Robert Lempert

• PhD Physics
• RAND Corporation

Media narratives employed in contemporary journalism, including data journalism, are critical in shaping public understanding of the complex systems that affect our lives. Depicting a chain of events in a “story” format, narratives are constructed with detailed, precise, and well-researched information based on character identification, human emoti...

Standardized and/or centralized proactive research governance can lessen tensions

Green Infrastructure (GI) measures are increasingly used for climate adaptation in urban areas, but it remains a challenge to evaluate their effectiveness and strategically allocate investment. Planning GI is subject to deep uncertainties and requires navigating tradeoffs between multiple objectives. Many-Objective Robust Decision Making (MORDM) ca...

Inclusive, participatory governance is a key enabler of effective responses to natural hazard risks exacerbated by climate change. This paper describes a community-level co-design process among academic, state, and federal scientists and the community of Sitka, Alaska to develop a novel landslide warning system for this small coastal town. The dece...

The Working Group II contribution to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) provides a comprehensive assessment of the scientific literature relevant to climate change impacts, adaptation and vulnerability. The report recognizes the interactions of climate, ecosystems and biodiversity, and human societie...

Nature-based solutions provide adaptation and mitigation benefits for climate change as well as contributing to other sustainable development goals (high confidence). Effective nature-based climate change mitigation stems from inclusive decision-making and adaptive management pathways that deliver climate-resilient systems serving multiple sustaina...

This report is a compendium of expert insights regarding opportunities for investing in science and technology to increase U.S. ability to engage in long-term competition in undergoverned spaces. This exploration marks an initial step toward developing a functional perspective on determining whether new approaches to strategy and engagement are war...

The coronavirus disease 2019 pandemic required significant public health interventions from local governments. Early in the pandemic, RAND researchers developed a decision support tool to provide policymakers with insight into the trade-offs they might face when choosing among nonpharmaceutical intervention levels. Using an updated version of the m...

The management of climate-related risks have become increasingly important and more frequently practised across many sectors of society. Concurrently, there has been a proliferation of guidance documents designed to help public, private, and civil society organisations conduct these activities. This study compares the UKCIP climate risk management...

The COVID-19 pandemic required significant public health interventions from local governments. Although nonpharmaceutical interventions often were implemented as decision rules, few studies evaluated the robustness of those reopening plans under a wide range of uncertainties. This paper uses the Robust Decision Making approach to stress-test 78 alt...

Climate change generates multifaceted and difficult-to-measure risks to human and natural systems. Now, research offers a composite indicator of global climate risk that may help track progress in addressing climate change.

The coronavirus disease 2019 pandemic required significant public health interventions from local governments. Early in the pandemic, RAND researchers developed a decision support tool to provide policymakers with insight into the trade-offs they might face when choosing among nonpharmaceutical intervention levels. Using an updated version of the m...

Amid global scarcity of COVID-19 vaccines and the threat of new variant strains, California and other jurisdictions face the question of when and how to implement and relax COVID-19 Nonpharmaceutical Interventions (NPIs). While policymakers have attempted to balance the health and economic impacts of the pandemic, decentralized decision-making, dee...

This paper uses the Robust Decision Making approach to stress-test California's COVID-19 reopening strategy considering a range of uncertainties. These simulations reveal the characteristics of robust, non-dominated COVID-19 exit strategies.

Real-world experience underscores the complexity of interactions among multiple drivers of climate change risk and of how multiple risks compound or cascade. However, a holistic framework for assessing such complex climate change risks has not yet been achieved. Clarity is needed regarding the interactions that generate risk, including the role of...

Connected vehicles (CV) comprise a broad class of capabilities enabled by automobiles, other vehicles, and components of the roadway system communicating with each other. A fast growing commercial market, CV has the potential for significant, but heretofore under-explored societal benefits. This study employs a scenario analysis to estimate environ...

Lustick and Tetlock (2021) present a distinctive, persuasive case for theory‐guided simulation and its use in the intelligence community (IC). The usefulness of their insight can be expanded by recognizing the relationship between the forecasting project, the decision‐aiding project, and the knowledge project. We point out further issues for consid...

Many of today's most pressing policy challenges are usefully characterized as wicked problems. With contested framings parties to a decision disagree not only on potential solutions, but on the nature of the problem they are trying to solve. The quantitative tools of risk and policy analysis, commonly designed to develop and compare choices within...

