About

Michael Oppenheimer is the Albert G. Milbank Professor of Geosciences and International Affairs in the Princeton School of Public and International Affairs (SPIA), the Department of Geosciences, and the High Meadows Environmental Institute (HMEI) at Princeton University. He is also the Director of the Center for Policy Research on Energy and the Environment (C-PREE) and a Faculty Associate of the Program of Atmospheric and Ocean Sciences (AOS) and the Princeton Institute for International and Regional Studies (PIIRS). His research interests include the science and policy of the atmosphere, with a particular focus on climate change, the risks and impacts associated with climate change, and human responses such as adaptation. His work aims to understand the potential for dangerous outcomes of increasing greenhouse gases by exploring effects on ice sheets, sea level, coastal storm risks, and patterns of human migration. Additionally, he studies the process of scientific learning and assessments related to global change.

Research topics

• Environmental science
• Geography
• Ecology
• Biology
• Computer Security
• Natural resource economics
• Computer Science
• Geology
• Environmental resource management
• Economics
• Sociology
• Business
• Political Science
• Climatology
• Oceanography
• Fishery
• Physics
• Risk analysis (engineering)
• Meteorology

Selected publications

• Adaptation

  Climate Change · 2026-04-15

  book-chapter1st authorCorresponding

  What would it actually mean to “solve” the problem of climate change? Managing the climate isn’t a one-off achievement, Oppenheimer argues, but a challenge we’ll need to be continually wary of. Climate adaptation isn’t a single solution but an ongoing process of experimenting and improving in order to keep the risk from getting out of hand again. Some features of the policy landscape can be fixed in the short term. In the United States, for example, these include governance structures to manage adaptation, reforming insurance practices, overcoming unfairness, and the need for policymakers to engage directly with the more exposed communities. Communities vary widely; those that are more vulnerable than others will require more attention over the long term. Oppenheimer uses his experience of the record flooding caused by Hurricane Sandy a few years ago to show how New York City sought to adapt, taking steps to limit damage from future superstorms. Notwithstanding the natural disasters and crises caused by humans that marked our past, our species has been able to solve problems and put serious threats behind us. History strongly suggests we can also learn to adapt to a changed climate.

  PublisherDOI

• Observation-based probabilistic reanalysis of storm surge and sea level extremes for the United States

  Research Square · 2025-02-27 · 2 citations

  preprintOpen access
  PublisherOA PDFDOI

• US-CoastEX: Observation-based probabilistic reanalysis of storm surge and sea level extremes for the United States

  Scientific Data · 2025-08-09 · 3 citations

  articleOpen access

  Reliable estimates of storm surge and sea level extremes with proper uncertainty quantification are key for cost-effective risk/adaptation planning. However, observational estimates are often unavailable or uncertain along most coastlines owing to data scarcity. Here, we provide a fully observational-driven probabilistic dataset (US-CoastEX) of storm surge and sea level extremes for the U.S. coast (1950-2020). Non-stationary extreme storm surge distributions are generated for gauged and ungauged sites by applying Bayesian methods to the U.S. tide gauge network, complemented with additional storm data unavailable in commonly used tide gauge data. The distributions are combined with tidal peak data to estimate return periods and levels of extreme sea levels and their uncertainty. Ou results show that traditional site-by-site estimates based on existing model data, as well as regionally-aggregated analysis of standard tide gauge data, have underestimated 100-year extreme sea levels by 50% (on average) along much of the U.S. coast, especially in regions exposed to extreme storms. The data supports coastal managers to make decisions, especially in vulnerable areas where in-situ sea-level monitoring is limited.

