Cleansing
Positive Spillovers from Infrastructure Investment: How Pipeline Expansions Encourage Fuel Switching
Jonathan Scott
Review of Economics and Statistics, forthcoming
Abstract:
This paper studies the role of the U.S. pipeline infrastructure in the country's transition from coal to natural gas energy. I leverage the EPA's Mercury and Air Toxics Standards as a plausibly exogenous intervention, which encouraged many coal plants to convert to natural gas. Combining this quasi-experimental variation with a plant's preexisting proximity to the pipeline network, I isolate implied pipeline connection costs within a dynamic discrete choice model of plant conversions. Key model results indicate that infrastructure-related costs prevent $9 billion in emissions reductions from taking place, suggesting a $2.4 million per mile external benefit of pipeline expansions.
Changing Susceptibility to Cold Weather in Texas Power Demand
Blake Shaffer, Daniel Quintero & Joshua Rhodes
University of Texas Working Paper, November 2021
Abstract:
We estimate the effect of heightened temperature sensitivity on electricity demand in Texas during the February 2021 blackout event. Using 20 years of hourly data, we estimate the relationship between temperature and electricity demand, finding electricity demand has become more responsive to cold temperatures over time across much of the state. This is consistent with the fact electric heating penetration has similarly increased over the past 20 years in Texas. We use these results to project the effect of increased sensitivity to cold temperatures on electricity demand over the range of temperatures observed during the blackout event. We find total electric load was 8% higher on average, and slightly more than 10,000 megawatts higher during the peak hour, than it would have been had temperature sensitivity remained unchanged at early 2000s levels. Our results highlight that Texas's increased susceptibility to cold weather extremes is not limited to the supply side, but the demand side as well. These findings have implications to other regions in the United States and globally that are seeking to reduce their carbon emissions through the electrification of space heating.
Early life lead exposure from private well water increases juvenile delinquency risk among US teens
Jacqueline MacDonald Gibson et al.
Proceedings of the National Academy of Sciences, 8 February 2022
Abstract:
Early life exposure to environmental lead (Pb) has been linked to decreased IQ, behavior problems, lower lifetime earnings, and increased criminal activity. Beginning in the 1970s, limits on Pb in paint, gasoline, food cans, and regulated water utilities sharply curtailed US environmental Pb exposure. Nonetheless, hundreds of thousands of US children remain at risk. This study reports on how unregulated private well water is an underrecognized Pb exposure source that is associated with an increased risk of teenage juvenile delinquency. We build a longitudinal dataset linking blood Pb measurements for 13,580 children under age 6 to their drinking water source, individual- and neighborhood-level demographics, and reported juvenile delinquency records. We estimate how early life Pb exposure from private well water influences reported delinquency. On average, children in homes with unregulated private wells had 11% higher blood Pb than those with community water service. This higher blood Pb was significantly associated with reported delinquency. Compared to children with community water service, those relying on private wells had a 21% (95% CI: 5 to 40%) higher risk of being reported for any delinquency and a 38% (95% CI: 10 to 73%) increased risk of being reported for serious delinquency after age 14. These results suggest that there could be substantial but as-yet-unrecognized social benefits from intervention programs to prevent children’s exposure to Pb from private wells, on which 13% of the US population relies.
Drinking Water, Fracking, and Infant Health
Elaine Hill & Lala Ma
Journal of Health Economics, forthcoming
Abstract:
This study assesses the health risks associated with drinking water contamination using variation in the timing and location of shale gas development (SGD). Our novel dataset, linking health and drinking water outcomes to shale gas activity through water sources, enables us to provide new estimates of the causal effects of water pollution on health and to isolate drinking water as a specific mechanism of exposure for SGD. We find consistent and robust evidence that drilling shale gas wells negatively impacts both drinking water quality and infant health. These results indicate large social costs of water pollution and provide impetus for re-visiting the regulation of public drinking water.
Are power plant closures a breath of fresh air? Local air quality and school absences
Sarah Komisarow & Emily Pakhtigian
Journal of Environmental Economics and Management, forthcoming
Abstract:
In this paper we study the effects of three large, nearly-simultaneous coal-fired power plant closures on school absences in Chicago. We find that the closures resulted in a 6 percent reduction in absenteeism in nearby schools relative to those farther away following the closures. For the typical elementary school in our sample, this translates into around 363 fewer absence-days per year in the aggregate, or 0.66 fewer annual absences per student. To explore potential mechanisms responsible for these absence reductions we investigate the effects of the closures on endogenous migration to neighborhoods near the plants (mediated through housing prices) and emergency department visits for asthma-related conditions among school-age children. We do not find strong evidence of endogenous migration into neighborhoods near the coal-fired power plants following the closures but do find declines in rates of emergency department visits in areas near the three plants. Given inequalities in exposure to operational coal-fired power plants and other large, industrial polluters, our findings suggest that transitions towards alternative energy sources could play an important role in addressing educational inequality.
