Going with the flow
Weather conditions conducive to Beijing severe haze more frequent under climate change
Wenju Cai et al.
Nature Climate Change, April 2017, Pages 257–262
Abstract:
The frequency of Beijing winter severe haze episodes has increased substantially over the past decades, and is commonly attributed to increased pollutant emissions from China’s rapid economic development. During such episodes, levels of fine particulate matter are harmful to human health and the environment, and cause massive disruption to economic activities, as occurred in January 2013. Conducive weather conditions are an important ingredient of severe haze episodes, and include reduced surface winter northerlies, weakened northwesterlies in the midtroposphere, and enhanced thermal stability of the lower atmosphere. How such weather conditions may respond to climate change is not clear. Here we project a 50% increase in the frequency and an 80% increase in the persistence of conducive weather conditions similar to those in January 2013, in response to climate change. The frequency and persistence between the historical (1950–1999) and future (2050–2099) climate were compared in 15 models under Representative Concentration Pathway 8.5 (RCP8.5). The increased frequency is consistent with large-scale circulation changes, including an Arctic Oscillation upward trend, weakening East Asian winter monsoon, and faster warming in the lower troposphere. Thus, circulation changes induced by global greenhouse gas emissions can contribute to the increased Beijing severe haze frequency.
“Green to be seen” and “brown to keep down”: Visibility moderates the effect of identity on pro-environmental behavior
Cameron Brick, David Sherman & Heejung Kim
Journal of Environmental Psychology, August 2017, Pages 226–238
Abstract:
Social identities predict pro-environmental behavior, but the strength may depend on whether the behavior is visible to others. When an environmentalist considers a pro-environmental behavior such as carrying reusable grocery bags, being observed by others may motivate signaling the valued group membership and may increase behavior (“green to be seen”). When an anti-environmentalist considers a pro-environmental behavior that could signal that unwanted social identity, being observed may lead to less behavior (“brown to keep down”). United States residents completed three correlational surveys (total N = 1126) of identity, visibility, and self-reported behavior frequency using the Recurring Pro-environmental Behavior Scale. Three multilevel studies revealed that environmentalist identity predicted pro-environmental behavior more stronger for high-visibility behaviors, controlling for confounds at the person level (attitudes, political identity) and the behavior level (difficulty, effectiveness). This research helps uncover the key social identities and contextual factors that lead individuals to embrace or reject pro-environmental behaviors.
Bridging the political divide: Highlighting explanatory power mitigates biased evaluation of climate arguments
Dan Johnson
Journal of Environmental Psychology, August 2017, Pages 248–255
Abstract:
Climate change beliefs' strong ties to political ideology remains one of the most significant impediments to productive public discourse about climate change. Ideologically-driven motivated reasoning leads to biased evaluation of climate change arguments. The current studies offer a novel cognitive approach to mitigate biased evaluation. Republicans and Democrats were randomly assigned to either focus carefully on an argument's quality or focus on how well an argument explained how the main point leads to the proposed outcome – termed, mechanistic explanatory power. Focusing on the mechanistic explanatory power of anti-climate change scientific explanations (Study 1) and pro-environmental behavior arguments (Study 2) substantially reduced biased evaluation and bridged the political ideological divide. These results have practical implications for policy makers and climate change communicators: 1) climate change material should contain mechanistic explanation, and 2) one should highlight the presence or absence of mechanistic explanatory power in an argument.
Wealth Inequality and Carbon Emissions in High-income Countries
Kyle Knight, Juliet Schor & Andrew Jorgenson
Social Currents, forthcoming
Abstract:
This study contributes to the emerging literature on connections between climate change and economic inequality by investigating the relationship between domestic wealth inequality and consumption-based carbon emissions for 26 high-income countries from 2000 to 2010. Results of the two-way fixed effects longitudinal models indicate that the effect of wealth inequality, measured as the wealth share of the top decile, on per capita emissions in high-income countries is consistently positive and relatively stable over the time period. This finding is consistent with political economy theories arguing that the concentration of political and economic power that accompanies the concentration of wealth plays an important role in increasing environmental degradation and preventing proenvironmental actions.
