Jonathan Magnolia Gilligan

Research Interests

Thu, 15 Jun 2017 00:00:00 +0000

Overview

I work primarily at the intersection of natural science, social science, and public policy with a focus on coupled human-natural systems and on the ways in which scientific knowledge and uncertainty affect policy decisions about the environment.

My current work makes extensive use of agent-based models to simulate the ways that small changes in behavior at the individual level can add up to large-scale shifts at the level of the whole population, giving what is often referred to as “emergent phenomena.” These models have the potential to help us identify vulnerabilities to environmental stress and opportunities to promote sustainable adaptations.

Current Research Projects

Tue, 10 Sep 2019 00:00:00 +0000

I am currently pursuing research in three areas:

New directions in US climate policy: Integrating insights from social and behavioral science, engineering, and legal scholarship to develop pragmatic approaches that could quickly reduce greenhouse gas emissions in the US during a time when major federal regulations seem unlikely.
- An active subset of this research focuses on the energy needs and associated greenhouse gas emissions from large data centers, and the challenges and opportunities for private-sector actions to address these as generative artificial intelligence is growing rapidly.
Application of machine learning methods to understanding the risks of “forever chemicals” (PFAS, or per- and poly-fluoroalkyl substances) contamination in surface and groundwater across Tennessee, and the implications for public health and burdens on community water systems.

Previous Research Projects

Thu, 15 Jun 2017 00:00:00 +0000

Here are some projects I worked on previously:

Environmental stress and human migration in southwestern Bangladesh: A comparison of co-evolving natural and human landscapes in a physically and culturally diverse context.
Data-driven approaches to understanding the impacts of gentrification on vulnerable populations, with a focus on air quality and access to mobility and public transit.
Opportunities and challenges for implementing sustainable and resilient energy, transportation, and telecommunications infrastructure across the Southeastern United States, with an emphasis on the potential for this infrastructure to address growing disparities between urban and rural communities.

What Students Do

Thu, 15 Jun 2017 00:00:00 +0000

Students working with me are engaged in a variety of projects to combine knowledge about the physical environment and social, political, and economic conditions. This can include analysis of remote-sensing imagery from satellites, working with GIS databases, developing agent-based models, and conducting spatiotemporal statistical analysis.

Students write and publish papers, often as first-author, in scientific journals and present research results at national and international conferences.

Current Students

Fernanda (Ferna) Alvarez-Carrascal is applying advanced Bayesian statistical methods to understanding the geographical distribution of drinking-water contamination across the United States and the implications for environmental justice: which communities and demographic groups are most vulnerable to exposure to contaminated drinking water? She also studies the adoption of home solar energy and household energy-efficiency improvements among Latino/a households in urban and rural areas in Tennessee and Washington.

Bayesian Statistical Methods

Sat, 10 Dec 2022 00:00:00 +0000

This course, for graduate students, provides an introduction to Bayesian statistics, with a focus on both practical application of Bayesian regression methods to data as well as philosophical background on statistical inference and interpretation of statistical analyses. Topics include Bayes’s theorem and tools for applying it, including quadratic approximations, and Hamiltonian Monte Carlo sampling. Advanced methods include mixture models, multilevel regression methods, models incorporating ordinary differential equations, and critical evaluation of statistical models and modeling analyses.

Adaptation as mitigation

Wed, 26 Nov 2025 00:00:00 +0000

The damage from wildfires and hurricanes in recent years has resulted in extensive emergency and longer-term responses. This Article identifies an overlooked and inconvenient truth about these types of disasters: many climate adaptation efforts should also achieve climate mitigation. This is not a popular conclusion. Scientists have recognized the importance of the adaptationmitigation nexus for over a decade, but the climate change legal literature typically treats adaptation (adjusting to or reducing the harm of climate change) and mitigation (reducing the causes of anthropogenic climate change) as discrete alternatives. Adaptation will often occur in the midst of short-term emergency responses in which achieving mitigation is far from the minds of policymakers, and including mitigation in long-term adaptation planning could create bureaucratic obstacles that bog down decision-making. Yet future generations will ask whether we accounted for their well-being as we responded to protect the well-being of the current generation or whether we dismissed these concerns and made future disasters worse. The Article argues that adaptation scholarship and policies should reflect the fact that reducing climate risks will often be far more difficult and expensive if mitigation opportunities are missed. As a first step, the Article offers two principles to guide research and policymaking on this topic: mitigate-while-adapting and adapt-to-mitigate. The Article explores the basis for these principles and their implications for public and private governance.

Unplugging the artificial intelligence energy emergency

Wed, 26 Nov 2025 00:00:00 +0000

This Article explores the assumptions that underly projections of extraordinary growth in artificial intelligence (AI)-driven data center energy demand, and it identifies the potential for reducing consumer and corporate energy costs and demand through energy and environmental disclosures. The Article explores AI-driven electricity demand assumptions by examining the history of electricity demand over-predictions and by proposing research to address the over-prediction bias. It then identifies viable initiatives that may be able to shift the timing or amount of demand, and it eschews the tendency to propose government legislative or regulatory interventions on AI use or emissions that are infeasible for the foreseeable future. Focusing on household behavior, it identifies examples of successful disclosure programs and presents exploratory new empirical data to explain how electricity use and environmental disclosures have the potential to shift consumer behavior. Turning to corporate behavior, it then explore corporate environmental commitments and discusses ways to enhance the gap-filling role of these commitments. The Article concludes by identifying additional research initiatives to better understand and address the role of information in addressing the energy and environmental challenges arising from AI-driven electricity demand.

Future-making beyond (im)mobility through tethered resilience

Tue, 25 Nov 2025 00:00:00 +0000

Adaptation to climate change goes beyond the migration-non-migration divide. Families and communities combine mobility with rootedness, drawing on cultural ties, intergenerational learning, and lived knowledge to navigate risks and shape long-term futures.

Tethered resilience: A new concept for understanding climate change, migration, and adaptation

Tue, 25 Nov 2025 00:00:00 +0000

I have a new paper Nature Climate Change, “Future-making beyond (Im)mobility through tethered reilience,” led by Bishawjit Mallick, that introduces a concept of tethered resilience, related to people’s attachment to their native communities and place, and argues that this concept provides new and useful ways to think about connections among climate change, migration, and adaptation.

Vanderbilt Faculty and Students Oppose Trump Compact on Higher Education

Sat, 11 Oct 2025 00:00:00 +0000

At the Vanderbilt Hustler, Jacob Stoebner reports on the Vanderbilt faculty senate and student government strongly oppossing President Trump’s proposed “Compact for Academic Excellence in Higher Educaation”

Vanderbilt Faculty Senate Opposes White House Compact

Fri, 10 Oct 2025 00:00:00 +0000

At the Nashville Scene, Julianne Akers reports on the Vanderbilt faculty senate passing a resolution opposing Trump’s so-called “Compact for Academic Excellence in Higher Education”.

The energy and environmental footprint of AI

Sat, 23 Aug 2025 00:00:00 +0000

Artificial intelligence (AI) has the potential to create major economic and social benefits but also to rapidly escalate electricity demand and its associated environmental impacts. Information has been a cornerstone of environmental law for half a century, and this Article argues that providing information to individual, corporate, and other users about the electricity demand and environmental impacts of AI can reduce those impacts without delaying development of the technology. Little is known about how AI large language models (LLMs) compare on these issues, though, and to address this shortcoming the Article provides the first comparison of the outputs of four AI environmental footprint calculators. The Article finds that running the same AI query through all four calculators produces substantial differences in outputs, with one calculator producing an estimate more than 50 times higher than another for the same type of query. These differences suggest that substantial improvements are needed in the disclosure of information, whether through international, national, state, or private standards, to provide reliable estimates of energy use and environmental impacts to users. In turn, more accurate, easily available information can create incentives for reducing the costs, energy demand, and environmental impacts of AI even in a deregulatory era.

Agent- and Individual-Based Computational Modeling

Mon, 12 Jun 2017 00:00:00 +0000

This course (for undergraduate and graduate students) introduces agent-based and individual-based computational modeling with applications to ecological, social, and behavioral sciences and engineering. It covers designing and programming models and using the models to conduct experiments.

The moral boundary of the firm

Tue, 01 Jul 2025 00:00:00 +0000

Scholars have wrestled with the legal boundary of the firm for generations. The legal boundary limits the extent to which a firm can be held liable for the torts, contractual, and regulatory obligations of other corporations. The existence of a legal boundary suggests that the law limits incentives for firms to control the climate and other environmental harms caused by their corporate suppliers. Yet recent research demonstrates that many of the largest corporations impose environmental requirements on their suppliers that exceed the legal requirements imposed on these suppliers. This suggests that some factors other than the threat of liability may be encouraging corporations to try to reduce the environmental harm caused by their suppliers. In this paper, we refer to the attributions of responsibility to firms by customers, employees, and other stakeholders as imposing a "moral boundary" on corporate action that may be more constraining than the legal boundary. Drawing on three surveys with 2,400 respondents, this Article evaluates the extent to which the public may influence this moral boundary of the firm-whether potential employees, retail customers, community members, and other stakeholders hold firms morally accountable for the environmental harms of their suppliers even if they are not legally accountable. The survey results suggest that they do: these stakeholders assign moral blame to corporate buyers for the emissions of their first-and second-tier suppliers, although the moral boundary is nuanced: the assignment of blame has limited effects on consumer behavioral intentions, increases with the control the buyer exercises over the supplier, and decreases from tier one to tier two suppliers. The Article concludes that corporate managers may be protecting the reputation-driven economic interests of their firms when they adopt environmental supply chain requirements, and it suggests the need for research on whether the moral boundary interacts with the legal boundary in ways that lead to an efficient balance between the legal boundary's incentives to take financial risks, externalize harms, and exercise limited control over third parties, and the moral boundary's incentives to be cautious about financial risks, internalize harms, and exercise a greater degree of control over third parties.