The impact of air pollution on birthweight: Evidence from grouped quantile regression
Martina Pons
Empirical Economics, January 2022, Pages 279–296
Abstract:
Estimates of the average effect of pollution on birthweight might not provide a complete picture if more vulnerable infants are disproportionately more affected. To address this, I focus on the distributional effect of particulate matter pollution (PM2.52.5) on birthweight. To estimate the impact, this paper uses grouped quantile regression, a methodology developed by Chetverikov et al. (Econometrica 84(2): 809–833, 2016), which allows estimating the impact of a group-level treatment on an individual-level outcome when there are group-level unobservables. The analysis reveals nonhomogeneous effects indicating that pollution disproportionately affects infants in the lower tail of the conditional distribution, whereas average effects suggest only minimal and not economically significant impact of pollution on birthweight. The findings are also consistent across different specifications.
Exposure to unconventional oil and gas development and all-cause mortality in Medicare beneficiaries
Longxiang Li et al.
Nature Energy, forthcoming
Abstract:
Little is known about whether exposure to unconventional oil and gas development is associated with higher mortality risks in the elderly and whether related air pollutants are exposure pathways. We studied a cohort of 15,198,496 Medicare beneficiaries (136,215,059 person-years) in all major US unconventional exploration regions from 2001 to 2015. We gathered data from records of more than 2.5 million oil and gas wells. For each beneficiary’s ZIP code of residence and year in the cohort, we calculated a proximity-based and a downwind-based pollutant exposure. We analysed the data using two methods: a Cox proportional hazards model and a difference-in-differences design. We found evidence of a statistically significant higher mortality risk associated with living in proximity to and downwind of unconventional oil and gas wells. Our results suggest that primary air pollutants sourced from unconventional oil and gas exploration can be a major exposure pathway with adverse health effects in the elderly.
Association of improved air quality with lower dementia risk in older women
Xinhui Wang et al.
Proceedings of the National Academy of Sciences, 11 January 2022
Abstract:
Late-life ambient air pollution is a risk factor for brain aging, but it remains unknown if improved air quality (AQ) lowers dementia risk. We studied a geographically diverse cohort of older women dementia free at baseline in 2008 to 2012 (n = 2,239, aged 74 to 92). Incident dementia was centrally adjudicated annually. Yearly mean concentrations of fine particulate matter (PM2.5) and nitrogen dioxide (NO2) were estimated using regionalized national universal kriging models and averaged over the 3-y period before baseline (recent exposure) and 10 y earlier (remote exposure). Reduction from remote to recent exposures was used as the indicator of improved AQ. Cox proportional hazard ratios (HRs) for dementia risk associated with AQ measures were estimated, adjusting for sociodemographic, lifestyle, and clinical characteristics. We identified 398 dementia cases during follow up (median = 6.1 y). PM2.5 and NO2 reduced significantly over the 10 y before baseline. Larger AQ improvement was associated with reduced dementia risks (HRPM2.5 0.80 per 1.78 μg/m3, 95% CI 0.71–0.91; HRNO2 0.80 per 3.91 parts per billion, 95% CI 0.71–0.90), equivalent to the lower risk observed in women 2.4 y younger at baseline. Higher PM2.5 at baseline was associated with higher dementia risk (HRPM2.5 1.16 per 2.90 μg/m3, 95% CI 0.98–1.38), but the lower dementia risk associated with improved AQ remained after further adjusting for recent exposure. The observed associations did not substantially differ by age, education, geographic region, Apolipoprotein E e4 genotypes, or cardiovascular risk factors. Long-term AQ improvement in late life was associated with lower dementia risk in older women.
Risk-Taking and Air Pollution: Evidence from Chess
Joris Klingen & Jos van Ommeren
Environmental and Resource Economics, January 2022, Pages 73–93
Abstract:
Medical research suggests that particulate matter (PM) increases stress hormones, therefore increasing the feeling of stress, which has been hypothesised to induce individuals to take less risk. To examine this, we study whether PM10 increases the probability of drawing in chess games using information from the Dutch club competition. We provide evidence of a reasonably strong effect: A 10μg increase in PM10 (33.6% of mean concentration) leads to a 5.6% increase in draws. We examine a range of explanations for these findings. Our preferred interpretation is that air pollution causes individuals to take less risk.