Is it hot in here or is it just me? Temperature anomalies and political polarization over global warming in the American public
Jeremiah Bohr
Climatic Change, May 2017, Pages 271–285
Abstract:
Do temperature anomalies affect political polarization over global warming? Americans’ attitudes about global warming are affected by whether they reside in states experiencing unseasonably warm (or cold) temperatures versus those experiencing milder temperatures. Specifically, in terms of causal attribution, political polarization over global warming is more pronounced in states experiencing temperature anomalies. Using pooled data collected during 2013–2014, this study utilizes logistic regression to explore how temperature anomalies exacerbate the political polarization among Americans over perceptions of whether global warming impacts are immediately evident as well as the attribution of global warming to human activity. Results indicate that very cold or warm temperature anomalies from a 5-year baseline predict perceptions of global warming impacts and exacerbate existing political polarization over the causal attribution of global warming. These effects are particularly noticeable among Democrats. This analysis provides a contribution to understanding how temperature anomalies from the recent past shape the sociophysical context of global warming attitudes.
The Effect of Fuel Economy Standards on Vehicle Weight Dispersion and Accident Fatalities
Antonio Bento, Kenneth Gillingham & Kevin Roth
NBER Working Paper, April 2017
Abstract:
The firm response to regulation is seldom as controversial as in the context of fuel economy standards, a dominant policy to reduce emissions from vehicles worldwide. It has long been argued that such standards lead to vehicle weight changes that increase accident fatalities. Using unconditional quantile regression, we are the first to document the effect of the Corporate Average Fuel Economy (CAFE) standards on the vehicle weight distribution. We find that on net CAFE reduced fatalities, with lowered mean weight dominating increased dispersion. When monetized, this effect suggests positive net benefits from CAFE even with no undervaluation of fuel economy.
Safer or Cheaper? Traffic Safety, Vehicle Choices and the Effect of New Corporate Average Fuel Economy Standards
Yizao Liu
Resource and Energy Economics, forthcoming
Abstract:
The new Corporate Average Fuel Economy (CAFE) Standards increase fuel economy to 54.5 MPG by model year 2025 and determine fuel economy targets based on vehicle sizes. This paper examines the effect of the new CAFE standards on consumer choices and composition of vehicle sales, accounting for the impact of traffic safety. We first formulate and estimate a mixed logit model of consumer demand using micro-level data. Two measures of traffic safety, consumers’ safety concerns and traffic fatalities, are included and interacted with two vehicle characteristics that matter most for traffic safety: weight and size. Further, we conduct simulations of three extreme firm responses to assess the potential impact of the new CAFE standards: lightweighting, paying CAFE fines, and size increase. Simulation results suggest that the sales impact will fall almost entirely on the SUV and light truck segments and on US automakers that use lightweighting. Moreover, consumers in states with more traffic fatalities are the most responsive, shifting away from passenger cars. In addition, the new CAFE standards could result in an increase of 8.1 percent in the share of SUV and light trucks, which will cause as many as 347 more equivalent fatalities on roads each year.
Measuring the Welfare Effects of Residential Energy Efficiency Programs
Hunt Allcott & Michael Greenstone
University of Chicago Working Paper, April 2017
Abstract:
This paper sets out a framework to evaluate the welfare impacts of residential energy efficiency programs in the presence of imperfect information, behavioral biases, and externalities, then estimates key parameters using a 100,000-household field experiment. Several results run counter to conventional wisdom: we find no evidence of informational or behavioral failures thought to reduce program participation, there are large unobserved benefits and costs that traditional evaluations miss, and realized energy savings are only 58 percent of predictions. In the context of the model, the two programs we study reduce social welfare by $0.18 per subsidy dollar spent, both because subsidies are not well-calibrated to currently-estimated externality damages and because of self-selection induced by subsidies that attract households whose participation generates low social value. However, the model predicts that perfectly-calibrated subsidies would increase welfare by $2.53 per subsidy dollar, revealing the potential of energy efficiency programs.
Projected Increases in Hurricane Damage in the United States: The Role of Climate Change and Coastal Development
Terry Dinan
Ecological Economics, August 2017, Pages 186–198
Abstract:
The combined forces of climate change and coastal development are anticipated to increase hurricane damage around the globe. Estimating the magnitude of those increases is challenging due to substantial uncertainties about the amount by which climate change will alter the formation of hurricanes and increase sea levels in various locations; and the fact that future increases in property exposure are uncertain, reflecting local, regional and national trends as well as unforeseen circumstances. This paper assesses the potential increase in wind and storm surge damage caused by hurricanes making landfall in the U.S. between now and 2075 using a framework that addresses those challenges. We find that, in combination, climate change and coastal development will cause hurricane damage to increase faster than the U.S. economy is expected to grow. In addition, we find that the number of people facing substantial expected damage will, on average, increase more than eight-fold over the next 60 years. Understanding the concentration of damage may be particularly important in countries that lack policies or programs to provide federal support to hard-hit localities.