Protect transgender scientists

Thu, 19 Jun 2025 00:00:00 +0000

Transgender and gender nonconforming (TGnC) people are a primary target of the Trump administration. Multiple executive orders seek to erase TGnC protections; mandate denial of gender identity; and ban diversity, equity, and inclusion (DEI). Changes to federal funding policies related to TGnC individuals and DEI threaten to curtail academic diversity and freedom. Institutions have been hesitant to resist, but for many TGnC scientists—especially TGnC individuals of color, immigrants, and those with disabilities—invisibility is not an option. Anticipatory obedience, and even passive allyship, is insufficient; institutions must abandon neutrality and defend targeted communities to minimize further harm. As queer and TGnC scientists, we call on researchers at all levels—from undergraduates to university presidents—to take direct, consistent, and rapid action.

Protect Transgender Scientists

Thu, 19 Jun 2025 00:00:00 +0000

I am co-author on a letter to Science discussing the need to protect transgender and gender-nonconforming (GnC) scientists in the face of politicized attacks by the Trump administration.

Keynote talk at Planet Texas 2050 Symposium

Sun, 30 Mar 2025 00:00:00 +0000

In February, I gave the opening keynote talk at the Planet Texas 2050 symposium at the University of Texas Austin. UT has uploaded a video of my talk, “Sustainability across the University: Expanding the Disciplinary Range of Teaching, Scholarship, and Artistic Expression Responding to Environmental Change”, to YouTube.

Economic inequality plays an important role in environmental migration

Thu, 27 Mar 2025 00:00:00 +0000

I have a new paper, with Kelsea Best and Bishawjit Mallick, in which we used pattern-oriented agent-based modeling to study environmentally-driven migration in rural Bangladesh and found that economic inequality in rural villages plays a crucial role.

Economic inequality is a crucial determinant of observed patterns of environmental migration

Wed, 12 Mar 2025 00:00:00 +0000

Environmental migration occurs across spatial and temporal scales and is influenced by the dynamics of individual and collective human behavior, as well as environmental stresses. Agent-based modeling (ABM) has demonstrated potential for studying such complex processes, especially where individual decision-making is important. We developed an ABM to simulate environmental shocks, labor markets, and household livelihoods and used it to study environmental migration in rural Bangladesh. Using a pattern-oriented modeling approach, we found that an economic model of migration decisions can robustly reproduce observed patterns so long as economic inequality is properly represented. The results were sensitive to both the functional form and the parameters characterizing the distribution of land-ownership within a community. We conclude that community-level inequality has significant implications for environmental migration dynamics and should be considered in future policy interventions and research efforts.

Probability & Statistics for Geosciences

Wed, 01 Jan 2025 00:00:00 +0000

This mezzanine course, for graduate students and upper-level undergraduates , provides an introduction to probability and statistics with a focus on applied data analysis for Earth & Environmental Sciences. Topics include probability distributions, descriptive statistics, parameter estimation, hypothesis testing, linear regression, time series analysis, and multivariable statistics.

Incorporating spatial autocorrelation in dasymetric mapping: A hierarchical poisson spatial disaggregation regression model

Mon, 26 Aug 2024 00:00:00 +0000

The growing demand for spatially detailed population products in various fields continues to rise, as users shift their focus from aggregated areal totals to high-resolution grid estimates. Aggregating demographic data to areas, such as census tracts or block groups, can mask localized heterogeneities within those areas. This paper presents a new pycnophylactic (density-preserving) geospatial model for disaggregating population to high-resolution grids. We describe a Bayesian Hierarchical Poisson Spatial Disaggregation Regression Model (HPSDRM), which incorporates land cover covariates and two levels of spatial autocorrelation. We evaluated the model's predictive ability first with simulation studies, and then by disaggregating census population data for Davidson County, TN, from the census tract-level to a fine grid and comparing predicted to actual block-level population counts. The interpolated population map successfully identified spatial heterogeneities, such as hot- and cold-spots within census tracts. The HPDSRM model out-performed three other types of disaggregation modeling, which suggests the value of incorporating spatial autocorrelation. Based upon this study, HPSDRM has potential for disaggregating other demographic data, such as socioeconomic indicators.

Actions by Households Play a Surprisingly Large and Cost-Effective Role in IRA/IIJA Emissions Reductions

Thu, 01 Feb 2024 00:00:00 +0000

Mariah Caballero, Mike Vandenbergh, Elodie Currier, and I have a paper analyzing the 2021 Infrastructure Investment and Jobs Act (IIJA) and the 2022 Inflation Reduction Act (IRA). These laws include incentives for households to take voluntary actions to reduce greenhouse gas emissions, such as buying electric cars and performing energy-efficiency home renovations. We found that these incentives account for only around 11% of spending, but the household actions they stimulate are expected to produce around 40% of total emissions reductions.

These results confirm previous studies which found that incentives for individuals and households to voluntarily adopt energy efficiency actions can make powerful contributions to climate and energy policy, and should be emphasized in future policy proposals.

Incentivizing household action: Exploring the behavioral wedge in the 2021 Infrastructure Investment and Jobs Act and the 2022 Inflation Reduction Act

Fri, 26 Jan 2024 00:00:00 +0000

In the 2021 Infrastructure Investment and Jobs Act (IIJA) and the 2022 Inflation Reduction Act (IRA), the United States (U.S.) Congress placed a major bet on the importance of household actions, and the incentives for these actions may yield disproportionately large emissions reductions. Modeling estimates from Rapid Energy Policy Evaluation and Analysis Toolkit (REPEAT) suggest that the IRA's $331 billion investment can reduce carbon emissions by as much as 4% below a 2005 baseline by 2030, assuming a low-friction economic environment. To evaluate the role of household actions, we use a two-part method: 1) Policy analyses of the IRA and IIJA to identify household incentives; 2) Secondary data analysis of REPEAT's policy models to identify the potential for emissions reductions associated with household action. We find that $39 billion, or 12% of climate and energy funds in the IRA and $4.3 billion or 5.7% of clean energy and power funds in the IIJA, target voluntary household actions, and that these actions contribute 40% of the cumulative emissions reductions under the IRA and IIJA, assuming a mid-range scenario for uptake. The importance of household actions to achieving IRA and IIJA's emissions reduction goals suggests that actual impacts will likely vary by behavioral plasticity, and that program design should reflect social and behavioral science insights.

Supply, demand, and polarization challenges facing U.S. climate policies

Tue, 16 Jan 2024 00:00:00 +0000

The U.S. recently passed major federal laws supporting the energy transition, and analyses suggest that their successful implementation could reduce U.S. emissions more than 40% below 2005 levels by 2030. However, achieving maximal emissions reductions would require frictionless supply and demand responses to the laws' incentives, and implementation that avoids polarization and efforts to repeal or undercut them. In this Perspective we discuss some of these supply, demand, and polarization challenges. We highlight insights from social science research, and identify open questions needing answers, regarding how to address these challenges. The stakes are high: these new laws' successes could catalyze virtuous cycles in the energy transition, or their failures could breed cynicism about major government spending on climate change.

Modeling the dynamics of sediment transport, tides, and sea-level rise: Implications for the resilience of coastal Bengal

Tue, 12 Dec 2023 00:00:00 +0000

The coastal zone of the Ganges-Brahmaputra-Meghna (GBM) Delta is widely recognized as one of the most vulnerable places to sea-level rise (SLR), with around 57 million people living within 5 m of sea level. Sediment transported by the Ganges, Brahmaputra, and Meghna rivers has the potential to raise the land and offset SLR. There is significant uncertainty in future sediment supply and SLR, which raises questions about the sustainability of the delta. We present a simple model, driven by basic physics, to estimate the evolution of the landscape under different conditions at low computational cost. Using a single tuning parameter, the model can match observed rates of land aggradation. We find a strong negative feedback, which robustly brings land elevation into equilibrium with changing sea level. We discuss how this model can be used to investigate the dynamics of sediment transport and the sustainability of the GBM Delta.

