Water world
Preventing Prevention
Sean Gailmard & John Patty
American Journal of Political Science, forthcoming
Abstract:
Preventing climate change and damage from natural disasters typically requires policies with up‐front costs that promise a flow of benefits over time. Why has obtaining such policies in a competitive electoral democracy proved so intractable? We develop a formal model of electoral accountability in this context, in which politicians have private information about their motivations. The model shows why fully rational voters, though certain that incumbents spend less on disaster prevention than is good for them, reelect incumbents at very high rates. In addition, in such equilibria, voters would punish incumbents who spent more on disaster prevention. This equilibrium is consistent with (and implies) some of the major empirical regularities observed in the literature on voting and disaster prevention. We discuss some implications of our analysis for advancing public debates about disaster and climate change mitigation.
Leveraging cognitive consistency to nudge conservative climate change beliefs
Hunter Gehlbach, Carly Robinson & Christine Vriesema
Journal of Environmental Psychology, forthcoming
Abstract:
People feel motivated to maintain consistency across many domains in life. When it comes to climate change, many find themselves motivated to maintain consistency with others, e.g., by doubting climate change to cohere with friends' and neighbors' beliefs. The resulting climate skepticism has derailed discussions to address the issue collectively in the United States. To counteract these social consistency pressures, we developed a cognitive consistency intervention for climate skeptics. We first demonstrated that most people share substantial faith in a variety of scientific findings, across disciplines ranging from medicine to astronomy. Next, we show that conservative participants who first acknowledge several general contributions of science subsequently report significantly stronger beliefs in climate science (as compared to conservatives who are asked only about their climate science beliefs). These findings provide an encouraging proof-of-concept for how an inclusive climate conversation might be initiated across the political divide.
Exploring the Environmental Justice Implications of Hurricane Harvey Flooding in Greater Houston, Texas
Jayajit Chakraborty, Timothy Collins & Sara Grineski
American Journal of Public Health, February 2019, Pages 244-250
Methods: Our study integrated cartographic information from Harvey’s Inundation Footprint, developed by the US Federal Emergency Management Agency, with sociodemographic data from the 2012–2016 American Community Survey. Statistical analyses were based on bivariate correlations and multivariate generalized estimating equations.
Results: The areal extent of Harvey-induced flooding was significantly greater in neighborhoods with a higher proportion of non-Hispanic Black and socioeconomically deprived residents after we controlled for contextual factors and clustering.
Why Has China Overinvested in Coal Power?
Mengjia Ren et al.
NBER Working Paper, January 2019
Abstract:
Since 2005, the Chinese government has engaged in an ambitious effort to move China’s energy system away from coal and towards more environmentally friendly sources of energy. However, China’s investment in coal power has accelerated sharply in recent years, raising concerns of massive overcapacity and undermining the central policy goal of promoting cleaner energy. In this paper, we ask why China engaged in such a pronounced investment boom in coal power in the mid-2010s. We find the protective rules under which China’s coal power industry has historically operated have made excessive investment extremely likely unless the central government serves as a “gatekeeper,” slowing and limiting investment in the face of incentives for socially excessive entry. When coal-power project approval authority was decentralized from the central government to local governments at the end of 2014, the gate was lifted and approval time considerably shortened, allowing investment to flood into the market. We construct a simple economic model that elucidates the effects of key policies on coal power investment, and examine the model’s predictions using coal-power project approval records from 2013 to 2016. We find the approval rate of coal power is about 3 times higher when the approval authority is decentralized, and provinces with larger coal industries tend to approve more coal power. We estimate that local coal production accounts for an additional 54GW of approved coal power in 2015 (other things equal), which is about 1/4 of total approved capacity in that year.
Spatial Correlation, Trade, and Inequality: Evidence from the Global Climate
Jonathan Dingel, Kyle Meng & Solomon Hsiang
NBER Working Paper, January 2019
Abstract:
This paper shows that greater global spatial correlation of productivities can increase cross-country welfare dispersion by increasing the correlation between a country’s productivity and its gains from trade. We causally validate this general-equilibrium prediction using a global climatic phenomenon as a natural experiment. We find that gains from trade in cereals over the last half-century were larger for more productive countries and smaller for less productive countries when cereal productivity was more spatially correlated. Incorporating this general-equilibrium effect into a projection of climate-change impacts raises projected international inequality, with higher welfare losses across most of Africa.