Decision makers need better insights about solutions to accelerate adaptation efforts. Defining the concept of solution space and revealing the forces and strategies that influence this space will enable decision makers to define pathways for adaptation action. .

Problem, research strategy, and findings: Prediction-based approaches, the heart of current transportation planning practice, are inadequate for informing transportation decisions in today’s rapidly changing conditions. In this study we offer an initial demonstration of how robust decision making (RDM) might enhance current long-range planning by a...

The quest for predictions—and a reliance on the analytical methods that require them—can prove counter-productive and sometimes dangerous in a fast-changing world.

Notwithstanding current heavy dependence on gas-fired electricity generation in the Eastern African Power Pool (EAPP), hydropower is expected to play an essential role in improving electricity access in the region. Expansion planning of electricity infrastructure is critical to support investment and maintaining balanced consumer electricity prices...

Participatory modeling aims to incorporate stakeholders into the process of developing models for the purpose of eliciting information, appropriately reflecting stakeholder interests and concerns, and improving stakeholder understanding, and acceptance of the analysis. Participatory modeling, using causal loop diagramming (CLD), was used to explore...

Chapter 4 "Economic Growth, Human Development, and Welfare" of the 2018 Report of the International Panel on Social Progress (IPSP). Mission of the IPSP: The International Panel on Social Progress (IPSP) will harness the competence of hundreds of experts about social issues and will deliver a report addressed to all social actors, movements, organ...

Glynn et al. (2017) note the importance of engaging stakeholders in the process of public policymaking and analysis. In particular, they highlight the central role biases, beliefs, heuristics, and values (BBVH) play in such engagement. However, the framework they propose neglects uncertainty, which significantly restricts any ability to engage effe...

Many institutions worldwide are considering how to include uncertainty about future changes in sea-levels and storm surges into their investment decisions regarding large capital infrastructures. Here we examine how to characterize deeply uncertain climate change projections to support such decisions using Robust Decision Making analysis. We addres...

Scenario techniques are a teeming field in energy and environmental research and decision making. This Thematic Issue (TI) highlights quantitative (computational) methods that improve the development and use of scenarios for dealing with the dual challenge of complexity and (deep) uncertainty. The TI gathers 13 articles that describe methodological...

Climate change challenges conservation planners in making decisions about habitat site selection and augmentation. This pilot study explores the use of Robust Decision Making (RDM), a decision analytic approach employed in water and coastal management, for conservation decision-making. It employs the RDM approach to design a theoretical decision ex...

Climate change can significantly affect water quality, in addition contributing non-stationarity and deep uncertainty that complicates water quality management. But most of the total maximum daily load (TMDL) implementation plans crafted to meet water quality standards in the USA are developed assuming stationary climate and at best a small number...

Decision support tools are known to influence and facilitate decisionmaking through the thoughtful construction of the decision environment. However, little research has empirically evaluated the effects of using scenarios and forecasts. In this research, we asked participants to recommend a fisheries management strategy that achieved multiple obje...

Individuals use values to frame their beliefs and simplify their understanding when confronted with complex and uncertain situations. The high complexity and deep uncertainty involved in climate risk management (CRM) lead to individuals' values likely being coupled to and contributing to their understanding of specific climate risk factors and mana...

When developing computational models to analyze the tradeoffs between climate risk management strategies (i.e., mitigation, adaptation, or geoengineering), scientists make explicit and implicit decisions that are influenced by their beliefs, values and preferences. Model descriptions typically include only the explicit decisions and are silent on v...

Background: Decision analysis-a systematic approach to solving complex problems-offers tools and frameworks to support decision making that are increasingly being applied to environmental challenges. Alternatives analysis is a method used in regulation and product design to identify, compare, and evaluate the safety and viability of potential subs...

Computer simulation models can generate large numbers of scenarios, far more than can be effectively utilized in most decision support applications. How can one best select a small number of scenarios to consider? One approach calls for choosing scenarios that illuminate vulnerabilities of proposed policies. Another calls for choosing scenarios tha...

Scenarios are widely used for long-term climate and energy analysis. However, in the great majority of studies with a handful of scenarios or scenario categories, both scenario developers and users capture only a subset of future uncertainties. We propose three focal points for reinvigorating the scenario technique to expand uncertainty considerati...

To successfully limit climate change, today's greenhouse gas mitigation policies should encourage reductions that will continue for decades. History suggests, however, that some policy reforms lead to societal changes that persist over the long-term while others fade without long-term effect. Current climate policy literature provides little guidan...