An index of social fabric for assessing community vulnerability to natural hazards: Model development and analysis of uncertainty and sensitivity

Tue, 08 Aug 2023 00:00:00 +0000

Indices of socio-environmental vulnerability, resilience, and sustainability are well-established in assessing, mitigating, and planning for natural hazards in mitigation. Although there are many such indices, we still lack an index to measure connections and cohesion within a community—the social fabric (as we refer to it) that connects its members with each other and with the place. We propose an indicator-based index social fabric index (SoFI) to both measure and map the spatial dimension of the social fabric within and across communities. We investigate approaches to constructing social fabric indices and conduct uncertainty and sensitivity analyses for each stage of constructing the underlying model of the social fabric, which includes indicator transformation, normalization, principal component selection and rotation, and weighting. From this effort, we find that the precision of the index increases with social fabric levels, corresponding to lower social vulnerability. Global sensitivity analysis shows that the coordinate transformation and PCA selection play especially important roles in determining total uncertainty. Furthermore, the preceding step tends to absorb the uncertainty contributions of the following steps through construction interactions. Finally, we consider the importance of the emotional and psychological effects of the social fabric concept and provide suggestions for future work so that we will be able to develop a more transparent, comprehensive, and robust social fabric index model.

New paper on the sustianability of the Bengal delta

Thu, 27 Apr 2023 00:00:00 +0000

I have a new paper, led by Jess Raff, that analyzes sediment transport and sediment budgets in the Ganges-Brahmaputra-Meghna delta, and assesses the implications of sediment flow for sustainability in the face of sea-level rise and the diversion and damming of major rivers.

Sediment delivery to sustain the Ganges-Brahmaputra delta under climate change and anthropogenic impacts

Thu, 27 Apr 2023 00:00:00 +0000

The principal nature-based solution for offsetting relative sea-level rise in the Ganges- Brahmaputra delta is the unabated delivery, dispersal, and deposition of the rivers' $\sim$1 billion tonne annual sediment load. Recent hydrological transport modeling suggests that strengthening monsoon precipitation in the 21st century could increase this sediment delivery 34–60%; yet other studies demonstrate that sediment could decline 15–80% if planned dams and river diversions are fully implemented. We validate these modeled ranges by developing a comprehensive field-based sediment budget that quantifies the supply of Ganges-Brahmaputra river sediment under varying Holocene climate conditions. Our data reveal natural responses in sediment supply comparable to previously modeled results and suggest that increased sediment delivery may be capable of offsetting accelerated sea-level rise. This prospect for a naturally sustained Ganges-Brahmaputra delta presents possibilities beyond the dystopian future often posed for this system, but the implementation of currently proposed dams and diversions would preclude such opportunities.

Fulbright Scholar Award

Mon, 17 Apr 2023 00:00:00 +0000

I am very excited to announce that I have been selected for a Fulbright Scholar Award, which will allow me to spend a large part of the next academic year at the University of Calgary’s Werklund School of Education as the Fulbright Canada Research Chair in Digital Technologies and Sustainability.

Mentoring Award

Mon, 17 Apr 2023 00:00:00 +0000

I am thrilled and proud to receive a mentoring award from the Margaret Cuninggim Women’s Center at Vanderbilt, recognizing my mentorship, support, and advocacy for women at Vanderbilt, especially in STEM.

Water narratives in local newspapers within the United States

Fri, 03 Mar 2023 00:00:00 +0000

Sustainable use of water resources continues to be a challenge across the globe. This is in part due to the complex set of physical and social behaviors that interact to influence water management from local to global scales. Analyses of water resources have been conducted using a variety of techniques, including qualitative evaluations of media narratives. This study aims to augment these methods by leveraging computational and quantitative techniques from the social sciences focused on text analyses. Specifically, we use natural language processing methods to investigate a large corpus (approx. 1.8M) of newspaper articles spanning approximately 35 years (1982–2017) for insights into human-nature interactions with water. Focusing on local and regional United States publications, our analysis demonstrates important dynamics in water-related dialogue about drinking water and pollution to other critical infrastructures, such as energy, across different parts of the country. Our assessment, which looks at water as a system, also highlights key actors and sentiments surrounding water. Extending these analytical methods could help us further improve our understanding of the complex roles of water in current society that should be considered in emerging activities to mitigate and respond to resource conflicts and climate change.

Introduction to Climate Change

Mon, 12 Jun 2017 00:00:00 +0000

This course, for undergraduate students, has two major parts:

The basic scientific principles of the earth’s climate.
Human dimensions of climate change.

Webinar on Incorporating Behavior Change into Socio-Environmental Systems Models

Fri, 15 Jul 2022 00:00:00 +0000

In June, I gave the keynote talk for a webinar and panel discussion at the National Socioenvironmental Synthesis Center (SESYNC) about incorporating behavior change into socio-environmental systems models. The video of the event has now been posted to SESYNC’s YouTube channel

Applying machine learning to social datasets: A study of migration in southwestern Bangladesh using random forests

Fri, 25 Mar 2022 00:00:00 +0000

As researchers collect large amounts of data in the social sciences through household surveys, challenges may arise in how best to analyze such datasets, especially where motivating theories are unclear or conflicting. New analytical methods may be necessary to extract information from these datasets. Machine learning techniques are promising methods for identifying patterns in large datasets, but have not yet been widely used to identify important variables in social surveys with many questions. To demonstrate the potential of machine learning to analyze large social datasets, we apply machine learning techniques to the study of migration in Bangladesh. The complexity of migration decisions makes them suitable for analysis with machine learning techniques, which enable pattern identification in large datasets with many covariates. In this paper, we apply random forest methods to analyzing a large survey which captures approximately 2000 variables from approximately 1700 households in southwestern Bangladesh. Our analysis ranked the covariates in the dataset in terms of their predictive power for migration decisions. The results identified the most important covariates, but there exists a tradeoff between predictive ability and interpretability. To address this tradeoff, random forests and other machine learning algorithms may be especially useful in combination with more traditional regression methods. To develop insights into how the important variables identified by the random forest algorithm impact migration, we performed a survival analysis of household time to first migration. With this combined analysis, we found that variables related to wealth and household composition are important predictors of migration. Such multi-methods approaches may help to shed light on factors contributing to migration and non-migration.

Global Climate Change

Mon, 12 Jun 2017 00:00:00 +0000

This course, for undergraduate and graduate students, has three major parts:

The basic scientific principles of the earth’s climate.
Impacts and possible responses to climate change.
The politics of climate change.

A laboratory section gives students a chance to analyze climate data and work with interactive computer models of the climate system.

Modeling multi-level patterns of environmental migration in Bangladesh: An agent-based approach

Fri, 31 Dec 2021 00:00:00 +0000

Environmental change interacts with population migration in complex ways that depend on interactions between impacts on individual households and on communities. These coupled individual-collective dynamics make agent-based simulations useful for studying environmental migration. We present an original agent-based model that simulates environment-migration dynamics in terms of the impacts of natural hazards on labor markets in rural communities, with households deciding whether to migrate based on maximizing their expected income. We use a pattern-oriented approach that seeks to reproduce observed patterns of environmentally-driven migration in Bangladesh. The model is parameterized with empirical data and unknown parameters are calibrated to reproduce the observed patterns. This model can reproduce these patterns, but only for a narrow range of parameters. Future work will compare income-maximizing decisions to psychologically complex decision heuristics that include non-economic considerations.

A scenario of solar geoengineering governance: Vulnerable states demand, and act

Wed, 04 Aug 2021 00:00:00 +0000

The paper examines a scenario exercise concerning deployment of solar geoengineering by a small group of states that are particularly vulnerable to climate change. Two groups of participants were each asked to provide expert decision-making advice to an alliance comprising great powers, and to propose a political response to the deployment initiative. This paper discusses the initial governance proposals and examines differences and exchanges between the groups throughout the exercise. The two groups delivered distinct governance proposals. The differences, which were driven largely by divergent worldviews and assumptions about the geopolitical context, provide insights into the complexities of responses to the "free-driver" of solar geoengineering deployment, internal functioning and cohesion of coalitions, and interactions among multiple responses to climate change.

Expertise across disciplines: Establishing common ground in interdisciplinary disaster research teams

Wed, 28 Jul 2021 00:00:00 +0000

Hazards and disasters arise from interactions between environmental and social processes so interdisciplinary research is crucial to understanding and effectively managing them. Despite support and encouragement from funding agencies, universities, and journals and growing interest from researchers, interdisciplinary disaster research teams face significant obstacles, such as the difficulty of establishing effective communication and understanding across disciplines. Better understanding of interdisciplinary teamwork can also have important practical benefits for operational disaster planning and response.Social studies of science distinguishes different kinds of expertise and different modes of communication. Understanding these differences can help interdisciplinary research teams communicate more clearly and work together more effectively. The primary role of a researcher is in contributory expertise (the ability to make original contributions to a discipline); but interactional expertise in other disciplines (the ability to understand their literature and communicate with their practitioners) can play an important role in interdisciplinary collaborations. Developing interactional expertise requires considerable time and effort, which can be challenging for a busy researcher, and also requires a foundation of trust and communication among team members. Three distinct aspects of communication play important roles in effective interdisciplinary communication: dialects, metaphors, and articulation.There are different ways to develop interactional expertise and effective communication, so researchers can pursue approaches that suit their circumstances. It will be important for future research on interdisciplinary disaster research to identify best practices for building trust, facilitating communication, and developing interactional expertise.