  PublisherOA PDFDOI

• Reinforcement learning–based adaptive strategies for climate change adaptation: An application for coastal flood risk management

  Proceedings of the National Academy of Sciences · 2025-03-18 · 9 citations

  articleOpen accessSenior author

  Conventional computational models of climate adaptation frameworks inadequately consider decision-makers' capacity to learn, update, and improve decisions. Here, we investigate the potential of reinforcement learning (RL), a machine learning technique that efficaciously acquires knowledge from the environment and systematically optimizes dynamic decisions, in modeling and informing adaptive climate decision-making. We consider coastal flood risk mitigations for Manhattan, New York City, USA (NYC), illustrating the benefit of continuously incorporating observations of sea-level rise into systematic designs of adaptive strategies. We find that when designing adaptive seawalls to protect NYC, the RL-derived strategy significantly reduces the expected net cost by 6 to 36% under the moderate emissions scenario SSP2-4.5 (9 to 77% under the high emissions scenario SSP5-8.5), compared to conventional methods. When considering multiple adaptive policies, including accomodation and retreat as well as protection, the RL approach leads to a further 5% (15%) cost reduction, showing RL's flexibility in coordinatively addressing complex policy design problems. RL also outperforms conventional methods in controlling tail risk (i.e., low probability, high impact outcomes) and in avoiding losses induced by misinformation about the climate state (e.g., deep uncertainty), demonstrating the importance of systematic learning and updating in addressing extremes and uncertainties related to climate adaptation.

  PublisherOA PDFDOI

• Observations reveal changing coastal storm extremes around the United States

  Nature Climate Change · 2025-04-17 · 17 citations

  articleSenior author
  PublisherDOI

• Cost-effective ocean alkalinity enhancement confined to coastal regions.

  2025-03-25

  preprintOpen accessSenior author

  Carbon dioxide removal from the atmosphere through geoengineering technologies is inevitable to limit global warming below 2°C. Ocean alkalinity enhancement (OAE), which consists of increasing the ocean carbon sink by injecting alkaline materials into it, could potentially remove gigatons of carbon dioxide from the atmosphere every year. Limited information is, however, available on how to scale up this technology and where in the ocean it would be economically viable. In this study, we conduct a techno-economic analysis, combining biogeochemical, technical, and economic data, to identify the ocean areas where OAE is both chemically and cost-efficient. We show that net-negative emissions via OAE are only feasible and viable in coastal areas. In coastal areas, the costs and carbon emissions associated with the shipping of alkaline materials are low given the short distance to ports, minimizing the cost per ton of carbon sequestered. In contrast, in most open oceans, the long distances covered by the vessels not only increase the costs of OAE activities but also vessel carbon emissions, which can lead to net positive emissions. Implementing coastal OAE activities has policy implications as it could lead to conflicts of use with other coastal activities (conservation, fisheries, tourism, energy production), other carbon capture activities (enhance rock weathering), and international tensions in case of transboundary harm.

  PublisherDOI

• Reducing Acid Rain in Eastern North America: The Scientific Basis for an Acid Rain Control Policy

  University of Michigan Journal of Law Reform · 2025-01-01

  articleOpen access1st authorCorresponding

  This Article presents the scientific basis for an effective acid rain control policy. Part I suggests that if a choice must be made, regulation should focus primarily on sulfur dioxide emissions rather than nitrogen oxide emissions because sulfur deposition is the major cause of watershed acidification. Part II explains the need for at least a fifty percent reduction in sulfur dioxide emissions to meet a "safe" deposition level. Part III specifies the geographical allocation of sulfur emission reductions necessary to attain target deposition levels in the northeastern United States and southeastern Canada. The Article concludes by demonstrating the need for swift adoption and implementation of an effective acid deposition control strategy in light of large future risks of accumulating irreversible damage.

  PublisherOA PDFDOI

• Quantifying the economic costs of urban heat islands in the USA

  2025-05-21

  preprintOpen accessSenior author

  The combination of global warming and urban heat islands (UHI) leads to a range of socio-economic problems, including labor productivity reduction, health burdens, and increased energy demand. While heat mitigation strategies can substantially alleviate local heat stress, practical climate mitigation policies require a careful evaluation of the benefits and costs of different heat mitigation solutions. The baseline cost of UHI without intervention is of critical importance since it serves as a reference for comparing different mitigation options and informs the unquantified economic losses that cities endure due to their UHIs. Previous economic studies have focused on the economic effects of climate change and greenhouse gas mitigations, yet a quantitative assessment of this baseline cost of UHI remains lacking due to an almost universal lack of urban representation in climate datasets. This gap limits policymakers’ ability to develop economically rational action plans to reduce urban heat stress.This study aims to: (1) quantify the economic implications of UHI in the contiguous United States, and (2) perform a cost-benefit analysis of various mitigation strategies to develop cost-efficient heat mitigation portfolios. Using high-resolution climate data with urban climate representation and sectoral impact models, we have quantified the UHI-induced additional mortality rate, energy consumption, and labor loss. By incorporating monetization methods in econometric models, our preliminary assessment shows that UHI significantly amplifies the economic costs associated with regional heat stress. Our ongoing analyses aim to estimate the cost of implementing various urban adaptation strategies, including urban green, radiative cooling, and blue infrastructure, and provide a cost-benefit assessment to guide policymakers in designing effective urban climate adaptation plans.

