Publication:
Do We Need A Zero Pure Time Preference or the Risk of Climate Catastrophes to Justify A 2°C Global Warming Target?

Loading...
Thumbnail Image
Files in English
English PDF (676.68 KB)
162 downloads
English Text (50.52 KB)
56 downloads
Date
2010-07-01
ISSN
Published
2010-07-01
Editor(s)
Abstract
This paper confronts the wide political support for the 2C objective of global increase in temperature, reaffirmed in Copenhagen, with the consistent set of hypotheses on which it relies. It explains why neither an almost zero pure time preference nor concerns about catastrophic damages in case of uncontrolled global warming are prerequisites for policy decisions preserving the possibility of meeting a 2C target. It rests on an optimal stochastic control model balancing the costs and benefits of climate policies resolved sequentially in order to account for the arrival of new information (the RESPONSE model). This model describes the optimal abatement pathways for 2,304 worldviews, combining hypotheses about growth rates, baseline emissions, abatement costs, pure time preference, damages, and climate sensitivity. It shows that 26 percent of the worldviews selecting the 2C target are not characterized by one of the extreme assumptions about pure time preference or climate change damages.
Link to Data Set
Citation
Dumas, P.; Hourcade, J. C.; Fabert, B. Perrissin. 2010. Do We Need A Zero Pure Time Preference or the Risk of Climate Catastrophes to Justify A 2°C Global Warming Target?. Policy Research working paper ; no. WPS 5392. © World Bank. http://hdl.handle.net/10986/3876 License: CC BY 3.0 IGO.
Associated URLs
Associated content
Report Series
Report Series
Other publications in this report series
  • Publication
    The Future of Poverty
    (Washington, DC: World Bank, 2025-07-15) Fajardo-Gonzalez, Johanna; Nguyen, Minh C.; Corral, Paul
    Climate change is increasingly acknowledged as a critical issue with far-reaching socioeconomic implications that extend well beyond environmental concerns. Among the most pressing challenges is its impact on global poverty. This paper projects the potential impacts of unmitigated climate change on global poverty rates between 2023 and 2050. Building on a study that provided a detailed analysis of how temperature changes affect economic productivity, this paper integrates those findings with binned data from 217 countries, sourced from the World Bank’s Poverty and Inequality Platform. By simulating poverty rates and the number of poor under two climate change scenarios, the paper uncovers some alarming trends. One of the primary findings is that the number of people living in extreme poverty worldwide could be nearly doubled due to climate change. In all scenarios, Sub-Saharan Africa is projected to bear the brunt, contributing the largest number of poor people, with estimates ranging between 40.5 million and 73.5 million by 2050. Another significant finding is the disproportionate impact of inequality on poverty. Even small increases in inequality can lead to substantial rises in poverty levels. For instance, if every country’s Gini coefficient increases by just 1 percent between 2022 and 2050, an additional 8.8 million people could be pushed below the international poverty line by 2050. In a more extreme scenario, where every country’s Gini coefficient increases by 10 percent between 2022 and 2050, the number of people falling into poverty could rise by an additional 148.8 million relative to the baseline scenario. These findings underscore the urgent need for comprehensive climate policies that not only mitigate environmental impacts but also address socioeconomic vulnerabilities.
  • Publication
    Exports, Labor Markets, and the Environment
    (Washington, DC: World Bank, 2025-07-14) Góes, Carlos; Conceição, Otavio; Lara Ibarra, Gabriel; Lopez-Acevedo, Gladys