Assessing food-energy-water resources management strategies at city scale: An agent-based modeling approach for Cape Town, South Africa

Thu, 01 Jul 2021 00:00:00 +0000

The impact of human activities and climate change occurs across a range of spatial and temporal scales, and the city or regional scale is critical for managing food-energy-water (FEW) resources. We develop a coupled human-natural system model for Cape Town, South Africa, which consists of an agent-based model and a regional hydrologic model, to study the FEW nexus connecting the agricultural, urban, and hydroelectric generation sectors. We use the model to compare three policies—a simple adaptive approach, adaptation with free water to indigent households, and water supply augmentation—and assess their ability to provide reliable FEW services to the different stakeholders under four different climate scenarios, representing moderate to severe amounts of warming. Our results indicate that Cape Town is likely to face increasing water stress as temperatures rise, and that adaptation strategies could effectively mitigate the effects of water limitations and avoid severe failures in providing FEW services across sectors. One way to manage demand for FEW services is by adjusting water price tariffs, but high prices create inequality in access to water for households with different incomes. Our analysis suggests that the water supply system in Cape Town may already be at, if not over, its sustainable capacity within the FEW nexus. Our model serves as a test-bed for assessing policies to manage stresses on water resources for the benefit of stakeholders across FEW sectors. This model can be adapted to cities and regions around the globe.

Predicting public transportation load to estimate the probability of social distancing violations

Mon, 08 Feb 2021 00:00:00 +0000

Public transit agencies struggle to maintain transit accessibility with reduced resources, unreliable ridership data, reduced vehicle capacities due to social distancing, and reduced services due to driver unavailability. In collaboration with transit agencies from two large metropolitan areas in the USA, we are designing novel approaches for addressing the afore-mentioned challenges by collecting accurate real-time ridership data, providing guidance to commuters, and performing operational optimization for public transit. We estimate rider-ship data using historical automated passenger counting data, conditional on a set of relevant determinants. Accurate ridership forecasting is essential to optimize the public transit schedule, which is necessary to improve current fixed lines with on-demand transit. Also, passenger crowding has been a problem for public transportation since it deteriorates passengers' wellbeing and satisfaction. During the COVID-19 pandemic, passenger crowding has gained importance since it represents a risk for social distancing violations. Therefore, we are creating optimization models to ensure that social distancing norms can be adequately followed while ensuring that the total demand for transit is met. We will then use accurate forecasts for operational optimization that includes (a) proactive fixed-line schedule optimization based on predicted demand, (b) dispatch of on-demand micro-transit, prioritizing at-risk populations, and (c) allocation of vehicles to transit and cargo trips, considering exigent vehicle maintenance requirements (i.e., disinfection). Finally, this paper presents some initial results from our project regarding the estimation of ridership in public transit.

Random forest analysis of two household surveys can identify important predictors of migration in Bangladesh

Fri, 01 Jan 2021 00:00:00 +0000

The decision to migrate is complex and is often influenced by a combination of economic, social, political, and environmental pressures. Household survey instruments can capture detailed information about migration histories and their contexts, but it can be challenging to identify important predictors from large numbers of covariates with standard statistical methods, such as regression analyses. Machine learning techniques are well suited to pattern identification and can identify important covariates from large datasets. We report on the application of machine learning approaches to two large surveys collected from a total of more than 2800 households in southwestern Bangladesh. We applied random forest classification and regression models to identify significant covariates with the greatest predictive power for household migration decisions. The results show that random forest models are able to identify nuances in predictors of different types of migration and migration in different communities. Random forests also outperform logistic regression and support vector machines in predicting migration in all cases analyzed. Therefore, random forest models and other machine learning methods can be useful for improving the predictive accuracy of migration models and identifying patterns in complex social datasets. Future work should continue to explore the potential of machine learning techniques applied to questions of environmental migration.

Climate law and policy: Forks in the road

Thu, 31 Dec 2020 00:00:00 +0000

This Essay provides a simple heuristic to enable public and private policymakers to focus on the most important climate mitigation options. Policymakers face a blizzard of information, advocacy, and policy options, and it is easy to lose sight of the forest for the trees. Many options are attractive on the surface but will not meaningfully address the problem or are unlikely to be adopted in the foreseeable future. If policymakers make the right decision when confronting three essential choices or forks in the road, though, the result will be 60% to 70% reductions in greenhouse gas emissions, an amount that will keep widely-adopted climate mitigation goals in reach. The three options are decarbonization of the electrical grid, electrification of the motor vehicle fleet, and electrification of buildings. International, national, and subnational officials, philanthropists, corporate executives, advocacy group leaders, and households have the ability to prioritize these three options in their regulatory, purchasing, and other actions. If they make the right choice on these three options, many other mistakes can be made without jeopardizing the chance to achieve widely-adopted emissions targets. If they make the wrong choice, few combinations of other viable options can achieve the needed reductions. In the face of a growing consensus that major, prompt emissions reductions are required, the forks in the road approach can provide policymakers with the mental framework necessary to make smart decisions and ignore the noise surrounding climate law and policy

Beyond wickedness: Managing complex systems and climate change

Tue, 22 Dec 2020 00:00:00 +0000

This Article examines the argument that climate change is a "super wicked" problem. It concludes that the wicked problem concept is best viewed as a rhetorical device that served a valuable function in arguing against technocratic hubris in the early 1970s but is unhelpful and possibly counterproductive as a tool for modern climate policy analysis. Richard Lazarus improved on this analysis by emphasizing the urgency of a climate response in his characterization of the climate problem as "super wicked." We suggest another approach based on Charles Lindblom's "science of muddling through." The muddling through approach supports the rhetorical points for which the original wicked problem concept was introduced and provides greater practical guidance for developing new laws and policies to address climate change and other complex and messy environmental problems.

Extreme weather and marriage among girls and women in Bangladesh

Tue, 29 Sep 2020 00:00:00 +0000

Climate change interacts with social, economic, and political forces in ways that can shape demographic behavior. Yet, the link between environmental stress and marriage has received limited attention. Using survey data from 615 Bangladeshi households, we examine the relationship between extreme weather in the form of heat waves and dry spells, and the risk of marriage over the period from 1989 to 2013. We find that girls and women are at an increased risk of marrying in the year of or following heat waves. The link is strongest for women aged 18 to 23, and weakest for those 11 to 14. We also explore the hypothesis that extreme weather leads families to accept less desirable marriage proposals for daughters. We find that those who wed during periods of extreme heat married into poorer households and to husbands with less education. Similarly, those who married during abnormally dry periods married men man with less education and who were more supportive of intimate partner violence. Together these results suggest that, when Bangladeshi families face environmental shocks, they cope by hastening the marriage of daughters or accepting less desirable marriage proposals. Such practices are likely to have long-term impacts on the health and well-being of women and children, and underscore the unique vulnerabilities faced by women as climate change intensifies.

Improving Climate Change Mitigation Analysis

Fri, 18 Sep 2020 00:00:00 +0000

A major new paper in the journal One Earth from a collaboration between U.S. and European authors on the importance of incorporating behavioral, cultural, social, and political considerations into integrated assessment models of greenhouse gas emissions pathways, especially in the context of the IPCC process.

Abstract:

Limiting global warming to 2°C or less compared with pre-industrial temperatures will require unprecedented rates of decarbonization globally. The scale and scope of transformational change required across sectors and actors in society raises critical questions of feasibility. Much of the literature on mitigation pathways addresses technological and economic aspects of feasibility, but overlooks the behavioral, cultural, and social factors that affect theoretical and practical mitigation pathways. We present a tripartite framework that “unpacks”" the concept of mitigation pathways by distinguishing three factors that together determine actual mitigation: technical potential, initiative feasibility, and behavioral plasticity. The framework aims to integrate and streamline heterogeneous disciplinary research traditions toward a more comprehensive and transparent approach that will facilitate learning across disciplines and enable mitigation pathways to more fully reflect available knowledge. We offer three suggestions for integrating the tripartite framework into current research on climate change mitigation.

Improving climate change mitigation analysis: A framework for examining feasibility

Fri, 18 Sep 2020 00:00:00 +0000

Limiting global warming to 2\degree {=latex}C or less compared with pre-industrial temperatures will require unprecedented rates of decarbonization globally. The scale and scope of transformational change required across sectors and actors in society raises critical questions of feasibility. Much of the literature on mitigation pathways addresses technological and economic aspects of feasibility, but overlooks the behavioral, cultural, and social factors that affect theoretical and practical mitigation pathways. We present a tripartite framework that "unpacks" the concept of mitigation pathways by distinguishing three factors that together determine actual mitigation: technical potential, initiative feasibility, and behavioral plasticity. The framework aims to integrate and streamline heterogeneous disciplinary research traditions toward a more comprehensive and transparent approach that will facilitate learning across disciplines and enable mitigation pathways to more fully reflect available knowledge. We offer three suggestions for integrating the tripartite framework into current research on climate change mitigation.

