Looking for Green
The Climate Adaptation Feedback
Alexander Abajian et al.
NBER Working Paper, February 2025
Abstract:
Many behavioral responses to climate change are carbon-intensive, raising concerns that adaptation may cause additional warming. The sign and magnitude of this
feedback depend on how increased emissions from cooling balance against reduced emissions from heating across space and time. We present an empirical approach that forecasts the effect of future adaptive energy use on global average temperature over the 21st century. We find energy-based adaptation will lower global mean surface temperature in 2099 by 0.12 degrees Celsius (0.07 degrees Celsius) relative to baseline projections under RCP8.5 (RCP4.5) and avoid 1.8 (0.6) trillion USD ($2019) in damages. Energy-based adaptation lowers business-as-usual emissions for 85% of countries, reducing the mitigation required to meet their unilateral Nationally Determined Contributions under the UNFCCC by 20% on average. These findings indicate that while business-as-usual adaptive energy use is unlikely to accelerate warming, it raises important implications for countries’ existing mitigation commitments.
Environmental regulation, regulatory spillovers and rent-seeking
Juan Pablo González
Public Choice, January 2025, Pages 217–250
Abstract:
How do special interests react to an increase in their regulatory burden? In this paper, I use a shock to the regulatory environment by analyzing state-level enforcement of the Clean Air Act during the fracking boom. First, I show that fracking is associated with an increase in state regulatory activities for non-energy-related industries, generating regulatory spillovers to firms unrelated to fracking. Using the fact that fracking had regulatory spillovers to other industries, I use the presence of fracking as an instrument for environmental regulation for non-energy-related firms. I find that increased environmental enforcement is associated with an increase in state campaign contributions going to Republicans, and particularly to legislative races in competitive districts. These results provide some of the first evidence that changes in the regulatory environment can spur private sector mobilization with the potential to affect broader areas of policy through its electoral consequences.
Populations of large-diameter trees are increasing across the United States
Paul Chisholm & Andrew Gray
Proceedings of the National Academy of Sciences, 18 March 2025
Abstract:
Large-diameter trees provide vital ecological functions in forested ecosystems. Old, large-diameter trees may also be vulnerable to climate-driven mortality events, but past work on large tree populations has been geographically limited. Here, we characterize the population of large-diameter trees from two size categories, 50 to 100 cm diameter at breast height (DBH) (medium) and >100 cm DBH (big), within the United States using Forest Inventory and Analysis data. Although populations of big trees are concentrated along the west coast, populations of medium trees are more evenly distributed across the nation. In the western United States, trees >50 cm DBH comprise ~75% of the total carbon stored in live trees, while in the eastern United States they comprise ~20%. Plot remeasurement data indicate that populations of big trees are increasing at an annual rate of 0.49% in the west and 2.9% in the east, and populations of medium trees are increasing at an annual rate of 0.5% in the west and 2.4% in the east. One exception is the Sierra Nevada region, where big trees are declining. Additionally, we observed declines for several individual species. While the overall population trend for large-diameter trees is positive, declines in these species could have localized impacts for the environments in which they occur.
Does Paying to Pollute Make Pollution Seem Less Bad?
Hajin Kim
University of Chicago Working Paper, October 2024
Abstract:
A common critique of market-based instruments is that they commodify pollution and so reduce its moral stigma. If true, the increasing use of market-based instruments could reduce concern for the environment. With a preregistered and demographically representative experimental vignette study of over 2000 Americans, this project finds evidence against the anti-commodification critique. Participants randomly assigned to learn about market-based regulations of a fictitious new pollutant, malzene, did not find malzene pollution to be less morally problematic than those randomly assigned to learn about a mandate dictating pollution limits. The results were sufficiently precise to rule out any decrease in moral stigma from a pollution tax (as compared to a mandate), and to rule out a decrease larger than 4% from a cap-and-trade program. Market-based regulations can also make pollution look worse: Companies paying to pollute in compliance with market-based instruments looked morally worse than companies polluting in compliance with a mandate. This finding suggests a new and different argument against market-based regulations-that they reduce the reputational benefits of legal compliance. But market-based instruments do not appear to reduce the moral stigma of pollution.
The Effects of Daily Air Pollution on Students and Teachers
Sarah Chung, Claudia Persico & Jing Liu
NBER Working Paper, March 2025
Abstract:
Recent empirical research shows that air pollution harms student test scores and attendance and increases office discipline referrals. However, the mechanism by which air pollution operates within schools to negatively affect student and teacher outcomes remains largely opaque. The existing literature has primarily focused on the effects of prolonged exposure to pollution on end-of-year test scores or total absence counts. We examine how ambient air pollution influences student-by-day and teacher-by-day outcomes, including absences and office discipline referrals, using daily administrative data from a large urban school district in California between 2003 and 2020. Using wind direction as an instrument for daily pollution exposure, we find that a 10 μg/m3 increase in daily PM2.5 causes a 5.7% increase in full-day student absences and a 28% increase in office referrals in a three-day window. Importantly, the effects are driven by low-income, Black, Hispanic, and younger students. In addition, over three days, a 10 μg/m3 increase in daily PM2.5 causes a 13.1% increase in teacher absences due to illness. Our research indicates that decreasing air pollution in urban areas could enhance both student and teacher attendance, and minimize disruptive behavior in educational settings.
Polyethylene packaging and alternative materials in the United States: A life cycle assessment
Elizabeth Avery et al.