Migration induced by sea-level rise could reshape the US population landscape
Mathew Hauer
Nature Climate Change, May 2017, Pages 321–325
Abstract:
Many sea-level rise (SLR) assessments focus on populations presently inhabiting vulnerable coastal communities, but to date no studies have attempted to model the destinations of these potentially displaced persons. With millions of potential future migrants in heavily populated coastal communities, SLR scholarship focusing solely on coastal communities characterizes SLR as primarily a coastal issue, obscuring the potential impacts in landlocked communities created by SLR-induced displacement. Here I address this issue by merging projected populations at risk of SLR with migration systems simulations to project future destinations of SLR migrants in the United States. I find that unmitigated SLR is expected to reshape the US population distribution, potentially stressing landlocked areas unprepared to accommodate this wave of coastal migrants — even after accounting for potential adaptation. These results provide the first glimpse of how climate change will reshape future population distributions and establish a new foundation for modelling potential migration destinations from climate stressors in an era of global environmental change.
The Impact of Prenatal Exposure to Power Plant Emissions on Birth Weight: Evidence from a Pennsylvania Power Plant Located Upwind of New Jersey
Muzhe Yang et al.
Journal of Policy Analysis and Management, forthcoming
Abstract:
To examine the infant health impact of prenatal exposure to power plant emissions, we draw scientific evidence on the impacted region downwind of a large polluter, a coal-fired power plant located on the border of two states and proven to be the sole contributor to the violation of air quality standards of the impacted region. Our results show that among all live singleton births that occurred during 1990 through 2006, those born to mothers living as far as 20 to 30 miles away downwind from the power plant (which is also an affluent region) during pregnancy are at greater risks of low birth weight (LBW) and very low birth weight (VLBW): the likelihoods of LBW and VLBW could increase approximately by 6.50 and 17.12 percent, respectively. In light of the continual efforts of The U.S. Environmental Protection Agency in reducing cross-state air pollution caused by transboundary power plant emissions, our study is aimed at broadening the scope of cross-border pollution impact analysis by taking into account adverse infant health effects of upwind polluters, which can impose disproportionate burdens of health risks on downwind states due to air pollutants transported by wind.
Happiness in the Air: How Does a Dirty Sky Affect Mental Health and Subjective Well-being
Xin Zhang, Xiaobo Zhang & Xi Chen
Journal of Environmental Economics and Management, forthcoming
Abstract:
Previous studies evaluating the welfare cost of air pollution have not paid much attention to its potential effect on mental health and subjective well-being (SWB). This paper attempts to fill the gap by investigating the impact of air pollution on several key dimensions, including mental health status, depressive symptoms, moment-to-moment happiness, and evaluative happiness. We match a nationwide longitudinal survey in China with local air quality and rich weather conditions according to the exact time and place of survey. By making use of variations in exposure to air pollution for the same individuals over time, we show that air pollution reduces hedonic happiness and increases the rate of depressive symptoms, while life satisfaction has little to do with the immediate air quality. Our results shed light on air pollution as an important contributor to the Easterlin paradox that economic growth may not bring more happiness.
The role of CO2 capture and utilization in mitigating climate change
Niall Mac Dowell et al.
Nature Climate Change, April 2017, Pages 243–249
Abstract:
To offset the cost associated with CO2 capture and storage (CCS), there is growing interest in finding commercially viable end-use opportunities for the captured CO2. In this Perspective, we discuss the potential contribution of carbon capture and utilization (CCU). Owing to the scale and rate of CO2 production compared to that of utilization allowing long-term sequestration, it is highly improbable the chemical conversion of CO2 will account for more than 1% of the mitigation challenge, and even a scaled-up enhanced oil recovery (EOR)-CCS industry will likely only account for 4–8%. Therefore, whilst CO2-EOR may be an important economic incentive for some early CCS projects, CCU may prove to be a costly distraction, financially and politically, from the real task of mitigation.
More connected urban roads reduce US GHG emissions
Chris Barrington-Leigh & Adam Millard-Ball
Environmental Research Letters, April 2017
Abstract:
We quantify the importance of early action to tackle urban sprawl. We focus on the long-term nature of infrastructure decisions, specifically local roadways, which can lock in greenhouse gas emissions for decades to come. The location and interconnectedness of local roadways form a near-permanent backbone for the future layout of land parcels, buildings, and transportation options. We provide new estimates of the environmental impact of low-connectivity roads, characterized by cul-de-sacs and T-intersections, which we dub street-network sprawl. We find an elasticity of vehicle ownership with respect to street connectivity of –0.15 — larger than suggested by previous research. We then apply this estimate to quantify the long-term emissions implications of alternative scenarios for street-network sprawl. On current trends alone, we project vehicle travel and emissions to fall by ~3.2% over the 2015–2050 period, compared to a scenario where sprawl plateaus at its 1994 peak. Concerted policy efforts to increase street connectivity could more than triple these reductions to ~8.8% by 2050. Longer-term reductions over the 2050–2100 period are more speculative, but could be more than 50% greater than those achieved by 2050. The longer the timescale over which mitigation efforts are considered, the more important it becomes to address the physical form of the built environment.