The new revolving door

Tue, 08 Sep 2020 00:00:00 +0000

This Article demonstrates that a new revolving door is emerging between environmental-advocacy groups and the private sector. Since the birth of the modern regulatory state, scholars have raised concerns that the revolving door between corporations and government agencies could induce government officials to pursue corporate interests rather than the public interest. The legal and political-science literatures have identified several benefits that may arise from the revolving door, but the thrust of the scholarship to date has emphasized the potential harms. Using several data sources, we demonstrate that as the private sector has begun to play an increasing role in environmental governance in recent years, a new revolving door has emerged between environmental-advocacy groups and corporations, institutional investment firms, and private equity firms. We demonstrate that this new revolving door is surprisingly common, and we examine the implications for the future of public and private environmental governance. Although this new revolving door creates new risks, we argue that it may turn on its head the central concern about the revolving door: The movement of environmental advocates into corporate management positions may play the role of greening corporate behavior and may accelerate the development of private environmental initiatives. We focus on the movement of employees in the environmental area—a new green revolving door—but we suggest that this new revolving door also may be emerging in labor, health and safety, and other regulatory areas.

All That Performative Environnmentalism Adds Up

Sat, 31 Aug 2019 00:00:00 +0000

Annie Lowery has a new article in The Atlantic, “All That Performative Environmentalism Adds Up,” in which she considers the ways in which actions by individuals and households can play important roles in promoting effective policy actions to reduce greenhouse gas emissions.

What communities do, laws reflect—this is another reason to act on climate change, and urgently. “We’re part of a society, where people interact with companies, companies interact with the government, and people interact with the government. And in all of these cases, the interactions go both ways,” Jonathan Gilligan, a physicist and a climate-change researcher at Vanderbilt University, told me. “Each part influences another.” Many climate activists believe that changing social norms around carbon-intensive behaviors makes the likelihood of dramatic climate-change legislation in the future more likely, not less.

Climate and Society: Drowning Cities

Sun, 06 Sep 2020 00:00:00 +0000

This interdisciplinary class will explore legendary floods and the physical and cultural phenomena of the world’s “drowning cities,” bringing together diverse perspectives from environmental science and the history of architecture, engineering, and urbanism."

A framework for assessing the impact of private climate governance

Sat, 01 Feb 2020 00:00:00 +0000

The growing sense of urgency by the public for action to address climate change stands in stark contrast to the slow pace and limited accomplishments of national and international institutions to reduce greenhouse gas emissions. Political institutions face significant structural barriers to taking strong and rapid action to cut emissions, but private environmental governance has potential to avoid those barriers and achieve rapid emissions reductions. It appears unlikely that private governance alone can reduce emissions enough to stabilize the climate, but it does have the potential to reduce emissions sufficiently and quickly enough to buy time for enacting more comprehensive public governance measures. In this Perspective, we review what is known about private governance, present a framework for analyzing private governance initiatives, outline the prospects of the framework for understanding and guiding private governance, and identify future research priorities for applying this framework.

Eight grand challenges in socio-environmental systems modeling

Sat, 01 Feb 2020 00:00:00 +0000

Modeling is essential to characterize and explore complex societal and environmental issues in systematic and collaborative ways. Socio-environmental systems (SES) modeling integrates knowledge and perspectives into conceptual and computational tools that explicitly recognize how human decisions affect the environment. Depending on the modeling purpose, many SES modelers also realize that involvement of stakeholders and experts is fundamental to support social learning and decision-making processes for achieving improved environmental and social outcomes. The contribution of this paper lies in identifying and formulating grand challenges that need to be overcome to accelerate the development and adaptation of SES modeling. Eight challenges are delineated: bridging epistemologies across disciplines; multi-dimensional uncertainty assessment and management; scales and scaling issues; combining qualitative and quantitative methods and data; furthering the adoption and impacts of SES modeling on policy; capturing structural changes; representing human dimensions in SES; and leveraging new data types and sources. These challenges limit our ability to effectively use SES modeling to provide the knowledge and information essential for supporting decision making. Whereas some of these challenges are not unique to SES modeling and may be pervasive in other scientific fields, they still act as barriers as well as research opportunities for the SES modeling community. For each challenge, we outline basic steps that can be taken to surmount the underpinning barriers. Thus, the paper identifies priority research areas in SES modeling, chiefly related to progressing modeling products, processes and practices.

Data Science Methods for Smart City Applications

Tue, 13 Jun 2017 00:00:00 +0000

A University Course offered under the auspices of the Vanderbilt Strategic Plan, this team-taught, project-based course will integrate technological and socio-economic approaches to challenges facing metropolitan areas experiencing unprecedented growth. It will address the infrastructure and resources needed for sustainable development and to maintain quality of life.

Avoiding "day-zero": A testbed for evaluating integrated food-energy-water management in Cape Town, South Africa

Tue, 31 Dec 2019 00:00:00 +0000

Deep connections between water resources and food and energy production—the food-energy-water (FEW) nexus—complicate the challenge of sustainably managing an uncertain water supply. We present an agent-based model as a computational testbed for studying different approaches to managing the FEW nexus and apply the model to the 2017–2018 water crisis in Cape Town South Africa. We treat the FEW nexus connecting municipal water use by Cape Town residents, agricultural water use by vineyards, and hydroelectric generation. We compare two scenarios for responding to drought: business-as-usual (BAU), and holistic adaptive management (HAM), where BAU takes no action until the monthly supply is insufficient to meet demand, whereas HAM takes action by raising water tariffs when the reservoir storage level drops below its pre-drought monthly average. Simulation results suggest that holistic adaptive management can alleviate the impact of drought on agricultural production, hydropower generation, and the availability of water for residential consumption.

A Framework for Assessing Private Climate Governance

Mon, 23 Dec 2019 00:00:00 +0000

Mike Vandenbergh and I have a new paper out, in the journal Energy Research & Social Science, on our three-part framework for assessing the impacts of private climate governance.

We discussed our three-part framework in previous writing, such as “Accounting for Political Feasibility”, “Beyond Gridlock”, and Beyond Politics. Here, we discuss some practical steps toward applying the framework to assessing the prospects and potential impacts of private climate governance and some of the research needs and priorities for using our framework more broadly.

Beyond Politics is one of the top environmental books of the last 50 years

Mon, 23 Dec 2019 00:00:00 +0000

My book, Beyond Politics was included in a list of the top environmental books of the last 50 years in a retrospective by Oliver A. Houck and G Tracy Mehan in Environmental Forum, published by the Environmental Law Institute.

Short film on my Bangladesh research

Tue, 10 Dec 2019 00:00:00 +0000

A short film about my collaborative interdisciplinary research project in Bangladesh is featured at the AGU Cinema at the 2019 Fall Meeting of the American Geophysical Union, and is also available on YouTube. The film, by Andre Leroux, focuses on interdisciplinary research on the changing river systems of Bangladesh and the prospect of sustainably managing the delta in the face of climate change and sea-level rise.

Modelling diet choices

Fri, 09 Aug 2019 00:00:00 +0000

Meat is an important source of greenhouse-gas emissions, but not enough people are giving it up. A new model integrates diets, land use and climate change to explore the potential and implications of mass adoption of vegetarian diets.

This past winter in Nashville was unusually warm and rainy. And it looks like spring will be, too.

Wed, 20 Mar 2019 00:00:00 +0000

I was quoted in a story at the Tennessean about the unusually warm and wet winter in 2018–19: “Winters have gotten so warm in the last 20 or so years that people forget. Weather that wouldn’t have been remarkably cold 30 or 40 years ago seems extraordinarily cold today.”

Bangladesh's geography will naturally counter sea level rise until it becomes too rapid due to climate change

Tue, 19 Feb 2019 00:00:00 +0000

I was interviewed by the Dhaka Tribune on the impact of sea-level rise in Bangladesh. I explained that with good land-management, sediment carried to the coast by the Ganges, Brahmaputra, and Meghna rivers can raising the land as fast as the sea is rising for the near-future, but that eventually global warming may cause the sea level to rise faster than the land can adapt.

Carrots and sticks in private climate governance

Mon, 31 Dec 2018 00:00:00 +0000

When public governance fails to address important environmental threats—such as climate change—private governance by firms, not-for-profits, individuals, and households can produce significant reductions in greenhouse gas emissions. Private governance can take the form of either a carrot or a stick, using incentives or punishments. Shareholder activism as a form of private governance of corporations has largely been confrontational, leading most climate-related actions to fail. This Article examines the potential for private governance to take a more collaborative approach and to frame shareholder engagement with management in terms of opportunity. It also examines private governance successes at reducing household emissions and finds that these too emphasize making it attractive and convenient for households to act.

Good Law | Bad Law Podcast

Fri, 21 Dec 2018 00:00:00 +0000

Michael Vandenbergh and I were interviewed by Aaron J. Freiwald for the Good Law/Bad Law podcast. We discussed our recent book and the role of the private sector in reducing greenhouse gas emissions.

Topic modeling the president: Conventional and computational methods

Sat, 06 Oct 2018 00:00:00 +0000

Law is generally represented through text, and lawyers have for centuries classified large bodies of legal text into distinct topics — they "topic model" the law. But large bodies of legal documents present challenges for conventional topic modeling methods. The task of gathering, reviewing, coding, sorting, and assessing a body of tens of thousands of legal documents is a daunting proposition. Recent advances in computational text analytics, a subset of the field of "artificial intelligence," are already gaining traction in legal practice settings such as e-discovery by leveraging the speed and capacity of computers to process enormous bodies of documents. Differences between conventional and computational methods, however, suggest that computational text modeling has its own limitations, but that the two methods used in unison could be a powerful research tool for legal scholars in their research as well.