This book evaluates -using for the first time a single consistent methodology and the state-of-the-arte climate scenarios-, the impacts of climate change on hydro-power and irrigation expansion plans in Africa’s main rivers basins (Niger, Senegal, Volta, Congo, Nile, Zambezi, Orange); and outlines an approach to reduce climate risks through suitabl...

Policymakers know that the risks associated with climate change mean they need to cut greenhouse-gas emissions. But uncertainty surrounding the likelihood of different scenarios makes choosing specific policies difficult.

Introduction and Key Concepts This chapter addresses the foundations of decision making with respect to climate impact, adaptation, and vulnerability (CIAV). The Fourth Assessment Report (AR4) summarized methods for assessing CIAV (Carter et al., 2007), which we build on by surveying the broader literature relevant for decision making. Decision mak...

Decision support for impacts, adaptation, and vulnerability is expanding from science-driven linear methods to a wide range of methods drawing from many disciplines (robust evidence, high agreement). This chapter introduces new material from disciplines including behavioral science, ethics, and cultural and organizational theory, thus providing a b...

Benefit-cost analysis (BCA) aims to help people make better decisions. But BCA does not always serve this role as well as intended. In particular, BCA’s aim of aggregating all attributes of concern to decision makers into a single, best-estimate metric can conflict with the differing world views and values that may be an inherent characteristic of...

Decision support for impacts, adaptation, and vulnerability is expanding from science-driven linear methods to a wide range of methods drawing from many disciplines (robust evidence, high agreement). This chapter introduces new material from disciplines including behavioral science, ethics, and cultural and organizational theory, thus providing a b...

Southwestern United States paleoclimate reconstructions feature droughts that are longer and higher in magnitude than any water shortage during the twentieth century, and thus could aid water managers in planning for future severe droughts. This research used the robust decision-making (RDM) analytical framework to incorporate paleoclimate informat...

With hard-to-predict changes in future demand, climate, supply options, technological opportunities, and budgetary constraints, water agency plans should be flexible and robust, designed to meet agency goals over a wide range of plausible future conditions. But current state-of-the-art approaches to water planning make it difficult to craft flexibl...

We report results of a series of experiments on decision-making in the presence of irreducibly imprecise probabilities of negative and undesirable outcomes. Subjects faced decisions among actions where the payoffs depend on the probability of drawing balls from an urn whose composition was not fully known. Consistent with the vagueness avoidance hy...

In many decision contexts, there exists a mismatch between the types of information most useful for decision making and the information that can currently be provided by climate models. This talk will describe how using climate information with a robust decision framework can help address these challenges, using examples from flood risk and water r...

Scenario planning traditionally relies on qualitative methods to choose its scenarios. Recently, quantitative decision support tools have also begun to facilitate such choices. This study uses behavioral experiments and structured decision-maker interviews to evaluate the results of “scenario discovery,” a quantitative method that defines scenarios...

Decision support for impacts, adaptation, and vulnerability is expanding from science-driven linear methods to a wide range of methods drawing from many disciplines (robust evidence, high agreement). This chapter introduces new material from disciplines including behavioral science, ethics, and cultural and organizational theory, thus providing a b...

Scenario discovery offers a new means to characterize and communicate the information in computer simulation models under conditions of deep uncertainty. The approach first defines scenarios as the future states of world where a proposed policy fails to meet its goals and then uses statistical algorithms to find concise descriptions of such regions...

Climate information alone cannot be sufficient for anticipating and reducing climate impacts. Enhanced vulnerability science is needed, including local to global monitoring, to support effective anticipatory efforts to increase societal resilience to potentially disruptive events.

Ho Chi Minh City faces significant and growing flood risk. Recent risk reduction efforts may be insufficient as climate and socio-economic conditions diverge from projections made when those efforts were initially planned. This study demonstrates how robust decision making can help Ho Chi Minh City develop integrated flood risk management strategie...

This paper introduces many objective robust decision making (MORDM). MORDM combines concepts and methods from many objective evolutionary optimization and robust decision making (RDM), along with extensive use of interactive visual analytics, to facilitate the management of complex environmental systems. Many objective evolutionary search is used t...

In this paper, we review the need for, use of, and demands on climate modeling to support so‐called ‘robust’ decision frameworks, in the context of improving the contribution of climate information to effective decision making. Such frameworks seek to identify policy vulnerabilities under deep uncertainty about the future and propose strategies for...