  PublisherDOI

• Hurricane Ida’s blackout-heatwave compound risk in a changing climate

  Nature Communications · 2025-05-15 · 14 citations

  articleOpen accessSenior author

  The emerging tropical cyclone (TC)-blackout-heatwave compound risk under climate change is not well understood. In this study, we employ projections of TCs, sea level rise, and heatwaves, in conjunction with power system resilience modeling, to evaluate historical and future TC-blackout-heatwave compound risk in Louisiana, US. We find that the return period for a compound event comparable to Hurricane Ida (2021), with approximately 35 million customer hours of simultaneous power outage and heatwave exposure in Louisiana, is around 278 years in the historical climate of 1980–2005. Under the SSP5-8.5 emissions scenario, this return period is projected to decrease to 16.2 years by 2070–2100, a ~17 times reduction. Under the SSP2-4.5 scenario, it decreases to 23.1 years, representing a ~12 times reduction. Heatwave intensification is the primary driver of this increased risk, reducing the return period by approximately 5 times under SSP5-8.5 and 3 times under SSP2-4.5. Increased TC activity is the second driver, reducing the return period by 40% and 34% under the respective scenarios. These findings enhance our understanding of compound climate hazards and inform climate adaptation strategies. Employing climate projections and power system modeling, the study finds that the return period for a hurricane-blackout-heatwave compound event comparable to Hurricane Ida (2021) will decrease by ~12–17 times by the end of the century due to heatwave and hurricane intensification.

  PublisherOA PDFDOI

• Faulty science and faulty statistics can't stop sea level acceleration: An expression of concern regarding Voortman, H. G., & De Vos, R. (2025). A Global Perspective on Local Sea Level Changes. Journal of Marine Science and Engineering, 13(9), 1641.

  2025-09-12

  preprintOpen access

  Voortman & de Vos (2025) attempt to test for acceleration in relative sea-level (RSL) records from 243 tide gauges. They claim to have identified statistically significant acceleration in only 12 of the 243 gauges and conclude that “This pattern is inconsistent with sea level acceleration driven by global phenomena.” This result, which stands in contrast both to other studies conducting similar tide-gauge analyses (e.g., Wang et al., 2021, 2025) and the broader body of knowledge regarding global-mean sea level change and its drivers (e.g., Fox-Kemper et al., 2021), demands scrutiny. Yet the reviewers failed to recognize the context of this manuscript and the breadth of the existing literature, resulting in at best a superficial review. Upon close examination, we believe the paper contains fatal methodological flaws that compromise the validity of its conclusions and merit retraction.

  PublisherOA PDFDOI

Recent grants

• Collaborative Research: Assessing Assessments: A Historical and Philosophical Study of Scientific Assessments for Environmental Policy in the Late 20th Century

  NSF · $387k · 2010–2013

Frequent coauthors

• Robert E. Kopp

  Rutgers, The State University of New Jersey

  216 shared

• Scott Kulp

  Climate Central

  67 shared

• Benjamin Strauss

  Climate Central

  61 shared

• Klaus Desmet

  Southern Methodist University

  54 shared

• Esteban Rossi‐Hansberg

  University of Chicago

  54 shared

• D. J. Rasmussen

  Princeton University

  53 shared

• Dávid Krisztián Nagy

  Pompeu Fabra University

  52 shared

• Maya K. Buchanan

  Johns Hopkins University

  47 shared

Education

• Ph.D., Chemical Physics

  University of Chicago

  1970

• S.B. , Chemistry

  M.I.T.

  1966