Beyond Politics Webinar at the Environmental Law Institute

Sat, 01 Dec 2018 00:00:00 +0000

Michael Vandenbergh and I participated in a webinar hosted by the Environmental Law Institute on our book, Beyond Politics: The Private Governance Response to Climate Change. Cassie Phillips (director of the Private Environmental Governance Initiative at ELI) moderated. Stephen Harper (Global Director of Environment and Energy Policy at Intel) and Jackie Roberts (Chief Sustainability Officer at the Carlisle Group) provided private industry perspectives.

Employee energy benefits: What are they and what effects do they have on employees?

Tue, 07 Aug 2018 00:00:00 +0000

Employee energy benefits (EEBs), such as subsidies for employee home energy audits and financial incentives for carpooling to work, aim to influence employees' environmental behaviors outside of work. Exploring these understudied benefits would offer new insights that can enrich theories of employer and employee motivations for engaging in environmental behavior, as well as reveal new strategies for making significant progress on environment goals. By drawing upon employer reports and conducting a survey of 482 US adults employed full-time, we found that there are a wide range of types of EEBs currently offered by employers, and furthermore, they were more likely to be offered in certain industries, such as state and local governments but not others such as retail. These benefits were offered to 17% of employees and included a vast array of strategies and approaches. Guided by theorizing on employer and employee motivation, open-ended responses suggested employers were perceived to offer EEBs to maximize competiveness and because of social responsibility concerns, and employees tended to enroll because they wanted to save money and time or because they cared about the environment. Finally, EEBs were linked to employee environmental behavior and morale. The findings reveal new information about the types of EEBs being offered, motivations for offering and enrolling in EEBs, and their relationship to employee behavior and morale. This work suggests numerous lines of promising new research.

New paper on employers who offer energy efficiency benefits to their employees

Tue, 07 Aug 2018 00:00:00 +0000

I have a new paper in the journal Energy Efficiency, co-authored with Alex Maki, Emmett McKinney, Mike Vandenbergh, and Mark Cohen, about employers who offer employee benefits to promote energy efficiency.

Radio interview about water conservation policies

Mon, 06 Aug 2018 00:00:00 +0000

I was interviewed for The Show on KJZZ in Phoenix about my recent paper on urban water conservation policies in the U.S.

Workshop on River Navigability and Inland Shipping in Bangladesh

Fri, 27 Jul 2018 00:00:00 +0000

Workshop on River Navigability and Inland Shipping in Bangladesh: Economic Importance and Impacts of Environmental Change

On a recent trip to Bangladesh I collaborated with Dr. Bishawjit Mallick (Chair of Environmental Development and Risk Management at Technische Universität Dresden), the environmental activist collective Riverine People, and Professor Md. Monirul Islam at Dhaka University, and representatives of the School of Environmental Science and Management at the Independent University of Bangladesh and the International Centre for Climate Change and Development to organize a workshop on River Navigability and Inland Shipping in Bangladesh with a focus on the economic impact of formal and informal use of inland waterways for passenger and cargo traffic.

Two US Professors meet DU VC

Tue, 10 Jul 2018 00:00:00 +0000

The Financial Express (Bangladesh) reported on the meeting between Prof. Steve Goodbred and myself, from Vanderbilt University, and the Dr. Md. Aktaruzzaman, Vice-Chancellor of Dhaka University. During the meeting, we discussed academic and research collaborations between Dhaka University and Vanderbilt on climate change, riverbank erosion, access to safe drinking water, and other environmental challenges.

Scientific and Informed Research Needed on Waterways

Mon, 09 Jul 2018 00:00:00 +0000

The Daily Samakal (Bangladesh) reported on a workshop I helped to organize in Dhaka on “River Navigation and Inland Shipping in Bangladesh: Economic Importance and Impacts of Environmental Change”. Participants included academics, government officials, representatives of the shipping industry, and members of community and political activist groups.

Political leaning influences city water policies as strongly as climate

Mon, 18 Jun 2018 00:00:00 +0000

Urban water conservation policies are reflecting the nation’s political polarization, with a new report demonstrating that a city’s water ordinances can be as much related to whether it leans left or right as to whether the climate is wet or dry.

Vanderbilt University environmental researchers found Los Angeles ranks No. 1 for number and strength of policies, followed by six other left-leaning California cities along with Austin, Texas. It takes until San Antonio, Texas, at No. 8 to find a right-leaning city with strong water conservation policies—probably because the amount of water it can withdraw from the Edwards Aquifer is strictly limited, said the study’s lead author, Jonathan Gilligan, associate professor of earth and environmental sciences.

Urban water conservation policies in the United States

Tue, 12 Jun 2018 00:00:00 +0000

Urban water supply systems in the United States are increasingly stressed as economic and population growth confront limited water resources. Demand management, through conservation and improved efficiency, has long been promoted as a practical alternative to building Promethean energy-intensive water-supply infrastructure. Some cities are making great progress at managing their demand, but study of conservation policies has been limited and often regionally focused. We present a hierarchical Bayesian analysis of a new measure of urban water conservation policy, the Vanderbilt Water Conservation Index (VWCI), for 195 cities in 45 states in the contiguous United States. This study does not attempt to establish causal relationships, but does observe that cities in states with arid climates tend to adopt more conservation measures. Within a state, cities with more Democratic-leaning voting preferences and large and rapidly growing populations tend to adopt more conservation measures. Economic factors and climatic differences between cities do not correlate with the number of measures adopted, but they do correlate with the character of the measures, with arid cities favoring mandatory conservation actions and cities in states with lower real personal income favoring rebates for voluntary actions. Understanding relationships between environmental and societal factors and cities' support for water conservation measures can help planners and policy-makers identify obstacles and opportunities to increase the role of conservation and efficiency in making urban water supply systems sustainable.

Urban Water Conservation Policies in the United States

Tue, 12 Jun 2018 00:00:00 +0000

Cities face challenges on many fronts as they work to assure their residents of safe and reliable access to water. Changes in both supply and demand are driven by complex interactions among many human and natural factors, such as drought, infrastructure, population growth, and land-use. Climate change adds new complexities and uncertainties as cities plan for the future. In the past, challenges to water security were addressed by Promethean energy- and technology-intensive infrastructure projects, such as long-distance transfers, desalination, and artificial aquifer recharge; but in recent years, attention to soft approaches has grown. Soft approaches to water security focus on improving efficiency in obtaining and consuming water, and as John Fleck documented in his book, Water Is for Fighting Over, a number of cities have made impressive progress toward resilience and sustaniability.

My book reviewed in Nature Climate Change

Tue, 27 Feb 2018 00:00:00 +0000

Time to Re-Think Solutions

For people working to address climate change, there is certainly no viable alternative to reading this book. Beyond Politics presses readers to think beyond their current conception of climate change solutions and, while laying out a reasoned private governance response accompanied by a realistic assessment of its limitations, provides the groundwork for future research and initiatives to reduce emissions.

Dangerous Assumptions Revisited

Tue, 13 Feb 2018 00:00:00 +0000

Comparisons of observed trends of energy and carbon intensity in the global economy to trends implied by emissions scenarios used in policy analysis suggested that those scenarios were severely over-optimistic about the rate at which the world would spontaneously decarbonize its economy.

I update these analysis, using global emissions since 2005, and find that observed rates of decarbonization are not far behind those implied by the RCP 4.5 policy scenario. This suggests that the policy challenge may not be as difficult as previous work has reported.

A machine-learning approach to forecasting remotely sensed vegetation health

Mon, 01 Jan 2018 00:00:00 +0000

Drought threatens food and water security around the world, and this threat is likely to become more severe under climate change. High-resolution predictive information can help farmers, water managers, and others to manage the effects of drought. We have created an open-source tool to produce short-term forecasts of vegetation health at high spatial resolution, using data that are global in coverage. The tool automates downloading and processing Moderate Resolution Imaging Spectroradiometer (MODIS) data sets and training gradient-boosted machine models on hundreds of millions of observations to predict future values of the enhanced vegetation index. We compared the predictive power of different sets of variables (MODIS surface reflectance data and Level-3 MODIS products) in two regions with distinct agro-ecological systems, climates, and cloud coverage: Sri Lanka and California. Performance in California is higher because of more cloud-free days and less missing data. In both regions, the correlation between the actual and model predicted vegetation health values in agricultural areas is above 0.75. Predictive power more than doubles in agricultural areas compared to a baseline model.

Climate modeling: Accounting for the human factor

Mon, 01 Jan 2018 00:00:00 +0000

One of the greatest sources of uncertainty about future climate change is the path greenhouse gas emissions will take. Now research using a coupled model of human behaviour and climate finds that individual behaviour can significantly alter emissions trajectories and global temperature.

Dialogue: Beyond politics: The private governance response to climate change

Mon, 01 Jan 2018 00:00:00 +0000

When the United States withdrew from the Paris Climate Agreement, 100 private corporations reaffirmed their commitment to fighting climate change. While governments are often tasked with facing climate change, many major private institutions are taking steps to significantly reduce carbon emissions, reaping the benefits of favorable public image and reduced operational costs from energy and other savings. On September 5, 2018, ELI held an expert panel discussing the role of private institutions in climate change mitigation, the incentives for private actors pursuing carbon reduction initiatives, key factors in successful case studies, and methods for developing and evaluating successful private climate initiatives. Below, we present a transcript of the discussion, which has been edited for style, clarity, and space considerations.