    What is the environmental impact of exports? Focusing on 2000–20, this paper combines customs, administrative, and census microdata to estimate employment elasticities with respect to exports. The findings show that municipalities that faced increased exports experienced faster growth in formal employment. The elasticities were 0.25 on impact, peaked at 0.4, and remained positive and significant even 10 years after the shock, pointing to a long and protracted labor market adjustment. In the long run, informal employment responds negatively to export shocks. Using a granular taxonomy for economic activities based on their environmental impact, the paper documents that environmentally risky activities have a larger share of employment than environmentally sustainable ones, and that the relationship between these activities and exports is nuanced. Over the short run, environmentally risky employment responds more strongly to exports relative to environmentally sustainable employment. However, over the long run, this pattern reverses, as the impact of exports on environmentally sustainable employment is more persistent.
  • Publication
    The Macroeconomic Implications of Climate Change Impacts and Adaptation Options
    (Washington, DC: World Bank, 2025-05-29) Abalo, Kodzovi; Boehlert, Brent; Bui, Thanh; Burns, Andrew; Castillo, Diego; Chewpreecha, Unnada; Haider, Alexander; Hallegatte, Stephane; Jooste, Charl; McIsaac, Florent; Ruberl, Heather; Smet, Kim; Strzepek, Ken
    Estimating the macroeconomic implications of climate change impacts and adaptation options is a topic of intense research. This paper presents a framework in the World Bank's macrostructural model to assess climate-related damages. This approach has been used in many Country Climate and Development Reports, a World Bank diagnostic that identifies priorities to ensure continued development in spite of climate change and climate policy objectives. The methodology captures a set of impact channels through which climate change affects the economy by (1) connecting a set of biophysical models to the macroeconomic model and (2) exploring a set of development and climate scenarios. The paper summarizes the results for five countries, highlighting the sources and magnitudes of their vulnerability --- with estimated gross domestic product losses in 2050 exceeding 10 percent of gross domestic product in some countries and scenarios, although only a small set of impact channels is included. The paper also presents estimates of the macroeconomic gains from sector-level adaptation interventions, considering their upfront costs and avoided climate impacts and finding significant net gross domestic product gains from adaptation opportunities identified in the Country Climate and Development Reports. Finally, the paper discusses the limits of current modeling approaches, and their complementarity with empirical approaches based on historical data series. The integrated modeling approach proposed in this paper can inform policymakers as they make proactive decisions on climate change adaptation and resilience.
  • Publication
    The Asymmetric Bank Distress Amplifier of Recessions
    (Washington, DC: World Bank, 2025-07-11) Kim, Dohan
    One defining feature of financial crises, evident in U.S. and international data, is asymmetric bank distress—concentrated losses on a subset of banks. This paper proposes a model in which shocks to borrowers’ productivity dispersion lead to asymmetric bank losses. The framework exhibits a “bank distress amplifier,” exacerbating economic downturns by causing costly bank failures and raising uncertainty about the solvency of banks, thereby pushing banks to deleverage. Quantitative analysis shows that the bank distress amplifier doubles investment decline and increases the spread by 2.5 times during the Great Recession compared to a standard financial accelerator model. The mechanism helps explain how a seemingly small shock can sometimes trigger a large crisis.
  • Publication
    Impact of Heat Waves on Learning Outcomes and the Role of Conditional Cash Transfers
    (Washington, DC: World Bank, 2025-07-14) Miranda, Juan José; Contreras, Cesar
    This paper evaluates the impact of higher temperatures on learning outcomes in Peru. The results suggest that 1 degree above 20°C is equivalent to 7 and 6 percent of a standard deviation of what a student learns in a year for math and reading tests, respectively. These results hold true when the main specification is changed, splitting the sample, collapsing the data at school level, and using other climate specifications. The paper aims to improve understanding of how to deal with the impacts of climate change on learning outcomes in developing countries. The evidence suggests that conditional cash transfer programs can mitigate the negative effects of higher temperatures on students’ learning outcomes in math and reading.
Journal
Journal Volume
Journal Issue

