington, DC, 2014-11) Hallegatte, Stephane ; Bangalore, Mook ; Bonzanigo, Laura ; Fay, Marianne ; Narloch, Ulf ; Rozenberg, Julie ; Vogt-Schilb, AdrienClimate change and climate policies will affect poverty reduction efforts through direct and immediate impacts on the poor and by affecting factors that condition poverty reduction, such as economic growth. This paper explores this relation between climate change and policies and poverty outcomes by examining three questions: the (static) impact on poor people's livelihood and well-being; the impact on the risk for non-poor individuals to fall into poverty; and the impact on the ability of poor people to escape poverty. The paper proposes four channels that determine household consumption and through which households may escape or fall into poverty (prices, assets, productivity, and opportunities). It then discusses whether and how these channels are affected by climate change and climate policies, focusing on the exposure, vulnerability, and ability to adapt of the poor (and those vulnerable to poverty). It reviews the existing literature and offers three major conclusions. First, climate change is likely to represent a major obstacle to a sustained eradication of poverty. Second, climate policies are compatible with poverty reduction provided that (i) poverty concerns are carefully taken into account in their design and (ii) they are accompanied by the appropriate set of social policies. Third, climate change does not modify how poverty policies should be designed, but it creates greater needs and more urgency. The scale issue is explained by the fact that climate will cause more frequent and more severe shocks; the urgency, by the need to exploit the window of opportunity given to us before climate impacts are likely to substantially increase.
Publication(World Bank, Washington, DC, 2015-07) Hallegatte, StephaneThe welfare impact of a disaster does not depend only on the physical characteristics of the event or its direct impacts in terms of lost lives and assets. Depending on the ability of the economy to cope, recover, and reconstruct, the reconstruction will be more or less difficult, and the welfare effects smaller or larger. This ability, which can be referred to as the macroeconomic resilience of the economy to natural disasters, is an important parameter to estimate the overall vulnerability of a population. Here, resilience is decomposed into two components: instantaneous resilience, which is the ability to limit the magnitude of the immediate loss of income for a given amount of capital losses, and dynamic resilience, which is the ability to reconstruct and recover quickly. The paper proposes a rule of thumb to estimate macroeconomic resilience, based on the interest rate (a higher interest rate decreases resilience and increases welfare losses), the reconstruction duration (a longer reconstruction duration increases welfare losses), and a “ripple-effect” factor that increases or decreases immediate losses (negative if enough idle resources are available to cope; positive if cross-sector and supply-chain issues impair the production of non-affected capital). An optimal risk management strategy is very likely to include measures to reduce direct impacts (disaster risk reduction actions) and measures to reduce indirect impacts (resilience building actions).
The Impacts of Climate Change on Poverty in 2030 and the Potential from Rapid, Inclusive, and Climate-Informed Development(World Bank, Washington, DC, 2015-11) Rozenberg, Julie ; Hallegatte, StephaneThe impacts of climate change on poverty depend on the magnitude of climate change, but also on demographic and socioeconomic trends. An analysis of hundreds of baseline scenarios for future economic development in the absence of climate change in 92 countries shows that the drivers of poverty eradication differ across countries. Two representative scenarios are selected from these hundreds. One scenario is optimistic regarding poverty and is labeled “prosperity;” the other scenario is pessimistic and labeled “poverty.” Results from sector analyses of climate change impacts—in agriculture, health, and natural disasters—are introduced in the two scenarios. By 2030, climate change is found to have a significant impact on poverty, especially through higher food prices and reduction of agricultural production in Africa and South Asia, and through health in all regions. But the magnitude of these impacts depends on development choices. In the prosperity scenario with rapid, inclusive, and climate-informed development, climate change increases poverty by between 3 million and 16 million in 2030. The increase in poverty reaches between 35 million and 122 million if development is delayed and less inclusive (the poverty scenario).