BACKGROUND:Studies have documented the effect of increased nuisance high-tide flooding on traffic disruption and delays as well as infrastructure maintenance and repair costs. Recent research suggests that high-tide flooding is also associated with more extreme outcomes, including increased mortality risk among adults aged 65 years and older. The aim of this study was to leverage these new findings to project future premature deaths and associated economic costs among older adults in coastal areas of the USA throughout the 21st century under various climate change scenarios. METHODS:We estimated the relationship between global sea level rise and high-tide flooding. We then employed five projections of relative mean sea level from the Fifth National Climate Assessment to develop a probabilistic distribution of high-tide flooding scenarios. Combining population and baseline mortality projections with published estimates of the association between high-tide flooding and premature mortality among adults aged 65 years and older in Florida, USA, we generated a distribution of predicted high-tide flooding mortality impacts across coastal areas of the USA. Because this analysis assumes no change in adaptation strategies, we also presented a stylised scenario that assumes additional action is taken to limit mortality risk. FINDINGS:Our main specification (without additional adaptation) anticipates approximately 230 additional deaths of older adults per year in 2020 relative to 2005, corresponding to monetised damages of US$3·1 billion. By 2100, the model projects nearly 10 000 additional deaths in this age group per year under the same scenario, a 43-fold increase relative to modelled 2005 levels. With some protective measures, the model predicts 5700 additional premature deaths, representing a 57% reduction relative to the main results. INTERPRETATION:The cost of premature mortality in older adults is greater in magnitude than other modelled effects of climate-induced high-tide flooding (eg, value of lost time due to traffic delays). Results suggest further action is needed to (1) identify and protect components of road networks critical for emergency access, (2) build additional, more accessible critical care delivery facilities, and (3) manage the retreat of vulnerable populations to areas with better access to critical care facilities. FUNDING:US Environmental Protection Agency.

The desire of policymakers and public finance institutions to understand the contribution of water infrastructure to the wider economy, rather than the value of project-level outputs in isolation, has spawned a multidisciplinary branch of water resource planning that integrates traditional biophysical modeling of water resource systems with economy-wide models, including computable general equilibrium models. Economy-wide models include several distinct approaches, including input–output models, macro-econometric models, hybrid input–output macro-econometric models, and general equilibrium models—the term “economy-wide” usually refers to a national level analysis, but could also apply to a sub-national region, multi-nation regions, or the world. A key common characteristic of these models is that they disaggregate the overall economy of a country or region into a number of smaller units, or optimizing agents, who in turn interact with other agents in the economy in determining the use of inputs for production, and the outcomes of markets for goods. These economic agents include industries, service providers, households, governments, and many more. Such a holistic general equilibrium modeling approach is particularly useful for understanding and measuring social costs, a key aim in most cost–benefit analyses (CBAs) of water infrastructure investments when the project or program will have non-marginal impacts and current market prices will be impacted and an appropriately detailed social accounting matrix is available. This article draws on examples from recent work on low- and middle-income countries (LMICs) and provides an outline of available resources that are necessary to conduct an economy-wide modeling analysis. LMICs are the focus of larger water resource investment potential in the 21st century, including large-scale hydropower, irrigation, and drinking water supply. A step-by-step approach is illustrated and supports the conclusion that conditions exist to apply these models much more broadly in LMICs to enhance CBAs.

