Rain or shine
Higher temperatures increase suicide rates in the United States and Mexico
Marshall Burke et al.
Nature Climate Change, forthcoming
Abstract:
Linkages between climate and mental health are often theorized but remain poorly quantified. In particular, it is unknown whether the rate of suicide, a leading cause of death globally, is systematically affected by climatic conditions. Using comprehensive data from multiple decades for both the United States and Mexico, we find that suicide rates rise 0.7% in US counties and 2.1% in Mexican municipalities for a 1 °C increase in monthly average temperature. This effect is similar in hotter versus cooler regions and has not diminished over time, indicating limited historical adaptation. Analysis of depressive language in >600 million social media updates further suggests that mental well-being deteriorates during warmer periods. We project that unmitigated climate change (RCP8.5) could result in a combined 9–40 thousand additional suicides (95% confidence interval) across the United States and Mexico by 2050, representing a change in suicide rates comparable to the estimated impact of economic recessions, suicide prevention programmes or gun restriction laws.
Rising Sea Levels and Sinking Property Values: Hurricane Sandy and New York’s Housing Market
Francesc Ortega & Süleyman Taṣpınar
Journal of Urban Economics, July 2018, Pages 81-100
Abstract:
This paper analyzes the effects of hurricane Sandy on the New York City housing market using a large parcel-level dataset that contains all housing sales for 2003-2017. The dataset also contains geo-coded FEMA data on which building structures were damaged by the hurricane and to what degree. Our estimates provide robust evidence of a persistent negative impact on flood zone housing values. We show the gradual emergence of a price penalty among flood zone properties that were not damaged by Sandy, reaching 8% in year 2017 and showing no signs of recovery. In contrast, damaged properties suffered a large immediate drop in value following the storm (17-22%), followed by a partial recovery and convergence toward a similar penalty as non-damaged properties. The partial recovery in the prices of damaged properties likely reflects their gradual restoration. However, the persistent price reduction affecting all flood-zone properties is more consistent with a learning mechanism. Hurricane Sandy may have increased the perceived risk of large-scale flooding episodes in that area.
Relationships among conspiratorial beliefs, conservatism and climate scepticism across nations
Matthew Hornsey, Emily Harris & Kelly Fielding
Nature Climate Change, July 2018, Pages 614–620
Abstract:
Studies showing that scepticism about anthropogenic climate change is shaped, in part, by conspiratorial and conservative ideologies are based on data primarily collected in the United States. Thus, it may be that the ideological nature of climate change beliefs reflects something distinctive about the United States rather than being an international phenomenon. Here we find that positive correlations between climate scepticism and indices of ideology were stronger and more consistent in the United States than in the other 24 nations tested. This suggests that there is a political culture in the United States that offers particularly strong encouragement for citizens to appraise climate science through the lens of their worldviews. Furthermore, the weak relationships between ideology and climate scepticism in the majority of nations suggest that there is little inherent to conspiratorial ideation or conservative ideologies that predisposes people to reject climate science, a finding that has encouraging implications for climate mitigation efforts globally.
The climate lobby: A sectoral analysis of lobbying spending on climate change in the USA, 2000 to 2016
Robert Brulle
Climatic Change, forthcoming
Abstract:
Lobbying is considered to be an important factor in the success or failure of climate change legislation. This paper provides an estimate of lobbying expenditures related to climate change legislation in the U.S. Congress from 2000 to 2016. During this time period, over $2 billion was spent on this activity, constituting 3.9% of total lobbying expenditures. Major sectors involved in lobbying were fossil fuel and transportation corporations, utilities, and affiliated trade associations. Expenditures by these sectors dwarf those of environmental organizations and renewable energy corporations. Levels of expenditures on lobbying appear to be related to the introduction and probability of passage of significant climate legislation. Future research should focus on tying particular positions on climate legislation and lobbying expenditures at the corporate level.
