Equity and modeling in sustainability science: Examples and opportunities throughout the process.

Equity is core to sustainability, but current interventions to enhance sustainability often fall short in adequately addressing this linkage. Models are important tools for informing action, and their development and use present opportunities to center equity in process and outcomes. This Perspective highlights progress in integrating equity into systems modeling in sustainability science, as well as key challenges, tensions, and future directions. We present a conceptual framework for equity in systems modeling, focused on its distributional, procedural, and recognitional dimensions. We discuss examples of how modelers engage with these different dimensions throughout the modeling process and from across a range of modeling approaches and topics, including water resources, energy systems, air quality, and conservation. Synthesizing across these examples, we identify significant advances in enhancing procedural and recognitional equity by reframing models as tools to explore pluralism in worldviews and knowledge systems; enabling models to better represent distributional inequity through new computational techniques and data sources; investigating the dynamics that can drive inequities by linking different modeling approaches; and developing more nuanced metrics for assessing equity outcomes. We also identify important future directions, such as an increased focus on using models to identify pathways to transform underlying conditions that lead to inequities and move toward desired futures. By looking at examples across the diverse fields within sustainability science, we argue that there are valuable opportunities for mutual learning on how to use models more effectively as tools to support sustainable and equitable futures.

Utility disconnection protections and the incidence of energy insecurity in the United States.

Energy insecurity-the inability to secure one's energy needs-impacts millions of Americans each year. A particularly severe instance of energy insecurity is when a utility disconnects a household from service, affecting its ability to refrigerate perishable food, purchase medicine, or maintain adequate temperatures. Governments can protect vulnerable populations from disconnections through policies, such as shutoff moratoria or seasonal protections that limit disconnections during extreme weather months. We take advantage of the temporary disconnection moratoria that states implemented during the COVID-19 pandemic to assess the efficacy of state protections on rates of disconnection, spending across other essential needs, and uptake of bill payment assistance. We find that protections reduce disconnections and the need for households to forgo other expenses. We further find that protections are most beneficial to people of color and households with young children. We conclude with a discussion of the policy implications for energy-insecure populations.

Mapping county-level vulnerability to the energy transition in US fossil fuel communities.

The energy transition toward lower-carbon energy sources will inevitably result in socioeconomic impacts on certain communities, particularly those that have historically produced fossil fuel resources and electricity generation using fossil fuels. Such communities stand to lose jobs, tax revenues, and support for public services. Which communities are most likely to be affected, which are more susceptible to being harmed, and how to target adaptive capacity programs-such as economic development and workforce training-accordingly are pressing scholarly and policy questions. In this study, we apply a vulnerability framework to calculate, rank, and map exposure and sensitivity scores for fossil fuel producing regions in the US. We find that, while counties in most regions of the United States will be affected by the transition away from fossil fuels, counties in Appalachia, Texas and the Gulf Coast region, and the Intermountain West are likely to experience the most significant impacts, and some regions experience overlapping and significant incidence of vulnerability. These results can be used to target future adaptive capacity programs.

Behavioral and financial coping strategies among energy-insecure households.

When households struggle to pay their energy bills and avoid being disconnected from the grid, they may accrue debt, forgo expenses on food, and use space heaters or ovens to warm their homes. These coping strategies can introduce significant physical and financial risks. In this study, we analyze an original survey with a representative sample of low-income households during the first year of the COVID-19 pandemic, from June 2020 to May 2021. We evaluate the prevalence of a wide range of coping strategies and empirically estimate the determinants of these strategies. We find that more than half of all low-income households engage in at least one coping strategy, and many use multiple strategies. Households with vulnerable members, including young children or those who rely on electronic medical devices, and households that live in deficient housing conditions, are more likely to use a range of coping strategies, and many at once. Our findings have direct implications for public policy improvements, including modifications to the US Weatherization Assistance Program, the Low-Income Home Energy Assistance Program, and state utility disconnection protections.

Equity, technological innovation and sustainable behaviour in a low-carbon future.

The world must ambitiously curtail greenhouse gas emissions to achieve climate stability. The literature often supposes that a low-carbon future will depend on a mix of technological innovation-improving the performance of new technologies and systems-as well as more sustainable behaviours such as travelling less or reducing waste. To what extent are low-carbon technologies, and their associated behaviours, currently equitable, and what are potential policy and research implications moving forward? In this Review, we examine how four innovations in technology and behaviour-improved cookstoves and heating, battery electric vehicles, household solar panels and food-sharing-create complications and force trade-offs on different equity dimensions. We draw from these cases to discuss a typology of inequity cutting across demographic (for example, gender, race and class), spatial (for example, urban and rural divides), interspecies (for example, human and non-human) and temporal (for example, future generations) vulnerabilities. Ultimately, the risk of inequity abounds in decarbonization pathways. Moreover, low-carbon innovations are not automatically just, equitable or even green. We show how such technologies and behaviours can both introduce new inequalities and reaffirm existing ones. We then discuss potential policy insights and leverage points to make future interventions more equitable and propose an integrated research agenda to supplement these policy efforts.

Are all electrons the same? Evaluating support for local transmission lines through an experiment.