Background: This paper represents, to our knowledge, the first national-level (United States) estimate of the economic impacts of vibriosis cases as exacerbated by climate change. Vibriosis is an illness contracted through food- and waterborne exposures to various Vibrio species (e.g., nonV. cholerae O1 and O139 serotypes) found in estuarine and marine environments, including within aquatic life, such as shellfish and finfish. Objectives: The objective of this study was to project climate-induced changes in vibriosis and associated economic impacts in the United States related to changes in sea surface temperatures (SSTs). Methods: For our analysis to identify climate links to vibriosis incidence, we constructed three logistic regression models by Vibrio species, using vibriosis data sourced from the Cholera and Other Vibrio Illness Surveillance system and historical SSTs. We relied on previous estimates of the cost-per-case of vibriosis to estimate future total annual medical costs, lost income from productivity loss, and mortality-related indirect costs throughout the United States. We separately reported results for V. parahaemolyticus, V. vulnificus, V. alginolyticus, and “V. spp.,” given the different associated health burden of each. Results: By 2090, increases in SST are estimated to result in a 51% increase in cases annually relative to the baseline era (centered on 1995) under Representative Concentration Pathway (RCP) 4.5, and a 108% increase under RCP8.5. The cost of these illnesses is projected to reach $5.2 billion annually under RCP4.5, and $7.3 billion annually under RCP8.5, relative to $2.2 billion in the baseline (2018 U.S. dollars), equivalent to 140% and 234% increases respectively. Discussion: Vibriosis incidence is likely to increase in the United States under moderate and unmitigated climate change scenarios through increases in SST, resulting in a substantial burden of morbidity and mortality, and costing billions of dollars. These costs are mostly attributable to deaths, primarily from exposure to V. vulnificus. Evidence suggests that other factors, including sea surface salinity, may contribute to further increases in vibriosis cases in some regions of the United States and should also be investigated. https://doi.org/10.1289/EHP9999a

Economic and health benefits assessments of air quality changes often quantify and report changes in deaths at a given point in time. The typical approach uses a method that attributes air pollution-related health impacts to a single year air quality change (or “pulse”). The perspective on benefits from these static pulse analyses can be enhanced by conducting a dynamic population assessment using life tables. Such analyses can provide a richer characterization of health risks across a population over a multiyear time horizon. In this article, we use the life table approach to quantify cumulative counts of reductions in PM-attributable deaths and life-years gained due to overlapping impacts of PM2.5 changes over a multiyear period, using case studies of air quality improvements in the USA and Chile. Our comparison of health risk and economic valuation for the two approaches shows life table analysis can be a valuable adjunct analysis to the pulse approach though both come with their own set of uncertainties and limitations. If applied jointly, they provide a broader characterization of how air quality actions can change populations in terms of life-years lost, life expectancy, and age structure. The value of these metrics is illustrated using case studies with dramatically different air quality reduction trajectories.

Sea level rise threatens the coastal landscape, including coastal wetlands, which provide a unique natural habitat to a variety of animal and plant species as well as an array of ecosystem service flows of value to people. The economic valuation of potential changes in coastal wetland areas, while challenging, allows for a comparison with other types of economic impacts from climate change and enhances our understanding of the potential benefits of greenhouse gas mitigation. In this study, we estimate an ensemble of future changes in coastal wetland areas considering both sea level rise, future greenhouse gas emissions, and accretion rate uncertainty, using outputs from the National Ocean and Atmospheric (NOAA) marsh migration model. By the end of the century, total wetland losses range from 2.0 to 10.7 million acres across sea level rise scenarios. For Representative Concentration Pathway (RCP) 4.5 and RCP8.5, respectively, cummulative net wetland area loss is 1.8 and 2.4 million acres by 2050 and 3.5 and 5.2 million acres by 2100. We then estimate economic impacts with two distinct approaches: restoration cost and ecosystem services. The ecosystem services considered are limited by what can be reliably quantified-namely, coastal property protection from coastal flooding and carbon sequestration, the latter using a social cost of carbon approach. By the end of the century, annual restoration costs reach $1.5 and $3.1 billion for RCP 4.5 and RCP8.5, respectively. The lost ecosystem services, together, reach annual economic impacts that are much higher, reaching $2.5 billion for RCP4.5 and $6.1 billion for RCP8.5.

Earth and Space Science Open Archive Presented WorkOpen AccessYou are viewing the latest version by default [v1]The Influence of Climate Change on Vibriosis in the United States: Projected Health and Economic Impacts for the 21st CenturyAuthorsMichaelKolianiDMeganSheahanCaitlinGouldJamesNeumanniDPatrickKinneySandraHoffmannCharlesFantSelinaWangSee all authors Michael KolianiDCorresponding Author• Submitting AuthorEnvironmental Protection Agency Washington DCiDhttps://orcid.org/0000-0002-7134-8317view email addressThe email was not providedcopy email addressMegan SheahanIndustrial Economics, Inc.view email addressThe email was not providedcopy email addressCaitlin GouldEnvironmental Protection Agency Washington DCview email addressThe email was not providedcopy email addressJames NeumanniDIndustrial Economics, Inc.iDhttps://orcid.org/0000-0001-7553-3037view email addressThe email was not providedcopy email addressPatrick KinneyBoston Universityview email addressThe email was not providedcopy email addressSandra HoffmannUS Department of Agriculture Economic Research Serviceview email addressThe email was not providedcopy email addressCharles FantIndustrial Economics, Inc.view email addressThe email was not providedcopy email addressSelina WangTufts Universityview email addressThe email was not providedcopy email address