Science of The Total Environment, 20 January 2025
Abstract:
A comprehensive life cycle assessment was conducted to evaluate the potential environmental impacts of polyethylene (PE) packaging and its alternatives, including paper, glass, aluminum, and steel in the United States. The assessment focuses on five major packaging applications: collation shrink films, stretch films for pallet wraps, heavy-duty sacks, non-food bottles, and flexible food pouches. The study compares PE and the alternative packaging materials based on the following environmental impact categories: global warming potential (GWP), fossil energy use, mineral resource use, and water scarcity. The research integrates sales volume estimates for each application, examining the substitution ratios of PE-based materials and the GWP decrease capabilities of using PE as packaging material. The findings reveal that substituting PE for other packaging materials can lead to an average life cycle GWP emissions decrease of approximately 70%. This significant decrease highlights the potential GWP benefits of PE in the context of packaging solutions in the United States. We also provide a detailed analysis of the potential environmental impacts and trade-offs associated with PE and its alternatives. The insights gained from this study are intended to assist stakeholders and policymakers in making informed decisions that balance environmental impact mitigation with maintaining product functionality and achieving sustainability objectives.
Continued Atlantic overturning circulation even under climate extremes
Jonathan Baker et al.
Nature, 27 February 2025, Pages 987-994
Abstract:
The Atlantic Meridional Overturning Circulation (AMOC), vital for northwards heat transport in the Atlantic Ocean, is projected to weaken owing to global warming, with significant global climate impacts. However, the extent of AMOC weakening is uncertain with wide variation across climate models and some statistical indicators suggesting an imminent collapse. Here we show that the AMOC is resilient to extreme greenhouse gas and North Atlantic freshwater forcings across 34 climate models. Upwelling in the Southern Ocean, driven by persistent Southern Ocean winds, sustains a weakened AMOC in all cases, preventing its complete collapse. As Southern Ocean upwelling must be balanced by downwelling in the Atlantic or Pacific, the AMOC can only collapse if a compensating Pacific Meridional Overturning Circulation (PMOC) develops. Remarkably, a PMOC does emerge in almost all models, but it is too weak to balance all of the Southern Ocean upwelling, suggesting that an AMOC collapse is unlikely this century. Our findings reveal AMOC-stabilizing mechanisms with implications for past and future AMOC changes, and hence for ecosystems and ocean biogeochemistry. They suggest that better understanding and estimates of the Southern Ocean and Indo-Pacific circulations are urgently needed to accurately predict future AMOC change.
Industrial-scale sustainable rare earth mining enabled by electrokinetics
Gaofeng Wang et al.
Nature Sustainability, February 2025, Pages 182-189
Abstract:
Owing to their irreplaceable role in several essential technologies, rare earth elements (REEs) are critical raw materials for the global economy. However, the supply of REEs raises serious sustainability concerns due to the large environmental footprint of conventional mining processes. We previously proposed an electrokinetic mining (EKM) technique that could enable green and selective extraction of REEs from ores. Here we further develop this technique to industrial scale by addressing challenges related to electrode reliability and flow leakage and evaluate its mining efficiency, environmental footprint and economic performance. Moreover, a voltage gradient barrier strategy based on electroosmosis is developed to facilitate electrokinetic REEs mining. As a result, we successfully achieved a high REE recovery efficiency of 95% on a 5,000-ton REEs ore. A rigorous environmental risk assessment revealed a 95% reduction of ammonia emissions, indicating a notably reduced environmental footprint. A comparative technoeconomic analysis between the conventional and the EKM techniques demonstrates the economic viability of the EKM technique. This work validates a new sustainable path for REEs mining, paving the way to a greener resources supply.
Hunting and Fishing CEOs: Environmental Plunderers or Saviors?
Thomas Covington, Steve Swidler & Keven Yost
Journal of Business Ethics, March 2025, Pages 423-444
Abstract:
CEOs who participate in hunting and fishing benefit by appreciating natural environments and permanently consuming natural resources. We examine whether CEOs who hunt and fish make different environmental decisions and find that firms led by CEOs who obtain the most hunting and fishing licenses have lower environmental performance as measured by MSCI-KLD. This effect is strongest in the environmental category of climate change but also extends to pollution, waste, and the protection of natural capital. Furthermore, firms led by CEOs with the most hunting and fishing licenses are significantly more likely to pay a regulatory settlement for an environmental regulatory infraction.
Hear Ye, Bear Ye: Housing Values, Noise Levels, and Noise Inequality
Jeffrey Cohen, Cletus C. Coughlin & Felix Friedt
University of Connecticut Working Paper, December 2024
Abstract:
We explore how a 2017 federal government policy announcement and 2019 implementation requiring quieter engines in some new commercial aircraft impacted the relationships between home values, transportation noise, and demographics. We focus on aircraft noise in Census tracts across the contiguous U.S., as well as separating road and aircraft noise. Using a panel of tract-level noise data for three years (2016, 2018, and 2020), along with Census data on demographics, house prices, and property characteristics, we first demonstrate numerically and graphically the extent to which some residents experience disproportionate amounts of noise by constructing measures of inequality. Next, we rely on the policy announcement to test the hypothesis that this requirement is a cause of structural change in how aircraft noise affected house prices across demographic groups. We find Census tracts with greater Black population after the announcement and implementation have higher average house values. Also, Census tracts with at least 45 dBA of noise, the federally designated cutoff for annoyance, show higher house values after the announcement and implementation.