Bioinspired hierarchical porous membrane for efficient uranium extraction from seawater
Linsen Yang et al.
Nature Sustainability, January 2022, Pages 71-80
Abstract:
The oceans offer a virtually infinite source of uranium and could sustain nuclear power technology in terms of fuel supply. However, the current processes to extract uranium from seawater remain neither economically viable nor efficient enough to compete with uranium ore mining. Microporous polymers are emerging materials for the adsorption of uranyl ions due to their rich binding sites, but they still fall short of satisfactory performance. Here, inspired by the ubiquitous fractal structure in biology that is favourable for mass and fluid transfer, we describe a hierarchical porous membrane based on polymers of intrinsic microporosity that can capture uranium in seawater. This biomimetic membrane allows for rapid diffusion of uranium species, leading to a 20-fold higher uranium adsorption capacity in a uranium-spiked water solution (32 ppm) than the membrane with only intrinsic microporosity. Furthermore, in natural seawater, the membrane can extract as much uranium as 9.03 mg g−1 after four weeks. This work suggests a strategy to be extended to the rational design of a large family of microporous polymer adsorbents that could fulfil the vast promise of the oceans to fuel a reliable and potentially sustainable energy source.
Measuring biodiversity from DNA in the air
Elizabeth Clare et al.
Current Biology, 7 February 2022, Pages 693-700
Abstract:
The crisis of declining biodiversity exceeds our current ability to monitor changes in ecosystems. Rapid terrestrial biomonitoring approaches are essential to quantify the causes and consequences of global change. Environmental DNA has revolutionized aquatic ecology, permitting population monitoring and remote diversity assessments matching or outperforming conventional methods of community sampling. Despite this model, similar methods have not been widely adopted in terrestrial ecosystems. Here, we demonstrate that DNA from terrestrial animals can be filtered, amplified, and then sequenced from air samples collected in natural settings representing a powerful tool for terrestrial ecology. We collected air samples at a zoological park, where spatially confined non-native species allowed us to track DNA sources. We show that DNA can be collected from air and used to identify species and their ecological interactions. Air samples contained DNA from 25 species of mammals and birds, including 17 known terrestrial resident zoo species. We also identified food items from air sampled in enclosures and detected taxa native to the local area, including the Eurasian hedgehog, endangered in the United Kingdom. Our data demonstrate that airborne eDNA concentrates around recently inhabited areas but disperses away from sources, suggesting an ecology to airborne eDNA and the potential for sampling at a distance. Our findings demonstrate the profound potential of air as a source of DNA for global terrestrial biomonitoring.
“Late-stage” deforestation enhances storm trends in coastal West Africa
Christopher Taylor et al.
Proceedings of the National Academy of Sciences, 11 January 2022
Abstract:
Deforestation affects local and regional hydroclimate through changes in heating and moistening of the atmosphere. In the tropics, deforestation leads to warming, but its impact on rainfall is more complex, as it depends on spatial scale and synoptic forcing. Most studies have focused on Amazonia, highlighting that forest edges locally enhance convective rainfall, whereas rainfall decreases over drier, more extensive, deforested regions. Here, we examine Southern West Africa (SWA), an example of “late-stage” deforestation, ongoing since 1900 within a 300-km coastal belt. From three decades of satellite data, we demonstrate that the upward trend in convective activity is strongly modulated by deforestation patterns. The frequency of afternoon storms is enhanced over and downstream of deforested patches on length scales from 16 to 196 km, with greater increases for larger patches. The results are consistent with the triggering of storms by mesoscale circulations due to landscape heterogeneity. Near the coast, where sea breeze convection dominates the diurnal cycle, storm frequency has doubled in deforested areas, attributable to enhanced land–sea thermal contrast. These areas include fast-growing cities such as Freetown and Monrovia, where enhanced storm frequency coincides with high vulnerability to flash flooding. The proximity of the ocean likely explains why ongoing deforestation across SWA continues to increase storminess, as it favors the impact of mesoscale dynamics over moisture availability. The coastal location of deforestation in SWA is typical of many tropical deforestation hotspots, and the processes highlighted here are likely to be of wider global relevance.