Widespread infilling of tidal channels and navigable waterways in the human-modified tidal deltaplain of southwest Bangladesh

Wed, 27 Dec 2017 00:00:00 +0000

Since the 1960s, $\sim 5000~\text{km}^2$ of tidal deltaplain in southwest Bangladesh has been embanked and converted to densely inhabited, agricultural islands (i.e., polders). This landscape is juxtaposed to the adjacent Sundarbans, a pristine mangrove forest, both well connected by a dense network of tidal channels that effectively convey water and sediment throughout the region. The extensive embanking in poldered areas, however, has greatly reduced the tidal prism (i.e., volume of water) transported through local channels. We reveal that $>600~\text{km}$ of these major waterways have infilled in recent decades, converting to land through enhanced sedimentation and the direct blocking of waterways by embankments and sluice gates. Nearly all of the observed closures ($\sim 98%$) have occurred along the embanked polder systems, with no comparable changes occurring in channels of the Sundarbans ($<2%$ change). We attribute most of the channel infilling to the local reduction of tidal prism in poldered areas and the associated decline in current velocities. The infilled channels account for $\sim 90~\text{km}^2$ of new land in the last 40–50 years, the rate of which, $\sim 2~\text{km}^2/\text{yr}$, offsets the $4~\text{km}^2/\text{yr}$ that is eroded at the coast, and is equivalent to $\sim 20%$ of the new land produced naturally at the Ganges-Brahmaputra tidal rivermouth. Most of this new land, called 'khas' in Bengali, has been reclaimed for agriculture or aquaculture, contributing to the local economy. However, benefits are tempered by the loss of navigable waterways for commerce, transportation, and fishing, as well as the forced rerouting of tidal waters and sediments necessary to sustain this low-lying landscape against rising sea level. A more sustainable delta will require detailed knowledge of the consequences of these hydrodynamic changes to support more scientifically-grounded management of water, sediment, and tidal energy distribution.

My Book Reviewed in Science Magazine

Mon, 18 Dec 2017 00:00:00 +0000

Faced with Government Inaction, Private Firms Emerge as Major Players in Climate Mitigation

In a thoughtful and far-ranging new book, Michael P. Vandenbergh and Jonathan M. Gilligan turn that view upside down. Both from Vanderbilt University—Vandenbergh a lawyer and Gilligan a professor of civil and environmental engineering—the authors help explain why firms from Coca-Cola to UPS are motivated to be leaders in cutting emissions.

Beyond Politics: Private industry needs to step up on climate change

Tue, 05 Dec 2017 00:00:00 +0000

When the United States pulled out of the Paris Climate Agreement, environmentalists were disappointed, but then businesses stepped up on their own to fight global warming. Two Vanderbilt experts say evidence shows that progress can continue to be made regardless of what the government is doing.

Beyond politics: The private governance response to climate change

Thu, 30 Nov 2017 00:00:00 +0000

Private sector action provides one of the most promising opportunities to reduce the risks of climate change, buying time while governments move slowly or even oppose climate mitigation. Starting with the insight that much of the resistance to climate mitigation is grounded in concern about the role of government, this books draws on law, policy, social science, and climate science to demonstrate how private initiatives are already bypassing government inaction in the US and around the globe. It makes a persuasive case that private governance can reduce global carbon emissions by a billion tons per year over the next decade. Combining an examination of the growth of private climate initiatives over the last decade, a theory of why private actors are motivated to reduce emissions, and a review of viable next steps, this book speaks to scholars, business and advocacy group managers, philanthropists, policymakers, and anyone interested in climate change.

Are Cops on the Science Beat?

Sun, 01 Oct 2017 00:00:00 +0000

NSF awards $13 million for research on how humans, environment interact

Tue, 12 Sep 2017 00:00:00 +0000

My new research project in Bangladesh, with Kimberly Rogers, Amanda Carrico, Katharine Donato, and Carol Wilson, was featured in the National Science Foundation’s announcement of this year’s grants for research on coupled human-natural systems.

The Science Police

Sat, 01 Jul 2017 00:00:00 +0000

I was quoted by Keith Kloor in an article in Issues in Science and Technology about the breakdown of civility in environmental science.

Government action isn't enough for climate change: The private sector can cut billions of tons of carbon

Wed, 21 Jun 2017 00:00:00 +0000

With President Trump’s announcement to pull the United States out of the Paris Agreement, many other countries around the world—and cities and states within the U.S.—are stepping up their commitments to address climate change.

But one thing is clear: Even if all the remaining participating nations do their part, governments alone can’t substantially reduce the risk of catastrophic climate change.

Private industry, better messaging can help overcome damage from Paris withdrawal

Fri, 02 Jun 2017 00:00:00 +0000

President Donald Trump’s announcement on Thursday that the U.S. will withdraw from the Paris Climate Agreement phases out U.S. commitments to achieve carbon reduction targets and make financial contributions to slow climate change.

It was a move environmentalists found disappointing, at best. But Vanderbilt University law and earth science professors contend initiatives that reduce carbon emissions from corporations and households can fill some of the gap.

They point to the example of Walmart, which reduced carbon emissions worldwide by more than 20 million metric tons by focusing on efficiency in its global supply chain. Google agreed to locate its massive data center in Clarksville, Tennessee, only after the Tennessee Valley Authority agreed to supply it with renewable power.

Vanderbilt researchers studying Bangladesh for harbinger of climate change impact

Fri, 02 Jun 2017 00:00:00 +0000

Bangladesh uniquely interests U.S. climate change researchers for a pair of reasons: Its place on the globe makes it particularly vulnerable to devastating weather events, and it’s a predominantly Muslim nation that maintains a secular, pro-Western outlook.

Vanderbilt University’s Jonathan Gilligan, associate professor of earth and environmental sciences, Steven Goodbred, professor of earth and environmental sciences, Brooke Ackerly, professor of political science, and their team travel there frequently though funding from the Office of Naval Research, The National Science Foundation, and other agencies, using Bangladesh as a climate change harbinger for our own coastal regions. Particularly evident is the way land use mismanagement, similar to what happens here, has affected flooding.

National assessment overstates public access to safe drinking water in Bangladesh

Tue, 16 May 2017 00:00:00 +0000

Far fewer people in Bangladesh have safe water than the state government has estimated, new research shows. In addition, many people who do not have access to safe drinking water are under the mistaken impression that their water is safe, drinkable, and clean.

According to the latest national assessment, 85 percent of the people in Bangladesh have access to safe drinking water. However, the new research uncovers two major problems that the national statistics don’t reflect.

Gilligan, Vandenbergh win Morrison Prize for climate change article

Thu, 09 Feb 2017 00:00:00 +0000

Research examining the role that private governance can play in bypassing government gridlock on climate change has earned a pair of Vanderbilt University professors this year’s $10,000 Morrison Prize, which recognizes the most impactful sustainability-related legal academic article published in North America during the previous year.

Michael P. Vandenbergh and Jonathan Gilligan were recognized for their paper, “Beyond Gridlock,” which was published in the Columbia Journal of Environmental Law. They will present the paper at the Third Annual Sustainability Conference of American Legal Educators, held in May at the Sandra Day O’Connor College of Law at Arizona State University. The Morrison Prize, which is administered through the O’Connor College of Law’s Program on Law and Sustainability, is named for its funder, Richard N. Morrison, co-founder of Arizona State’s Morrison Institute for Public Policy.

Morrison Prize

Thu, 09 Feb 2017 00:00:00 +0000

The Program on Law and Sustainability at the Sandra Day O’Connor College of Law at Arizona State University has awarded the Morrison Prize to Mike Vandenbergh and me for our article “Beyond Gridlock,” 40 Columbia Environmental Law Journal, 217–303 (2015). The Morrison prize recognizes the paper published in the previous year in North America that is “likely to have the most significant positive long-term impact on the advancement of the environmental sustainability movement.”

Are cops on the science beat?

Sun, 01 Jan 2017 00:00:00 +0000

Keith Kloor raises important concerns, but is not able to arrive at a clear conclusion about what, if anything, ought to be done about those problems. Though he presents a handful of alarming anecdotes, he cannot say whether these represent the exception or the rule, and it makes a difference whether scientific discourse mostly works, with a few glaring exceptions, or is pervasively broken.Real life does not distinguish as clearly as Kloor attempts to do between scientific and ideological considerations. The article by Roger Pielke in FiveThirtyEight, which Kloor discusses at length, certainly attracted ideological responses, but it was also widely criticized on scientific grounds. Pielke and his critics, such as William Nordhaus, have published arguments for and against in peer-reviewed journals. For those who sincerely believe that someone's methods are deeply flawed and his or her conclusions factually incorrect, it is not an act of censorship, but of responsible peer review or journalism to not print that work. To do otherwise risks contributing to the phenomenon Maxwell Boykoff and Jules Boykoff call "Balance as Bias."