Related items

Showing items related by metadata.

  • Publication
    Responding to Threats of Climate Change Mega-Catastrophes
    (2009-11-01) Kousky, Carolyn; Rostapshova, Olga; Toman, Michael; Zeckhauser, Richard
    There is a low but uncertain probability that climate change could trigger "mega-catastrophes," severe and at least partly irreversible adverse effects across broad regions. This paper first discusses the state of current knowledge and the defining characteristics of potential climate change mega-catastrophes. While some of these characteristics present difficulties for using standard rational choice methods to evaluate response options, there is still a need to balance the benefits and costs of different possible responses with appropriate attention to the uncertainties. To that end, the authors present a qualitative analysis of three options for mitigating the risk of climate mega-catastrophes - drastic abatement of greenhouse gas emissions, development and implementation of geoengineering, and large-scale ex ante adaptation - against the criteria of efficacy, cost, robustness, and flexibility. They discuss the composition of a sound portfolio of initial investments in reducing the risk of climate change mega-catastrophes.
  • Publication
    Agreeing on Robust Decisions : New Processes for Decision Making under Deep Uncertainty
    (World Bank, Washington, DC, 2014-06) Kalra, Nidhi; Hallegatte, Stephane; Lempert, Robert; Brown, Casey; Fozzard, Adrian; Gill, Stuart; Shah, Ankur
    Investment 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
    Designing Climate Change Adaptation Policies : An Economic Framework
    (2011-02-01) Lecocq, Franck; Hallegatte, Stephane; de Perthuis, Christian
    Adaptation has long been neglected in the debate and policies surrounding climate change. However, increasing awareness of climate change has led many stakeholders to look for the best way to limit its consequences and has resulted in a large number of initiatives related to adaptation, particularly at the local level. This report proposes a general economic framework to help stakeholders in the public sector to develop effective adaptation strategies. To do so, it lays out the general issues involved in adaptation, including the role of uncertainty and inertia, and the need to consider structural changes in addition to marginal adjustments. Then, it identifies the reasons for legitimate public action in terms of adaptation, and four main domains of action: the production and dissemination of information on climate change and its impacts; the adaptation of standards, regulations and fiscal policies; the required changes in institutions; and direct adaptation actions of governments and local communities in terms of public infrastructure, public buildings and ecosystems. Finally, the report suggests a method to build public adaptation plans and to assess the desirability of possible policies.
  • Publication
    A Note on the Economic Cost of Climate Change and the Rationale to Limit it Below 2°C
    (World Bank, Washington, DC, 2010-01) Dumas, Patrice; 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.
  • Publication
    Adapting to Climate Change : Assessing World Bank Group Experience--Phase III of the World Bank Group and Climate Change
    (World Bank, Washington, DC, 2012) Independent Evaluation Group
    This paper constitutes the third and final volume of a series of assessments of the World Bank Group's engagement with climate change issues. The first focused on World Bank involvement in policy issues related to greenhouse gas mitigation. It was mainly concerned with the potential for energy price reform and energy efficiency policies to yield dividends in growth, fiscal savings, and climate change mitigation. The second volume examined project-level lessons related to greenhouse gas mitigation. This volume draws lessons from World Bank and International Finance Corporation (IFC) engagement in climate change adaptation. Like its predecessors, but to an even greater extent, this evaluation has a strong focus on learning, as the Bank Group explores a newly defined agenda. Climate change adaptation has only recently captured widespread policy attention. In strong contrast to climate mitigation, whose progress can be tracked along a single global metric (the atmospheric concentration of greenhouse gases), adaptation takes many forms, is intensely local, and resists easy definition and measurement. To a much greater extent even than climate change mitigation, adaptation is intertwined with development. Thus this evaluation looks not only at activities explicitly labeled 'climate adaptation' but also at a selection of those that might be expected to be adaptive, even if not so labeled.