Lights Out: Climate Change Risk to Internet Infrastructure
Ramakrishnan Durairajan, Carol Barford & Paul Barford
University of Oregon Working Paper, July 2018
Abstract:
In this paper we consider the risks to Internet infrastructure in the US due to sea level rise. Our study is based on sea level incursion projections from the National Oceanic and Atmospheric Administration (NOAA) and Internet infrastructure deployment data from Internet Atlas. We align the data formats and assess risks in terms of the amount and type of infrastructure that will be under water in different time intervals over the next 100 years. We find that 4,067 miles of fiber conduit will be under water and 1,101 nodes (e.g., points of presence and colocation centers) will be surrounded by water in the next 15 years. We further quantify the risks of sea level rise by defining a metric that considers the combination of geographic scope and Internet infrastructure density. We use this metric to examine different regions and find that the New York, Miami, and Seattle metropolitan areas are at highest risk. We also quantify the risks to individual service provider infrastructures and find that CenturyLink, Inteliquent, and AT&T are at highest risk. While it is difficult to project the impact of countermeasures such as sea walls, our results suggest the urgency of developing mitigation strategies and alternative infrastructure deployments.
The Effects of Climate Change on GDP by Country and the Global Economic Gains from Complying with the Paris Climate Accord
Tom Kompas, Pham Van Ha & Tuong Nhu Che
Earth's Future, forthcoming
Abstract:
Computable General Equilibrium (CGE) models are a standard tool for policy analysis and forecasts of economic growth. Unfortunately, due to computational constraints, many CGE models are dimensionally small, aggregating countries into an often limited set of regions, or using assumptions such as static price level expectations, where next period's price is conditional only on current or past prices. This is a concern for climate change modeling, since the effects of global warming by country, in a fully disaggregated and global trade model, are needed, and the known future effects of global warming should be included in forward‐looking forecasts for prices and profitability. This work extends a large dimensional intertemporal CGE trade model to account for the various effects of global warming (e.g., loss in agricultural productivity, sea level rise, and health effects) on GDP growth and levels for 139 countries, by decade and over the long term, where producers look forward and adjust price expectations and capital stocks to account for future climate effects. The potential economic gains from complying with the Paris Accord are also estimated, showing that even with a limited set of possible damages from global warming, these gains are substantial. For example, with the comparative case of RCP 8.5 (4C), the global gains from complying with the 2C target (RCP 4.5), are approximately US$17,489 billion per year in the long run (year 2100). The relative damages from not complying to Sub‐Sahara Africa, India and Southeast Asia, across all temperature ranges, are especially severe.
Maybe Next Month? Temperature Shocks and Dynamic Adjustments in Birth Rates
Alan Barreca, Olivier Deschenes & Melanie Guldi
Demography, August 2018, Pages 1269–1293
Abstract:
We estimate the effects of temperature shocks on birth rates in the United States between 1931 and 2010. We find that days with a mean temperature above 80°F cause a large decline in birth rates 8 to 10 months later. Unlike prior studies, we demonstrate that the initial decline is followed by a partial rebound in births over the next few months, implying that populations mitigate some of the fertility cost by shifting conception month. This shift helps explain the observed peak in late-summer births in the United States. We also present new evidence that hot weather most likely harms fertility via reproductive health as opposed to sexual activity. Historical evidence suggests that air conditioning could be used to substantially offset the fertility costs of high temperatures.
Tornado Damage Mitigation: Homeowner Support for Enhanced Building Codes in Oklahoma
Joseph Ripberger et al.
Risk Analysis, forthcoming
Abstract:
Tornadoes impose enormous costs on society. Relatively simple and inexpensive enhancements to building codes may reduce these costs by 30% or more, but only one city in the United States has adopted these codes. Why is this the case? This analysis addresses this question by examining homeowner support for more stringent building codes in Oklahoma, a conservative state that routinely experiences damaging tornadoes. Survey data show that support for mandatory mitigation policies like building codes is subject to countervailing forces. Push dynamics, including objective risk data, homeowners’ risk perceptions, and damage experience, encourage support for mitigation. Pull dynamics, such as individualistic and conservative worldviews, and skepticism about climate change, generate opposition. At the margin, the pull dynamics appear to exert more force than push dynamics, creating only a weak basis of support that is not strong enough to overcome the status quo bias in a state that is cautious about regulatory measures. The concluding section offers suggestions for changing these dynamics.
Using archived television video footage to quantify phenology responses to climate change
Pieter De Frenne et al.
