Steamy
Civil conflicts are associated with the global climate
Solomon Hsiang, Kyle Meng & Mark Cane
Nature, 25 August 2011, Pages 438-441
Abstract:
It has been proposed that changes in global climate have been responsible for episodes of widespread violence and even the collapse of civilizations. Yet previous studies have not shown that violence can be attributed to the global climate, only that random weather events might be correlated with conflict in some cases. Here we directly associate planetary-scale climate changes with global patterns of civil conflict by examining the dominant interannual mode of the modern climate, the El Niño/Southern Oscillation (ENSO). Historians have argued that ENSO may have driven global patterns of civil conflict in the distant past, a hypothesis that we extend to the modern era and test quantitatively. Using data from 1950 to 2004, we show that the probability of new civil conflicts arising throughout the tropics doubles during El Niño years relative to La Niña years. This result, which indicates that ENSO may have had a role in 21% of all civil conflicts since 1950, is the first demonstration that the stability of modern societies relates strongly to the global climate.
----------------------
Deregulation, Consolidation, and Efficiency: Evidence from U.S. Nuclear Power
Lucas Davis & Catherine Wolfram
NBER Working Paper, August 2011
Abstract:
For the first four decades of its existence the U.S. nuclear power industry was run by regulated utilities, with most companies owning only one or two reactors. Beginning in the late 1990s electricity markets in many states were deregulated and almost half of the nation's 103 reactors were sold to independent power producers selling power in competitive wholesale markets. Deregulation has been accompanied by substantial market consolidation and today the three largest companies control more than one-third of all U.S. nuclear capacity. We find that deregulation and consolidation are associated with a 10 percent increase in operating efficiency, achieved primarily by reducing the frequency and duration of reactor outages. At average wholesale prices the value of this increased efficiency is approximately $2.5 billion annually and implies an annual decrease of almost 40 million metric tons of carbon dioxide emissions.
----------------------
Would you rather be injured by lightning or a downed power line? Preference for natural hazards
Jeffrey Rudski et al.
Judgment and Decision Making, June 2011, Pages 314-322
Abstract:
Past research has shown that many people prefer natural foods and medicines over artificial counterparts. The present study focused on examination of aversive events and hazards. Preferences were compared by having subjects consider pairs of scenarios, one natural and one artificial, matched in negative outcome and severity. Pairings were also rated along several dimensions of risk perception such as dangerousness, scariness, likelihood, and fairness. As hypothesized, natural hazards were consistently preferred to functionally identical artificial ones. Additionally, natural hazards tended to be considered less scary and dangerous, but not necessarily more unfair or unlikely than equivalent artificial counterparts. Results are discussed in terms of risk perception, and how that can lead to people diminishing risks associated with natural hazards.
----------------------
Underestimating Nearby Nature: Affective Forecasting Errors Obscure the Happy Path to Sustainability
Elizabeth Nisbet & John Zelenski
Psychological Science, forthcoming
Abstract:
Modern lifestyles disconnect people from nature, and this may have adverse consequences for the well-being of both humans and the environment. In two experiments, we found that although outdoor walks in nearby nature made participants much happier than indoor walks did, participants made affective forecasting errors, such that they systematically underestimated nature's hedonic benefit. The pleasant moods experienced on outdoor nature walks facilitated a subjective sense of connection with nature, a construct strongly linked with concern for the environment and environmentally sustainable behavior. To the extent that affective forecasts determine choices, our findings suggest that people fail to maximize their time in nearby nature and thus miss opportunities to increase their happiness and relatedness to nature. Our findings suggest a happy path to sustainability, whereby contact with nature fosters individual happiness and environmentally responsible behavior.
----------------------
Environmental Accounting for Pollution in the United States Economy
Nicholas Muller, Robert Mendelsohn & William Nordhaus
American Economic Review, August 2011, Pages 1649-1675
Abstract:
This study presents a framework to include environmental externalities into a system of national accounts. The paper estimates the air pollution damages for each industry in the United States. An integrated-assessment model quantifies the marginal damages of air pollution emissions for the US which are multiplied times the quantity of emissions by industry to compute gross damages. Solid waste combustion, sewage treatment, stone quarrying, marinas, and oil and coal-fired power plants have air pollution damages larger than their value added. The largest industrial contributor to external costs is coal-fired electric generation, whose damages range from 0.8 to 5.6 times value added.
----------------------
Does It Pay to Pollute? Shareholder Wealth Consequences of Corporate Environmental Lawsuits
Zuobao Wei, Feixue Xie & Richard Posthuma
International Review of Law and Economics, forthcoming
Abstract:
In this paper, we employ the event study methodology to examine shareholder wealth consequences of corporate environmental lawsuits filed in the U.S. Circuit Courts from 1980-2001. We find that stocks of defendant firms experience significant negative abnormal returns around the lawsuit filing dates. When the plaintiffs are government entities, the abnormal returns of the defendant stocks are significantly negative. On the other hand, when the plaintiffs are individuals or nonpublic business entities, the abnormal returns are statistically insignificant. When lawsuits are filed under EPA's superfund statute, defendant firms experience significant loss in equity value. For shareholders of the average firm in our sample, the empirical evidence suggests that it does not pay to pollute if the firm is sued.