Climate and community: The human rights, livelihood, and migration impacts of climate change

Sun, 01 Jan 2017 00:00:00 +0000

Climate change is a global problem. Food, water, health, housing, and life are basic individual human rights. However, between the global forces of climate change and individual challenges of meeting basic needs, communities are the context in which people experience the effects of climate change and seek to adapt to its impact on their livelihoods. Such adaptation may include permanent migration and certainly, this has been one of the foci of international relations and security politics related to climate change. Of course, such migration will have human rights consequences and there are human rights causes to some of this migration as well. Of equal importance, but gaining less attention, are the problems related to climate change effects that do not cause mass migration, that may include short-term seasonal migration, and that also have human rights causes and consequences. In this chapter, we use a study in rural Bangladesh to demonstrate the import of the human rights considerations of this second, community-level, impact of climate change on human rights. We find that the human rights impacts of slow and rapid onset environmental change are a function of democratic, social, and economic rights, that is, those human rights that are best understood as enjoyed through political community are equally worthy of our rights attention because they are essential to climate change adaptation.

Nature of collaboration across disciplines

Sun, 01 Jan 2017 00:00:00 +0000

I have been fortunate to have witnessed a complete transformation of the nature of collaboration across disciplines over the course of my career. As a graduate student in Physics, I did my doctoral research in an interdisciplinary laser spectroscopy laboratory established by my adviser and two chemists. My interests were primarily in performing spectroscopy on small molecules precisely enough to test theoretical predictions of quantum electrodynamic effects in the hydrogen molecule, while the chemists used much of the same equipment to study larger molecules. The intellectual atmosphere of the laboratory was fascinating, and the daily conversations across our similar but distinct disciplines gave me a taste that I never lost for seeking out ways in which I can learn new perspectives on the problems I am working on by discussing them with people in different disciplines. However, despite a productive research effort that brought in substantial funding and produced a steady stream of publications in major physics and chemistry journals, my adviser's tenure case was hindered by the perception in the two departments that he was doing too much physics to be a chemist and too much chemistry to be a physicist. More broadly, the challenge of interdisciplinary research was a frequent topic of discussion in the American Physical Society and the American Chemical Society, with broad agreement that such research held great promise for advancing the frontiers of knowledge, but most senior members concluded that it was too politically risky for junior faculty to attempt, and should be left until after achieving tenure.

Spatiotemporal patterns of agricultural drought in Sri Lanka: 1881--2010

Mon, 01 Feb 2016 00:00:00 +0000

A spatiotemporal analysis of two well-known agricultural drought indices, the Palmer Drought Severity Index (PDSI) and the Standardized Precipitation Index at a 9-month scale (SPI-9), is presented for Sri Lanka. The analysis was conducted based on monthly precipitation and temperature data from January 1881 to December 2010 using 13 stations distributed across the three climatic zones of the country. Principal component analysis shows that the first two principal components of PDSI and SPI-9 are spatially comparable and could physically represent the two main monsoons. A wavelet analysis of these principal components' scores for both indices indicates a stronger association between the Northeastern monsoon and El-Niño in recent decades. Correlation analysis with agricultural metrics suggests that different indices might be appropriate for each of the climatic zones in Sri Lanka. PDSI correlated best with the intermediate zone districts; SPI-9 correlated best with the dry zone districts; but neither index correlated well with the wet zone districts.

Agricultural adaptation to drought in the Sri Lankan dry zone

Fri, 01 Jan 2016 00:00:00 +0000

Droughts affect more people than any other natural disaster. Drought severity is not merely a function of precipitation; it emerges from a web of interrelations between human and natural systems. The impacts of drought are equally complex, shifting across temporal scales, economic sectors, and regions. Even in regions with similar hydroclimatic characteristics, there is tremendous variation in the effects of drought. This study combines satellite imagery, geospatial data, and qualitative data to identify the multi-scalar factors that drive variations in agricultural responses to drought. We analyzed eleven years of remotely sensed imagery to identify agricultural areas in which cultivation occurred during an extreme drought in Sri Lanka. We visited a subset of these communities and conducted interviews with officials and farmers to identify the factors that influenced agricultural adaptation. Results suggest that though structural factors such as infrastructural capacity and physical environment significantly affect agricultural adaptation, dynamic factors such as local control of water supply, perceived risk, community cohesion, and farmer experience explain significant variation in the adaptive capacity of agricultural systems.

Application of machine learning to the prediction of vegetation health

Fri, 01 Jan 2016 00:00:00 +0000

This project applies machine learning techniques to remotely sensed imagery to train and validate predictive models of vegetation health in Bangladesh and Sri Lanka. For both locations, we downloaded and processed eleven years of imagery from multiple MODIS datasets which were combined and transformed into two-dimensional matrices. We applied a gradient boosted machines model to the lagged dataset values to forecast future values of the Enhanced Vegetation Index (EVI). The predictive power of raw spectral data MODIS products were compared across time periods and land use categories. Our models have significantly more predictive power on held-out datasets than a baseline. Though the tool was built to increase capacity to monitor vegetation health in data scarce regions like South Asia, users may include ancillary spatiotemporal datasets relevant to their region of interest to increase predictive power and to facilitate interpretation of model results. The tool can automatically update predictions as new MODIS data is made available by NASA. The tool is particularly well-suited for decision makers interested in understanding and predicting vegetation health dynamics in countries in which environmental data is scarce and cloud cover is a significant concern.

Betting and belief: Prediction markets and attribution of climate change

Fri, 01 Jan 2016 00:00:00 +0000

Despite much scientific evidence, a large fraction of the American public doubts that greenhouse gases are causing global warming. We present a simulation model as a computational test-bed for climate prediction markets. Traders adapt their beliefs about future temperatures based on the profits of other traders in their social network. We simulate two alternative climate futures, in which global temperatures are primarily driven either by carbon dioxide or by solar irradiance. These represent, respectively, the scientific consensus and a hypothesis advanced by prominent skeptics. We conduct sensitivity analyses to determine how a variety of factors describing both the market and the physical climate may affect traders' beliefs about the cause of global climate change. Market participation causes most traders to converge quickly toward believing the "true" climate model, suggesting that a climate market could be useful for building public consensus.

Drinking water insecurity: Water quality and access in coastal south-western Bangladesh

Fri, 01 Jan 2016 00:00:00 +0000

National drinking water assessments for Bangladesh do not reflect local variability, or temporal differences. This paper reports on the findings of an interdisciplinary investigation of drinking water insecurity in a rural coastal south-western Bangladesh. Drinking water quality is assessed by comparison of locally measured concentrations to national levels and water quality criteria; resident's access to potable water and their perceptions are based on local social surveys. Residents in the study area use groundwater far less than the national average; salinity and local rainwater scarcity necessitates the use of multiple water sources throughout the year. Groundwater concentrations of arsenic and specific conductivity (SpC) were greater than surface water (pond) concentrations; there was no statistically significant seasonal difference in mean concentrations in groundwater, but there was for ponds, with arsenic higher in the dry season. Average arsenic concentrations in local water drinking were 2–4 times times the national average. All of the local groundwater samples exceeded the Bangladesh guidance for SpC, although the majority of residents surveyed did not perceive their water as having a "bad" or "salty" taste.

Drought, risk, and institutional politics in the American Southwest

Fri, 01 Jan 2016 00:00:00 +0000

Although there are multiple causes of the water scarcity crisis in the American Southwest, it can be used as a model of the long-term problem of freshwater shortages that climate change will exacerbate. We examine the water-supply crisis for 22 cities in the extended Southwest of the United States and develop a unique, new measure of water conservation policies and programs. Convergent qualitative and quantitative analyses suggest that political conflicts play an important role in the transition of water-supply regimes toward higher levels of demandreduction policies and programs. Qualitative analysis using institutional theory identifies the interaction of four types of motivating logics—development, rural preservation, environmental, and urban consumer—and shows how demand-reduction strategies can potentially satisfy all four. Quantitative analysis of the explanatory factors for the variation in the adoption of demand-reduction policies points to the overwhelming importance of political preferences as defined by Cook's Partisan Voting Index. We suggest that approaches to water-supply choices are influenced less by direct partisan disagreements than by broad preferences for a development logic based on supplyincrease strategies and discomfort with demand-reduction strategies that clash with conservative beliefs.

Dynamics of individual and collective agricultural adaptation to water scarcity

Fri, 01 Jan 2016 00:00:00 +0000

Drought and water scarcity are growing challenges to agriculture around the world. Farmers can adapt through both individual and community-based collective actions. We draw on extensive field-work conducted with paddy farmers in rural Sri Lanka to study adaptations to water scarcity, including switching to less water-intensive crops, farming collectively on shared land, and individually turning to groundwater by digging wells. We explore how variability in climate affects agricultural decision-making at the community and individual levels using three types of decision-making, each characterized by an objective function: risk-averse expected utility, regret-adjusted expected utility, and prospect theory loss-aversion. We also assess how the introduction of individualized access to irrigation water with wells affects community-based drought mitigation practices. Preliminary results suggest that the growth of well-irrigation may produce sudden disruptions to community-based adaptations, but that this depends on the mental models farmers use to think about risk and make decisions under uncertainty.

Beyond gridlock