Methods in Ecology and Evolution, forthcoming
Abstract:
Predicting how the timing of cyclic life‐history events, such as leafing and flowering, respond to climate change is of paramount importance due to the cascading impacts of vegetation phenology on species and ecosystem fitness. However, progress of this field is hampered by the relative scarcity, and geographic and phylogenetic bias, of long‐term phenology datasets. By taking advantage of archived television video footage, we here developed an innovative tool using previously unexploited records to build long‐term datasets of phenological responses. To demonstrate the potential of this method, we worked with broadcast archives of sport events and focus on one of the most famous professional road cycling races world‐wide, the Tour of Flanders. After viewing >200 hr of film, we compiled 523 individual × year observations of leaf‐out and flowering of 46 individual trees and shrubs visible in four decades (1981–2016) of video footage. We detect surprisingly strong advances in the timing of tree leaf‐out and flowering in the footage: trees almost never had flushed at the time of the spring race in the 1980s while significantly more individuals had flushed in the video footage between 2006 and 2016 (probabilities of leafing and flowering increased by 19% and 67%, respectively). These shifts were most strongly related to January–March temperatures and growing‐degree hours (cumulative heat) in the preceding months. We demonstrate that this technical advance offers key benefits to fill gaps in existing phenology time series and reveal that archived video footage can indeed be applied to determine species‐temperature relationships with high spatiotemporal resolution. Only by compiling more data from the past will we be able to further our understanding on the effects of climate change on species and ecosystems in the future.
Flood damage costs under the sea level rise with warming of 1.5 °C and 2 °C
Svetlana Jevrejeva et al.
Environmental Research Letters, July 2018
Abstract:
We estimate a median global sea level rise up to 52 cm (25–87 cm, 5th–95th percentile) and up to 63 cm (27−112 cm, 5th—95th percentile) for a temperature rise of 1.5 °C and 2.0 °C by 2100 respectively. We also estimate global annual flood costs under these scenarios and find the difference of 11 cm global sea level rise in 2100 could result in additional losses of US$ 1.4 trillion per year (0.25% of global GDP) if no additional adaptation is assumed from the modelled adaptation in the base year. If warming is not kept to 2 °C, but follows a high emissions scenario (Representative Concentration Pathway 8.5), global annual flood costs without additional adaptation could increase to US$ 14 trillion per year and US$ 27 trillion per year for global sea level rise of 86 cm (median) and 180 cm (95th percentile), reaching 2.8% of global GDP in 2100. Upper middle income countries are projected to experience the largest increase in annual flood costs (up to 8% GDP) with a large proportion attributed to China. High income countries have lower projected flood costs, in part due to their high present-day protection standards. Adaptation could potentially reduce sea level induced flood costs by a factor of 10. Failing to achieve the global mean temperature targets of 1.5 °C or 2 °C will lead to greater damage and higher levels of coastal flood risk worldwide.
Variable Pricing and the Cost of Renewable Energy
Imelda, Matthias Fripp & Michael Roberts
NBER Working Paper, June 2018
Abstract:
On a levelized-cost basis, solar and wind power generation are now competitive with fossil fuels. But supply of these renewable resources is variable and intermittent, unlike traditional power plants. As a result, the cost of using flat retail pricing instead of dynamic, marginal-cost pricing — long advocated by economists — will grow. We evaluate the potential gains from dynamic pricing in high-renewable systems using a novel model of power supply and demand in Hawai’i. The model breaks new ground in integrating investment in generation and storage capacity with chronological operation of the system, including an account of reserves, a demand system with different interhour elasticities for different uses, and substitution between power and other goods and services. The model is open source and fully adaptable to other settings. Consistent with earlier studies, we find that dynamic pricing provides little social benefit in fossil-fuel-dominated power systems, only 2.6 to 4.6 percent of baseline annual expenditure. But dynamic pricing leads to a much greater social benefit of 8.5 to 23.4 percent in a 100 percent renewable power system with otherwise similar assumptions. High renewable systems, including 100 percent renewable, are remarkably affordable. The welfare maximizing (unconstrained) generation portfolio under the utility’s projected 2045 technology and pessimistic interhour demand flexibility uses 79 percent renewable energy, without even accounting for pollution externalities. If overall demand for electricity is more elastic than our baseline (0.1), renewable energy is even cheaper and variable pricing can improve welfare by as much as 47 percent of baseline expenditure.