Ocean warming since 1982 has expanded the niche of toxic algal blooms in the North Atlantic and North Pacific oceans
Christopher Gobler et al.
Proceedings of the National Academy of Sciences, forthcoming
Abstract:
Global ocean temperatures are rising, yet the impacts of such changes on harmful algal blooms (HABs) are not fully understood. Here we used high-resolution sea-surface temperature records (1982 to 2016) and temperature-dependent growth rates of two algae that produce potent biotoxins, Alexandrium fundyense and Dinophysis acuminata, to evaluate recent changes in these HABs. For both species, potential mean annual growth rates and duration of bloom seasons significantly increased within many coastal Atlantic regions between 40°N and 60°N, where incidents of these HABs have emerged and expanded in recent decades. Widespread trends were less evident across the North Pacific, although regions were identified across the Salish Sea and along the Alaskan coastline where blooms have recently emerged, and there have been significant increases in the potential growth rates and duration of these HAB events. We conclude that increasing ocean temperature is an important factor facilitating the intensification of these, and likely other, HABs and thus contributes to an expanding human health threat.
The contribution of solar brightening to the US maize yield trend
Matthijs Tollenaar et al.
Nature Climate Change, April 2017, Pages 275–278
Abstract:
Predictions of crop yield under future climate change are predicated on historical yield trends, hence it is important to identify the contributors to historical yield gains and their potential for continued increase. The large gains in maize yield in the US Corn Belt have been attributed to agricultural technologies, ignoring the potential contribution of solar brightening (decadal-scale increases in incident solar radiation) reported for much of the globe since the mid-1980s. In this study, using a novel biophysical/empirical approach, we show that solar brightening contributed approximately 27% of the US Corn Belt yield trend from 1984 to 2013. Accumulated solar brightening during the post-flowering phase of development of maize increased during the past three decades, causing the yield increase that previously had been attributed to agricultural technology. Several factors are believed to cause solar brightening, but their relative importance and future outlook are unknown, making prediction of continued solar brightening and its future contribution to yield gain uncertain. Consequently, results of this study call into question the implicit use of historical yield trends in predicting yields under future climate change scenarios.
The economic value of grassland species for carbon storage
Bruce Hungate et al.
Science Advances, April 2017
Abstract:
Carbon storage by ecosystems is valuable for climate protection. Biodiversity conservation may help increase carbon storage, but the value of this influence has been difficult to assess. We use plant, soil, and ecosystem carbon storage data from two grassland biodiversity experiments to show that greater species richness increases economic value: Increasing species richness from 1 to 10 had twice the economic value of increasing species richness from 1 to 2. The marginal value of each additional species declined as species accumulated, reflecting the nonlinear relationship between species richness and plant biomass production. Our demonstration of the economic value of biodiversity for enhancing carbon storage provides a foundation for assessing the value of biodiversity for decisions about land management. Combining carbon storage with other ecosystem services affected by biodiversity may well enhance the economic arguments for conservation even further.
Climate change enhances interannual variability of the Nile river flow
Mohamed Siam & Elfatih Eltahir
Nature Climate Change, May 2017, Pages 350–354
Abstract:
The human population living in the Nile basin countries is projected to double by 2050, approaching one billion. The increase in water demand associated with this burgeoning population will put significant stress on the available water resources. Potential changes in the flow of the Nile River as a result of climate change may further strain this critical situation. Here, we present empirical evidence from observations and consistent projections from climate model simulations suggesting that the standard deviation describing interannual variability of total Nile flow could increase by 50% (±35%) (multi-model ensemble mean ± 1 standard deviation) in the twenty-first century compared to the twentieth century. We attribute the relatively large change in interannual variability of the Nile flow to projected increases in future occurrences of El Niño and La Niña events and to observed teleconnection between the El Niño–Southern Oscillation and Nile River flow. Adequacy of current water storage capacity and plans for additional storage capacity in the basin will need to be re-evaluated given the projected enhancement of interannual variability in the future flow of the Nile river.