Origin of spatial variation in US East Coast sea-level trends during 1900–2017
Christopher Piecuch et al.
Nature, 20 December 2018, Pages 400–404
Abstract:
Identifying the causes of historical trends in relative sea level — the height of the sea surface relative to Earth’s crust — is a prerequisite for predicting future changes. Rates of change along the eastern coast of the USA (the US East Coast) during the past century were spatially variable, and relative sea level rose faster along the Mid-Atlantic Bight than along the South Atlantic Bight and the Gulf of Maine. Past studies suggest that Earth’s ongoing response to the last deglaciation, surface redistribution of ice and water and changes in ocean circulation contributed considerably to this large-scale spatial pattern. Here we analyse instrumental data and proxy reconstructions using probabilistic methods to show that vertical motions of Earth’s crust exerted the dominant control on regional spatial differences in relative sea-level trends along the US East Coast during 1900–2017, explaining most of the large-scale spatial variance. Rates of coastal subsidence caused by ongoing relaxation of the peripheral forebulge associated with the last deglaciation are strongest near North Carolina, Maryland and Virginia. Such structure indicates that Earth’s elastic lithosphere is thicker than has been assumed in other models. We also find a substantial coastal gradient in relative sea-level trends over this period that is unrelated to deglaciation and suggests contributions from twentieth-century redistribution of ice and water. Our results indicate that the majority of large-scale spatial variation in long-term rates of relative sea-level rise on the US East Coast is due to geological processes that will persist at similar rates for centuries.
Projecting Changes in Societally Impactful Northeastern U.S. Snowstorms
Colin Zarzycki
Geophysical Research Letters, 16 November 2018, Pages 12067-12075
Abstract:
The northeastern United States is vulnerable to many impacts from snowfall‐producing winter cyclones that are amplified by the proximity of population centers to storm tracks. Historically, climatic snowfall assessments have centered around seasonal means even though local impacts typically occur at scales of hours to days. To detect snowstorms at the event level, an objective algorithm is defined based on the Regional Snowfall Index. The metric collocates storm snowfall with population to produce statistics of snowstorms with societal impacts. When applied to the Community Earth System Model Large Ensemble, broad declines in snowstorm frequency are projected by the later 21st century. These decreases are primarily due to a warmer atmosphere less conducive to snowfall as the predominant precipitation type. However, reductions are less significant for major events, since more hostile thermodynamic environments are partially offset by increased precipitation associated with cyclones that dynamically drive high‐impact snowstorms.
Four decades of Antarctic Ice Sheet mass balance from 1979–2017
Eric Rignot et al.
Proceedings of the National Academy of Sciences, 22 January 2019, Pages 1095-1103
Abstract:
We use updated drainage inventory, ice thickness, and ice velocity data to calculate the grounding line ice discharge of 176 basins draining the Antarctic Ice Sheet from 1979 to 2017. We compare the results with a surface mass balance model to deduce the ice sheet mass balance. The total mass loss increased from 40 ± 9 Gt/y in 1979–1990 to 50 ± 14 Gt/y in 1989–2000, 166 ± 18 Gt/y in 1999–2009, and 252 ± 26 Gt/y in 2009–2017. In 2009–2017, the mass loss was dominated by the Amundsen/Bellingshausen Sea sectors, in West Antarctica (159 ± 8 Gt/y), Wilkes Land, in East Antarctica (51 ± 13 Gt/y), and West and Northeast Peninsula (42 ± 5 Gt/y). The contribution to sea-level rise from Antarctica averaged 3.6 ± 0.5 mm per decade with a cumulative 14.0 ± 2.0 mm since 1979, including 6.9 ± 0.6 mm from West Antarctica, 4.4 ± 0.9 mm from East Antarctica, and 2.5 ± 0.4 mm from the Peninsula (i.e., East Antarctica is a major participant in the mass loss). During the entire period, the mass loss concentrated in areas closest to warm, salty, subsurface, circumpolar deep water (CDW), that is, consistent with enhanced polar westerlies pushing CDW toward Antarctica to melt its floating ice shelves, destabilize the glaciers, and raise sea level.