Changes in temperature, precipitation, sea level, and coastal storms will likely increase the vulnerability of infrastructure across the USA. Using models that analyze vulnerability, impacts, and adaptation, this paper estimates impacts to railroad, roads, and coastal properties under three infrastructure management response scenarios: No Adaptation; Reactive Adaptation, and Proactive Adaptation. Comparing damages under each of these potential responses provides strong support for facilitating effective adaptation in these three sectors. Under a high greenhouse gas emissions scenario and without adaptation, overall costs are projected to range in the $100s of billions annually by the end of this century. The first (reactive) tier of adaptation action, however, reduces costs by a factor of 10, and the second (proactive) tier reduces total costs across all three sectors to the low $10s of billions annually. For the rail and road sectors, estimated costs for Reactive and Proactive Adaptation scenarios capture a broader share of potential impacts, including selected indirect costs to rail and road users, and so are consistently about a factor of 2 higher than prior estimates. The results highlight the importance of considering climate risks in infrastructure planning and management.

Coccidioidomycosis, or valley fever, is an infectious fungal disease currently endemic to the southwestern United States. Symptoms of valley fever range in severity from flu-like illness to severe morbidity and mortality. Warming temperatures and changes in precipitation patterns may cause the area of endemicity to expand northward throughout the western United States, putting more people at risk for contracting valley fever. This may increase the health and economic burdens from this disease. We developed an approach to describe the relationship between climate conditions and valley fever incidence using historical data and generated projections of future incidence in response to both climate change and population trends using the Climate Change Impacts and Risk Analysis (CIRA) framework developed by the U.S. Environmental Protection Agency. We also developed a method to estimate economic impacts of valley fever that is based on case counts. For our 2000-15 baseline time period, we estimated annual medical costs, lost income, and economic welfare losses for valley fever in the United States were $400,000 per case, and the annual average total cost was $3.9 billion per year. For a high greenhouse gas emission scenario and accounting for population growth, we found that total annual costs for valley fever may increase up to 164% by year 2050 and up to 380% by 2090. By the end of the twenty-first century, valley fever may cost $620,000 per case and the annual average total cost may reach $18.5 billion per year. This work contributes to the broader effort to monetize climate change-attributable damages in the United States.

Wildfire activity in the western United States (US) has been increasing, a trend that has been correlated with changing patterns of temperature and precipitation associated with climate change. Health effects associated with exposure to wildfire smoke and fine particulate matter (PM2.5) include short- and long-term premature mortality, hospital admissions, emergency department visits, and other respiratory and cardiovascular incidents. We estimate PM2.5 exposure and health impacts for the entire continental US from current and future western US wildfire activity projected for a range of future climate scenarios through the 21st century. We use a simulation approach to estimate wildfire activity, area burned, fine particulate emissions, air quality concentrations, health effects, and economic valuation of health effects, using established and novel methodologies. We find that climatic factors increase wildfire pollutant emissions by an average of 0.40% per year over the 2006-2100 period under Representative Concentration Pathway (RCP) 4.5 (lower emissions scenarios) and 0.71% per year for RCP8.5. As a consequence, spatially weighted wildfire PM2.5 concentrations more than double for some climate model projections by the end of the 21st century. PM2.5 exposure changes, combined with population projections, result in a wildfire PM2.5-related premature mortality excess burden in the 2090 RCP8.5 scenario that is roughly 3.5 times larger than in the baseline period. The combined effect of increased wildfire activity, population growth, and increase in the valuation of avoided risk of premature mortality over time results in a large increase in total economic impact of wildfire-related PM2.5 mortality and morbidity in the continental US, from roughly $7 billion per year in the baseline period to roughly $36 billion per year in 2090 for RCP4.5, and $43 billion per year in RCP8.5. The climate effect alone accounts for a roughly 60% increase in wildfire PM2.5-related premature mortality in the RCP8.5 scenario, relative to baseline conditions.