A crucial factor in U.S. energy infrastructure development is the degree to which citizens that reside near a development support or oppose the project. While the literature offers several explanations about what shapes individuals' perceptions of energy projects, few have considered the importance of cognitive heuristics and the law of contagion. Here, we employ a survey experiment on a nationally-representative sample of 2,000 respondents to test whether knowing which energy resources connect to a high-voltage transmission line dictate support for the line. Results reveal that information about the source of electricity is fundamentally important. If a transmission line is said to carry electricity from a solar and wind development, a respondent is significantly more likely to support development of the line. If the line instead is said to carry electricity from a natural gas or coal plant, respectively, respondents are significantly less likely to support it. This study has implications for energy infrastructure development, messaging, and public acceptance of energy projects.

Cost Implications for Automaker Compliance of Zero Emissions Vehicle Requirements.

While there are many automotive regulations in the United States, few studies in the literature examine the interaction between different rules. We investigate the cost implications of enforcing the national Corporate Average Fuel Economy (CAFE) and greenhouse gas (GHG) emissions standards and the Zero Emissions Vehicle (ZEV) requirements simultaneously. We construct a new "Cost Optimization Modeling for Efficiency Technologies" (COMET) to understand how vehicle manufacturers implement fuel economy technologies to comply with multiple regulations. We consider a variety of scenarios to measure the interaction between regulations and how they may lead to changes in technology costs. In 2025, unit costs reach $1,600 per vehicle on average to comply with CAFE/GHG and increase to $2,000 per vehicle on average to comply with both CAFE/GHG and ZEV. Unit costs for both regulations are less than the sum of the two because vehicles produced to comply with the ZEV program count toward compliance with the CAFE.

Willingness-to-pay for sustainable beer.

Breweries across the country are investing in energy efficient and low-carbon brewing practices. Drawing insights from the sustainable consumption and ecological economics literature, this analysis evaluates whether consumers are willing to pay more for sustainable beer and what predicts the value of the premium. Based on a survey of beer consumers from across the U.S. that contained one of two willingness-to-pay exercises, we evaluate what respondent attributes are associated with a higher willingness-to-pay for sustainably brewed beer. We find that the majority of beer consumers are willing to pay more for sustainable beer. Consumers who are prepared to pay a premium tend to already pay more per unit of beer, are more aware of their purchasing behavior and the manner in which their consumption patterns may affect the environment, and pursue lifestyles based on professional advancement, helping the environment, and helping other causes.

The Role of Public Policy in Technology Diffusion: The Case of Plug-in Electric Vehicles.

The plug-in electric vehicle (PEV) is regarded by many as a viable alternative to the internal combustion engine, so long as the radical technology is able to overcome technical and financial shortcomings that dictate consumer acceptance. States have instituted a variety of policies aimed at mitigating these shortcomings and simultaneously increasing consumer demand for PEV vehicles. Motivated by a limited body of literature on the effects of these policies, and a significant need for information about policy efficacy, in this study we evaluate the relationship between a suite of state-level policies and PEV registrations. Results reveal that tax credits for individuals, grants programs for charging infrastructure and PEV purchases, and incentives for state-owned PEVs fleets increase PEV registrations. The observed impact of grant incentives is mediated by charging capacity or, alternatively phrased, much of the influence of grants on registrations is through the channel of first improving the charging infrastructure within a state.

"Not in (or under) my backyard": Geographic proximity and public acceptance of carbon capture and storage facilities.

Carbon capture and storage (CCS) is an innovative technical approach to mitigate the problem of climate change by capturing carbon dioxide emissions and injecting them underground for permanent geological storage. CCS has been perceived both positively, as an innovative approach to facilitate a more environmentally benign use of fossil fuels while also generating local economic benefits, and negatively, as a technology that prolongs the use of carbon-intensive energy sources and burdens local communities with prohibitive costs and ecological and human health risks. This article extends existing research on the "not in my backyard" (NIMBY) phenomenon in a direction that explores the public acceptance of CCS. We utilize survey data collected from 1,001 residents of the coal-intensive U.S. state of Indiana. Over 80% of respondents express support for the general use of CCS technology. However, 20% of these initial supporters exhibit a NIMBY-like reaction and switch to opposition as a CCS facility is proposed close to their communities. Respondents' worldviews, their beliefs about the local economic benefits that CCS will generate, and their concerns about its safety have the greatest impact on increasing or decreasing the acceptance of nearby facilities. These results lend valuable insights into the perceived risks associated with CCS technology and the possibilities for its public acceptance at both a national and local scale. They may be extended further to provide initial insights into likely public reactions to other technologies that share a similar underground dimension, such as hydraulic fracturing.

Early public impressions of terrestrial carbon capture and storage in a coal-intensive state.

While carbon capture and storage (CCS) is considered to be critical to achieving long-term climate-protection goals, public concerns about the CCS practice could pose significant obstacles to its deployment. This study reports findings from the first state-wide survey of public perceptions of CCS in a coal-intensive state, with an analysis of which factors predict early attitudes toward CCS. Nearly three-quarters of an Indiana sample (N = 1001) agree that storing carbon underground is a good approach to protecting the environment, despite 80% of the sample being unaware of CCS prior to participation in the two-wave survey. The majority of respondents do not hold strong opinions about CCS technology. Multivariate analyses indicate that support for CCS is predicted by a belief that humankind contributes to climate change, a preference for increased use of renewable energy, and egalitarian and individualistic worldviews, while opposition to CCS is predicted by self-identified political conservatism and by selective attitudes regarding energy and climate change. Knowledge about early impressions of CCS can help inform near-term technology decisions at state regulatory agencies, utilities, and pipeline companies, but follow-up surveys are necessary to assess how public sentiments evolve in response to image-building efforts with different positions on coal and CCS.