Optimal Climate Policy and the Future of World Economic Development
Mark Budolfson et al.
World Bank Economic Review, forthcoming
Abstract:
How much should the present generations sacrifice to reduce emissions today, in order to reduce the future harms of climate change? Within climate economics, debate on this question has been focused on so-called “ethical parameters” of social time preference and inequality aversion. We show that optimal climate policy similarly importantly depends on the future of the developing world. In particular, although global poverty is falling and the economic lives of the poor are improving worldwide, leading models of climate economics may be too optimistic about two central predictions: future population growth in poor countries, and future convergence in total factor productivity (TFP). We report results of small modifications to a standard model: under plausible scenarios for high future population growth (especially in sub-Saharan Africa) and for low future TFP convergence, we find that optimal near-term carbon taxes could be substantially larger.
Reduced cognitive function during a heat wave among residents of non-air-conditioned buildings: An observational study of young adults in the summer of 2016
Jose Guillermo Cedeño Laurent et al.
PLoS Medicine, July 2018
Methods: We followed 44 students (mean age = 20.2 years; SD = 1.8 years) from a university in the Greater Boston area, Massachusetts in the United States living in AC (n = 24) and non-AC (n = 20) buildings before, during, and after a HW [heat wave]. Two cognition tests were self-administered daily for a period of 12 days (July 9–July 20, 2016), the Stroop color-word test (STROOP) to assess selective attention/processing speed and a 2-digit, visual addition/subtraction test (ADD) to evaluate cognitive speed and working memory. The effect of the HW on cognitive function was evaluated using difference-in-differences (DiD) modelling.
Findings: Mean indoor temperatures in the non-AC group (mean = 26.3°C; SD = 2.5°C; range = 19.6–30.4°C) were significantly higher (p < 0.001) than in the AC group (mean = 21.4°C; SD = 1.9°C; range = 17.5–25.0°C). DiD estimates show an increase in reaction time (STROOP = 13.4%, p < 0001; ADD = 13.3%, p < 0.001) and reduction in throughput (STROOP = −9.9%, p < 0.001; ADD = −6.3%, p = 0.08) during HWs among non-AC residents relative to AC residents at baseline. While ADD showed a linear relationship with indoor temperatures, STROOP was described by a U-shaped curve with linear effects below and above an optimum range (indoor temperature = 22°C–23°C), with an increase in reaction time of 16 ms/°C and 24 ms/°C for STROOP and ADD, respectively. Cognitive tests occurred right after waking, so the study is limited in that it cannot assess whether the observed effects extended during the rest of the day. Although the range of students’ ages also represents a limitation of the study, the consistent findings in this young, healthy population might indicate that greater portions of the population are susceptible to the effects of extreme heat.
Global surface warming enhanced by weak Atlantic overturning circulation
Xianyao Chen & Ka-Kit Tung
Nature, 19 July 2018, Pages 387–391
Abstract:
Evidence from palaeoclimatology suggests that abrupt Northern Hemisphere cold events are linked to weakening of the Atlantic Meridional Overturning Circulation (AMOC), potentially by excess inputs of fresh water. But these insights — often derived from model runs under preindustrial conditions — may not apply to the modern era with our rapid emissions of greenhouse gases. If they do, then a weakened AMOC, as in 1975–1998, should have led to Northern Hemisphere cooling. Here we show that, instead, the AMOC minimum was a period of rapid surface warming. More generally, in the presence of greenhouse-gas heating, the AMOC’s dominant role changed from transporting surface heat northwards, warming Europe and North America, to storing heat in the deeper Atlantic, buffering surface warming for the planet as a whole. During an accelerating phase from the mid-1990s to the early 2000s, the AMOC stored about half of excess heat globally, contributing to the global-warming slowdown. By contrast, since mooring observations began in 2004, the AMOC and oceanic heat uptake have weakened. Our results, based on several independent indices, show that AMOC changes since the 1940s are best explained by multidecadal variability, rather than an anthropogenically forced trend. Leading indicators in the subpolar North Atlantic today suggest that the current AMOC decline is ending. We expect a prolonged AMOC minimum, probably lasting about two decades. If prior patterns hold, the resulting low levels of oceanic heat uptake will manifest as a period of rapid global surface warming.