----------------------
The Effect of Pollution on Labor Supply: Evidence from a Natural Experiment in Mexico City
Rema Hanna & Paulina Oliva
NBER Working Paper, August 2011
Abstract:
Moderate effects of pollution on health may exert an important influence on labor market decisions. We exploit exogenous variation in pollution due to the closure of a large refinery in Mexico City to understand how pollution impacts labor supply. The closure led to an 8 percent decline in pollution in the surrounding neighborhoods. We find that a one percent increase in sulfur dioxide results in a 0.61 percent decrease in the hours worked. The effects do not appear to be driven by labor demand shocks nor differential migration as a result of the closure in the areas located near the refinery.
----------------------
Michael Notaro et al.
International Journal of Climatology, September 2011, Pages 1615-1633
Abstract:
Output from the Climate Model Intercomparison Project Phase 3 (CMIP3) global climate models are statistically downscaled across Wisconsin, using a method that restores the observed mean, variance, and extremes of daily temperature and precipitation. The downscaled climate data for the late 20th century, mid-21st century, and late 21st-century is used to drive the National Weather Service operational snow model, SNOW-17, to produce high-resolution (0.1° × 0.1°) projections of daily snowfall, snow depth, and snow cover for Wisconsin. These snow projections will guide wildlife scientists in climate change impact studies and the development of adaptation strategies for the state, in addition to being of value to hydrologists, agricultural scientists, and other experts. SNOW-17 simulations suggest a dramatic shortening of the Wisconsin snow season, with the greatest snowfall and snow depth reductions in spring, particularly over northern Wisconsin. Snowfall is substantially reduced in response to projected warming and only slightly offset by a projected increase in cold-season precipitation. Percent reductions in snow depth are likely to be even more impressive than in snowfall, given not only a reduced frequency that falling precipitation will be in frozen form but also an enhanced snowmelt due to rising temperatures.
----------------------
Rapid Range Shifts of Species Associated with High Levels of Climate Warming
I-Ching Chen et al.
Science, 19 August 2011, Pages 1024-1026
Abstract:
The distributions of many terrestrial organisms are currently shifting in latitude or elevation in response to changing climate. Using a meta-analysis, we estimated that the distributions of species have recently shifted to higher elevations at a median rate of 11.0 meters per decade, and to higher latitudes at a median rate of 16.9 kilometers per decade. These rates are approximately two and three times faster than previously reported. The distances moved by species are greatest in studies showing the highest levels of warming, with average latitudinal shifts being generally sufficient to track temperature changes. However, individual species vary greatly in their rates of change, suggesting that the range shift of each species depends on multiple internal species traits and external drivers of change. Rapid average shifts derive from a wide diversity of responses by individual species.
----------------------
Permafrost carbon-climate feedbacks accelerate global warming
Charles Koven et al.
Proceedings of the National Academy of Sciences, forthcoming
Abstract:
Permafrost soils contain enormous amounts of organic carbon, which could act as a positive feedback to global climate change due to enhanced respiration rates with warming. We have used a terrestrial ecosystem model that includes permafrost carbon dynamics, inhibition of respiration in frozen soil layers, vertical mixing of soil carbon from surface to permafrost layers, and CH4 emissions from flooded areas, and which better matches new circumpolar inventories of soil carbon stocks, to explore the potential for carbon-climate feedbacks at high latitudes. Contrary to model results for the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4), when permafrost processes are included, terrestrial ecosystems north of 60°N could shift from being a sink to a source of CO2 by the end of the 21st century when forced by a Special Report on Emissions Scenarios (SRES) A2 climate change scenario. Between 1860 and 2100, the model response to combined CO2 fertilization and climate change changes from a sink of 68 Pg to a 27 + -7 Pg sink to 4 + -18 Pg source, depending on the processes and parameter values used. The integrated change in carbon due to climate change shifts from near zero, which is within the range of previous model estimates, to a climate-induced loss of carbon by ecosystems in the range of 25 + -3 to 85 + -16 Pg C, depending on processes included in the model, with a best estimate of a 62 + -7 Pg C loss. Methane emissions from high-latitude regions are calculated to increase from 34 Tg CH4/y to 41-70 Tg CH4/y, with increases due to CO2 fertilization, permafrost thaw, and warming-induced increased CH4 flux densities partially offset by a reduction in wetland extent.
----------------------
Self-Policing Statutes: Do They Reduce Pollution and Save Regulatory Costs?