Users also downloaded

Showing related downloaded files

  • Publication
    Guide to the Debt Management Performance Assessment Tool
    (Washington, DC, 2008-02-05) World Bank
    The purpose of this document is to provide guidance and supplemental information to assist with country assessments of debt management performance, using the Debt Management Performance Assessment (DeMPA) tool. The DeMPA is a methodology used for assessing public debt management performance through a comprehensive set of 15 performance indicators spanning the full range of government Debt Management (DeM) functions. It is based on the principles set out in the International Monetary Fund (IMF) and World Bank guidelines for public debt management, initially published in 2001 and updated in 2003. It is modeled after the Public Expenditure and Financial Accountability (PEFA) framework for performance measurement of public financial management. The DeMPA has been designed to be a user-friendly tool to undertake an assessment of the strengths and weaknesses in government DeM practices. This guide provides additional background and supporting information so that a no specialist in the area of debt management may undertake a country assessment effectively. The guide can be used by assessors in preparing for and undertaking an assessment. It is particularly useful for understanding the rationale for the inclusion of the indicators, the scoring methodology, and the list of supporting documents or evidence required, and the questions that could be asked for the assessment.
  • Publication
    Crime and Violence in Central America : A Development Challenge - Main Report
    (World Bank, 2011-01-01) World Bank
    Crime and violence are now a key development issue for Central American countries. In three nations El Salvador, Guatemala, and Honduras crime rates are among the top five in Latin America. This report argues that successful strategies require actions along multiple fronts, combining prevention and criminal justice reform, together with regional approaches in the areas of drug trafficking and firearms. It also argues that interventions should be evidence based, starting with a clear understanding of the risk factors involved and ending with a careful evaluation of how any planned action might affect future options. In addition, the design of national crime reduction plans and the establishment of national cross-sectoral crime commissions are important steps to coordinate the actions of different government branches, ease cross-sectoral collaboration and prioritize resource allocation. Of equal importance is the fact that national plans offer a vehicle for the involvement of civil society organizations, in which much of the expertise in violence prevention and rehabilitation resides. Prevention efforts need to be complemented by effective law enforcement. The required reforms are no longer primarily legislative in nature because all six countries have advanced toward more transparent adversarial criminal procedures. The second-generation reforms should instead help deliver on the promises of previous reforms by: (i) strengthening key institutions and improving the quality and timeliness of the services they provide to citizens; (ii) improving efficiency and effectiveness while respecting due process and human rights; (iii) ensuring accountability and addressing corruption; (iv) increasing inter-agency collaboration; and (v) improving access to justice, especially for poor and disenfranchised groups. Specific interventions reviewed in the report include: information systems and performance indicators as a prerequisite to improve inter-institutional coordination and information sharing mechanisms; an internal overhaul of court administration and case management to create rapid reaction, one-stop shops; the strengthening of entities that provide legal counseling to the poor and to women; and the promotion of alternative dispute-resolution mechanisms and the implementation of community policing programs.
  • Publication
    Europe and Central Asia Economic Update, Fall 2024: Better Education for Stronger Growth
    (Washington, DC: World Bank, 2024-10-17) Izvorski, Ivailo; Kasyanenko, Sergiy; Lokshin, Michael M.; Torre, Iván
    Economic growth in Europe and Central Asia (ECA) is likely to moderate from 3.5 percent in 2023 to 3.3 percent this year. This is significantly weaker than the 4.1 percent average growth in 2000-19. Growth this year is driven by expansionary fiscal policies and strong private consumption. External demand is less favorable because of weak economic expansion in major trading partners, like the European Union. Growth is likely to slow further in 2025, mostly because of the easing of expansion in the Russian Federation and Turkiye. This Europe and Central Asia Economic Update calls for a major overhaul of education systems across the region, particularly higher education, to unleash the talent needed to reinvigorate growth and boost convergence with high-income countries. Universities in the region suffer from poor management, outdated curricula, and inadequate funding and infrastructure. A mismatch between graduates' skills and the skills employers are seeking leads to wasted potential and contributes to the region's brain drain. Reversing the decline in the quality of education will require prioritizing improvements in teacher training, updated curricula, and investment in educational infrastructure. In higher education, reforms are needed to consolidate university systems, integrate them with research centers, and provide reskilling opportunities for adult workers.
  • Publication
    The Mexican Social Protection System in Health
    (World Bank, Washington DC, 2013-01) Bonilla-Chacín, M.E.; Aguilera, Nelly
    With a population of 113 million and a per-capita Gross Domestic Product, or GDP of US$10,064 (current U.S. dollars), Mexico is one of the largest and highest-income countries in Latin America and the Caribbean (LAC). The country has benefited from sustained economic growth during the last decade, which was temporarily interrupted by the financial and economic crisis. Real GDP is projected to grow 3.8 percent and 3.6 percent in 2012 and 2013, respectively (International Monetary Fund, or IMF 2012). Despite this growth, poverty in the country remains high; with half of the population living below the national poverty line. The country is also highly heterogeneous, with large socioeconomic differences across states and across urban and rural areas. In 2010, while the extreme poverty ratio in the Federal District and the states of Colima and Nuevo Leon was below 3 percent, in Chiapas, Guerrero, and Oaxaca it was 25 percent or higher. These large regional differences are also found in other indicators of well-being, such as years of schooling, housing conditions, and access to social services. This case study assesses key features and achievements of the Social Protection System in Health (Sistema de Proteccion Social en Salud) in Mexico, and particularly of its main pillar, Popular Health Insurance (Seguro Popular, PHI). It analyzes the contribution of this policy to the establishment and implementation of universal health coverage in Mexico. In 2003, with the reform of the General Health Law, the PHI was institutionalized as a subsidized health insurance scheme open to the population not covered by the social security schemes. Today, the PHI covers all of its intended affiliates, about 52 million people
  • Publication
    Classroom Assessment to Support Foundational Literacy
    (Washington, DC: World Bank, 2025-03-21) Luna-Bazaldua, Diego; Levin, Victoria; Liberman, Julia; Gala, Priyal Mukesh
    This document focuses primarily on how classroom assessment activities can measure students’ literacy skills as they progress along a learning trajectory towards reading fluently and with comprehension by the end of primary school grades. The document addresses considerations regarding the design and implementation of early grade reading classroom assessment, provides examples of assessment activities from a variety of countries and contexts, and discusses the importance of incorporating classroom assessment practices into teacher training and professional development opportunities for teachers. The structure of the document is as follows. The first section presents definitions and addresses basic questions on classroom assessment. Section 2 covers the intersection between assessment and early grade reading by discussing how learning assessment can measure early grade reading skills following the reading learning trajectory. Section 3 compares some of the most common early grade literacy assessment tools with respect to the early grade reading skills and developmental phases. Section 4 of the document addresses teacher training considerations in developing, scoring, and using early grade reading assessment. Additional issues in assessing reading skills in the classroom and using assessment results to improve teaching and learning are reviewed in section 5. Throughout the document, country cases are presented to demonstrate how assessment activities can be implemented in the classroom in different contexts.