A global slowdown of tropical-cyclone translation speed
James Kossin
Nature, 7 June 2018, Pages 104–107
Abstract:
As the Earth’s atmosphere warms, the atmospheric circulation changes. These changes vary by region and time of year, but there is evidence that anthropogenic warming causes a general weakening of summertime tropical circulation. Because tropical cyclones are carried along within their ambient environmental wind, there is a plausible a priori expectation that the translation speed of tropical cyclones has slowed with warming. In addition to circulation changes, anthropogenic warming causes increases in atmospheric water-vapour capacity, which are generally expected to increase precipitation rates. Rain rates near the centres of tropical cyclones are also expected to increase with increasing global temperatures. The amount of tropical-cyclone-related rainfall that any given local area will experience is proportional to the rain rates and inversely proportional to the translation speeds of tropical cyclones. Here I show that tropical-cyclone translation speed has decreased globally by 10 per cent over the period 1949–2016, which is very likely to have compounded, and possibly dominated, any increases in local rainfall totals that may have occurred as a result of increased tropical-cyclone rain rates. The magnitude of the slowdown varies substantially by region and by latitude, but is generally consistent with expected changes in atmospheric circulation forced by anthropogenic emissions. Of particular importance is the slowdown of 30 per cent and 20 per cent over land areas affected by western North Pacific and North Atlantic tropical cyclones, respectively, and the slowdown of 19 per cent over land areas in the Australian region. The unprecedented rainfall totals associated with the ‘stall’ of Hurricane Harvey over Texas in 2017 provide a notable example of the relationship between regional rainfall amounts and tropical-cyclone translation speed. Any systematic past or future change in the translation speed of tropical cyclones, particularly over land, is therefore highly relevant when considering potential changes in local rainfall totals.
The global potential for converting renewable electricity to negative-CO2-emissions hydrogen
Greg Rau, Heather Willauer & Zhiyong Jason Ren
Nature Climate Change, July 2018, Pages 621–625
Abstract:
The IPCC has assigned a critical role to negative-CO2-emissions energy in meeting energy and climate goals by the end of the century, with biomass energy plus carbon capture and storage (BECCS) prominently featured. We estimate that methods of combining saline water electrolysis with mineral weathering powered by any source of non-fossil fuel-derived electricity could, on average, increase energy generation and CO2 removal by >50 times relative to BECCS, at equivalent or lower cost. This electrogeochemistry avoids the need to produce and store concentrated CO2, instead converting and sequestering CO2 as already abundant, long-lived forms of ocean alkalinity. Such energy systems could also greatly reduce land and freshwater impacts relative to BECCS, and could also be integrated into conventional energy production to reduce its carbon footprint. Further research is needed to better understand the full range and capacity of the world’s negative-emissions options.
Mass balance of the Antarctic Ice Sheet from 1992 to 2017
Andrew Shepherd et al.
Nature, 14 June 2018, Pages 219–222
Abstract:
The Antarctic Ice Sheet is an important indicator of climate change and driver of sea-level rise. Here we combine satellite observations of its changing volume, flow and gravitational attraction with modelling of its surface mass balance to show that it lost 2,720 ± 1,390 billion tonnes of ice between 1992 and 2017, which corresponds to an increase in mean sea level of 7.6 ± 3.9 millimetres (errors are one standard deviation). Over this period, ocean-driven melting has caused rates of ice loss from West Antarctica to increase from 53 ± 29 billion to 159 ± 26 billion tonnes per year; ice-shelf collapse has increased the rate of ice loss from the Antarctic Peninsula from 7 ± 13 billion to 33 ± 16 billion tonnes per year. We find large variations in and among model estimates of surface mass balance and glacial isostatic adjustment for East Antarctica, with its average rate of mass gain over the period 1992–2017 (5 ± 46 billion tonnes per year) being the least certain.