Limiting the extent and effects of climate change requires the transformation of industrial, commercial, energy, and transportation systems. To achieve its goals, a near-term policy has to sustain itself for many decades. Market-based policies should prove useful in promoting such transformations. But which policies might do so most effectively? Ho...

In this paper, we review the need for, use of, and demands on climate modeling to support so-called 'robust' decision frameworks, in the context of improving the contribution of climate information to effective decision making. Such frameworks seek to identify policy vulnerabilities under deep uncertainty about the future and propose strategies for...

Socio-economic scenarios constitute an important tool for exploring the long-term consequences of anthropogenic climate change and available response options. A more consistent use of socio-economic scenarios that would allow an integrated perspective on mitigation, adaptation and residual climate impacts remains a major challenge. We assert that t...

While agreeing on the choice of an optimal investment decision is already difficult for any diverse group ofactors, priorities, and world views, the presence of deep uncertainties further challenges the decision-making framework by questioning the robustness of all purportedly optimal solutions. This paper summarizes the additional uncertainty that...

This study compares two widely used approaches for robustness analysis of decision problems: the info-gap method originally developed by Ben-Haim and the robust decision making (RDM) approach originally developed by Lempert, Popper, and Bankes. The study uses each approach to evaluate alternative paths for climate-altering greenhouse gas emissions...

Scenarios exist so that decision makers and those who provide them with information can make statements about the future that claim less confidence than do predictions, projections, and forecasts. Despite their prevalence, fundamental questions remain about how scenarios should best be developed and used. This paper proposes a particular conceptual...

The scientific community is now developing a new set of scenarios, referred to as Shared Socio-economic Pathways (SSPs) to replace the SRES scenarios. To be used to investigate adaptation and mitigation, SSPs need to be contrasted along two axes: challenges to mitigation, and challenges to adaptation. This paper proposes a methodology to develop SS...

The Metropolitan Water District of Southern California's 2010 Integrated Resource Plan Update (IRP) describes a resource investment strategy that would meet projected demand under a range of anticipated climate and demographic conditions through 2035. The IRP also identifies that alternative or additional investments may have to be considered in or...

Climate change is sure to surprise us, both in its impacts and in the technological and behavioral changes that will affect society's ability to respond (NRC 2009). Any successful response to climate change-both the challenges of limiting the magnitude of future climate change and adapting to its impacts-will clearly involve policies that evolve ov...

Advanced low-carbon energy technologies can substantially reduce the cost of stabilizing atmospheric carbon dioxide concentrations. Understanding the interactions between these technologies and their impact on the costs of stabilization can help inform energy policy decisions. Many previous studies have addressed this challenge by exploring a small...

Water managers increasingly recognize that for the purpose of evaluating future investments and operational plans it is no longer in general reasonable to assume that future climate will resemble past climate. However this "non-stationarity" of future climate presents water managers with a difficult planning challenge because the speed, characteris...

Geoengineering, the large-scale, persistent, intentional altering of the globe's climate, is increasingly mentioned as a potential response to climate change. But evaluating the risks associated with any policy toward geoengineering confronts deep uncertainties concerning not only the desirability of deploying such systems but also the consequences...

Socio-economic scenarios constitute an important tool for exploring the long-term consequences of anthropogenic climate change and available response options. They have been applied for different purposes and to a different degree in various areas of climate change analysis, typically in combination with projections of future climate change. Integr...

Climate change presents a significant planning challenge for water management agencies in the western United States. Changing precipitation and temperature patterns will disrupt their supply and extensive distribution systems over the coming decades, but the precise timing and extent of these impacts remain deeply uncertain, complicating decisions...

Scenarios provide a commonly used and intuitively appealing means to communicate and characterize uncertainty in many decision support applications, but can fall short of their potential especially when used in broad public debates among participants with diverse interests and values. This paper describes a new approach to participatory, computer-a...

How should projections of future climate change best be used to inform climate-related decisions? Providing a small number of scenarios have been one popular means to provide climate information while reflecting the uncertainty inherent in any projection of future climate. Recently there has also been increased interest in probabilistic climate for...

Based on a series of international scientific assessments, climate change has been presented to society as a major problem that needs urgently to be tackled. The science that underpins these assessments has been pre-dominantly from the realm of the natural sciences and central to this framing have been `projections' of future climate change (and it...