Santiago Guerrero & Robert Innes
Journal of Law, Economics, & Organization, forthcoming
Abstract:
State-level statutes provide firms that engage in environmental self-audits, and that self-report their environmental violations, a variety of regulatory rewards, including "immunity" from penalties and "privilege" for information contained in self-audits. This article studies a panel of state-level industries from 1989 through 2003, to determine the effects of the different types of statutes on toxic pollution and government inspections. We find that, by encouraging self-auditing, privilege protections tend to reduce pollution and government enforcement activity; however, sweeping immunity protections, by reducing firms' pollution prevention incentives, raise toxic pollution and government inspection oversight.
----------------------
Income inequality and the development of environmental technologies
Francesco Vona & Fabrizio Patriarca
Ecological Economics, 15 September 2011, Pages 2201-2213
Abstract:
Within rich countries, a large dispersion in the capacity of generating environmental innovations appears correlated to the level of inequality. Previous works analyze the relationship between inequality and environmental quality in a static setting. This paper builds a dynamic model more suitable to analyze technological externalities driven by the emergence of a new demand for green products. Under fairly general assumptions on technology and preferences, we show that: 1. the relationship between inequality and environmental innovation is highly non-linear and crucially depends on per-capita income; 2. an excessive inequality harms the development of environmental technologies especially in rich countries. Key to our results is the fact that externalities generated by pioneer consumers of green products benefit the entire population only for relatively low income distances. The empirical analysis robustly confirms our theoretical results, that is: whereas for rich countries inequality negatively affects the diffusion of innovations, per-capita income is paramount in poorer ones.
----------------------
Contributions of the US state park system to nature recreation
Juha Siikamäki
Proceedings of the National Academy of Sciences, 23 August 2011, Pages 14031-14036
Abstract:
Nature recreation in the United States concentrates in publicly provided natural areas. They are costly to establish and maintain, but their societal contributions are difficult to measure. Here, a unique approach is developed to quantifying nature recreation services generated by the US state park system. The assessment first uses data from five national surveys conducted between 1975 and 2007 to consistently measure the amount of time used for nature recreation. The surveys comprise two official federal surveys and their predecessors. Each survey was designed to elicit nationally representative, detailed data on how people divide their time into different activities. State-level data on time use for nature recreation were then matched with information on the availability of state parks and other potentially important drivers of recreation, so that statistical estimation methods for nonexperimental panel data (difference-in-differences) could be used to examine the net contribution of state parks to nature recreation. The results show that state parks have a robust positive effect on nature recreation. For example, the approximately 2 million acres of state parks established between 1975 and 2007 are estimated to contribute annually 600 million hours of nature recreation (2.7 h per capita, approximately 9% of all nature recreation). All state parks generate annually an estimated 2.2 billion hours of nature recreation (9.7 h per capita; approximately 33% of all nature recreation). Using conventional approaches to valuing time, the estimated time value of nature recreation services generated by the US state park system is approximately $14 billion annually.
----------------------
Sol Hart & Erik Nisbet
Communication Research, forthcoming
Abstract:
The deficit-model of science communication assumes increased communication about science issues will move public consensus toward scientific consensus. However, in the case of climate change, public polarization about the issue has increased in recent years, not diminished. In this study, we draw from theories of motivated reasoning, social identity, and persuasion to examine how science-based messages may increase public polarization on controversial science issues such as climate change. Exposing 240 adults to simulated news stories about possible climate change health impacts on different groups, we found the influence of identification with potential victims was contingent on participants' political partisanship. This partisanship increased the degree of political polarization on support for climate mitigation policies and resulted in a boomerang effect among Republican participants. Implications for understanding the role of motivated reasoning within the context of science communication are discussed.
----------------------
Climate Change, Humidity, and Mortality in the United States
Alan Barreca
Journal of Environmental Economics and Management, forthcoming
Abstract:
This paper estimates the effects of humidity and temperature on mortality rates in the United States (c. 1973-2002) in order to provide insight into the potential health impacts of climate change. I find that humidity, like temperature, is an important determinant of mortality. Coupled with Hadley CM3 climate-change predictions, I project that mortality rates are likely to change little on the aggregate for the United States. However, distributional impacts matter: mortality rates are likely to decline in cold and dry areas, but increase in hot and humid areas. Further, accounting for humidity has important implications for evaluating these distributional effects.
----------------------
Andrew Hackbarth, John Romley & Dana Goldman
Social Science & Medicine, forthcoming
Abstract:
This study investigates racial and ethnic disparities in hospital admission and emergency room visit rates resulting from exposure to ozone and fine particulate matter levels in excess of federal standards ("excess attributable risk"). We generate zip code-level ambient pollution exposures and hospital event rates using state datasets, and use pollution impact estimates in the epidemiological literature to calculate excess attributable risk for racial / ethnic groups in California over 2005-2007. We find that black residents experienced roughly 2.5 times the excess attributable risk of white residents. Hispanic residents were exposed to the highest levels of pollution, but experienced similar excess attributable risk to whites. Asian / Pacific Islander residents had substantially lower excess attributable risk compared to white. We estimate the distinct contributions of exposure and other factors to these results, and find that factors other than exposure can be critical determinants of pollution-related disparities.