A recent increase in global wave power as a consequence of oceanic warming
Borja Reguero, Iñigo Losada & Fernando Méndez
Nature Communications, January 2019
Abstract:
Wind-generated ocean waves drive important coastal processes that determine flooding and erosion. Ocean warming has been one factor affecting waves globally. Most studies have focused on studying parameters such as wave heights, but a systematic, global and long-term signal of climate change in global wave behavior remains undetermined. Here we show that the global wave power, which is the transport of the energy transferred from the wind into sea-surface motion, has increased globally (0.4% per year) and by ocean basins since 1948. We also find long-term correlations and statistical dependency with sea surface temperatures, globally and by ocean sub-basins, particularly between the tropical Atlantic temperatures and the wave power in high south latitudes, the most energetic region globally. Results indicate the upper-ocean warming, a consequence of anthropogenic global warming, is changing the global wave climate, making waves stronger. This identifies wave power as a potentially valuable climate change indicator.
Attribution of the Influence of Human‐Induced Climate Change on an Extreme Fire Season
Megan Kirchmeier‐Young et al.
Earth's Future, forthcoming
Abstract:
A record 1.2 million ha burned in British Columbia, Canada's extreme wildfire season of 2017. Key factors in this unprecedented event were the extreme warm and dry conditions that prevailed at the time, which are also reflected in extreme fire weather and behavior metrics. Using an event attribution method and a large ensemble of regional climate model simulations, we show that the risk factors affecting the event, and the area burned itself, were made substantially greater by anthropogenic climate change. We show over 95% of the probability for the observed maximum temperature anomalies is due to anthropogenic factors, that the event's high fire weather/behavior metrics were made 2–4 times more likely, and that anthropogenic climate change increased the area burned by a factor of 7–11. This profound influence of climate change on forest fire extremes in British Columbia, which is likely reflected in other regions and expected to intensify in the future, will require increasing attention in forest management, public health, and infrastructure.
The Influence of Interannual Climate Variability on Regional Violent Crime Rates in the United States
Ryan Harp & Kristopher Karnauskas
GeoHealth, November 2018, Pages 356-369
Abstract:
While the impact of climate on regional geopolitical stability and large‐scale conflict has garnered increased visibility in recent years, the effects of climate variability on interpersonal violent crime have received only limited scientific attention. Though earlier studies have established a modest correlation between temperature and violent crime, the underlying seasonality in both variables was not controlled for and spatial heterogeneity of the statistical relationships have largely been overlooked. Here, a method of spatial aggregation is applied to the United States, enabling a systematic investigation into the observed relationships between large‐scale climate variability and regionally‐aggregated crime rates. This novel approach allows for differentiation between the effects of two previously proposed mechanisms linking climate and violent crime, the Routine Activities Theory and Temperature‐Aggression Hypothesis. Results indicate large and statistically significant positive correlations between the interannual variability of wintertime air temperature and both violent and property crime rates, with negligible correlations emerging from summertime data. Results strongly support the Routine Activities Theory linking climate and violent crime, with climate variability explaining well over a third of the variance of wintertime aggravated assault in several broad regions of the United States. Finally, results motivate the development of observationally constrained empirical models and their potential application to seasonal and potentially longer‐term forecasts.
Carbon Emissions and Business Cycles
Hashmat Khan et al.
Journal of Macroeconomics, June 2019, Pages 1-19
Abstract:
Carbon emissions and real GDP are strongly correlated over the U.S. business cycle. This relationship suggests that macroeconomic shocks inducing cyclical fluctuations in output should also account for the cyclical behavior of emissions and motivates our analysis. We begin by expanding the set of technology shocks in a popular emissions-augmented dynamic stochastic general equilibrium model from the literature, and show that the model generates positive emissions-GDP comovements to each shock through distinct channels. We then estimate the emissions’ response to empirically identified technology shocks using structural vector autoregressions (SVARs). Using the SVARs, we also rank the shocks in terms of explaining the emissions’ forecast error variation. While emissions tend to rise gradually after most shocks, consistent with their theoretical counterparts, the impulse responses are not statistically significant. Unanticipated technology shocks account for less than 10 percent of the variation in emissions. By contrast, anticipated investment technology shocks account for 25 percent of the variation. Government spending and monetary policy shocks account for less than 1 percent. Importantly, close to two thirds of the variation in emissions appears to be due to a structural shock not yet identified in the literature.