High tide flooding (HTF) already affects traffic in many US coastal areas, but the issue will worsen significantly in the future. While studies show that large storm surge events threaten to be ever more costly, less damaging, but more frequent HTF events remain understudied and potentially carry a comparable economic impact. This study advances our understanding of the risks and impacts of HTF on vulnerable traffic corridors using hourly tide gauge water levels, sea-level rise projections, and link-level spatial analysis. It is the first study to estimate HTF economic impacts for varying levels of intervention, including reasonably anticipated driver-initiated rerouting and ancillary protection of adjacent property. The 2020 annual national-level costs of $1.3 to $1.5 billion will increase to $28 to $37 billion in 2050 and $220 to $260 billion in 2100 for medium to high greenhouse gas (GHG) emissions scenarios, respectively. Total costs over the century are $1.0 to $1.3 trillion (discounted 3%). Additional cost-effective protection by building sea walls or raising road surfaces could significantly reduce 2100 costs to $61 to $78 billion, but there remain many barriers to adopting least-cost adaptation decisions, and these gains may only be realized with careful planning and information sharing.

Characterizing the future risks of climate change is a key goal of climate impacts analysis. Temperature binning provides a framework for analyzing sector-specific impacts by degree of warming as an alternative or complement to traditional scenario-based approaches in order to improve communication of results, comparability between studies, and flexibility to facilitate scenario analysis. In this study, we estimate damages for nine climate impact sectors within the contiguous United States (US) using downscaled climate projections from six global climate models, at integer degrees of US national warming. Each sector is analyzed based on socioeconomic conditions for both the beginning and the end of the century. The potential for adaptive measures to decrease damages is also demonstrated for select sectors; differences in damages across adaptation response scenarios within some sectors can be as much as an order of magnitude. Estimated national damages from these sectors based on a reactive adaptation assumption and 2010 socioeconomic conditions range from $600 million annually per degree of national warming for winter recreation to $8 billion annually per degree of national warming for labor impacts. Results are also estimated per degree of global temperature change and for 2090 socioeconomic conditions.

Recent advancements in the availability of models and data to characterize the economic impacts of climate change have improved our ability to project both the physical impacts and economic effects of climate change across economic sectors of the United States. These advancements have in turn provided an opportunity to estimate these impacts across multiple economic sectors using a consistent set of damage functions. These functions can be used to inform decision making regarding the diversity and magnitude of future impacts and how adaptation and other actions can affect the risk of economic impacts. This article shows how damage functions can be developed from the results of detailed modeling studies and then used to estimate future economic impacts. We estimate damage functions based on 15 sectoral impact models that project the economic impacts of climate change on human health, infrastructure, and ecosystems and, with a focus on temperature, apply these functions to changes in economic impacts for seven U.S. regions through 2100. We also discuss the uncertainty of these results. We conclude that, although further research is needed, the methods presented here can be usefully applied to a range of alternative temperature trajectories to estimate the economic effects of climate change.

The text and associated Supplemental Materials contribute internally consistent and therefore entirely comparable regional, temporal, and sectoral risk profiles to a growing literature on regional economic vulnerability to climate change. A large collection of maps populated with graphs of Monte-Carlo simulation results support a communication device in this regard — a convenient visual that we hope will make comparative results tractable and credible and resource allocation decisions more transparent. Since responding to climate change is a risk-management problem, it is important to note that these results address both sides of the risk calculation. They characterize likelihood distributions along four alternative emissions futures (thereby reflecting the mitigation side context); and they characterize consequences along these transient trajectories (which can thereby inform planning for the iterative adaptation side). Looking across the abundance of sectors that are potentially vulnerable to some of the manifestations of climate change, the maps therefore hold the potential of providing comparative information about the magnitude, timing, and regional location of relative risks. This is exactly the information that planners who work to protect property and public welfare by allocating scarce resources across competing venues need to have at their disposal — information about relative vulnerabilities across time and space and contingent on future emissions and future mitigation. It is also the type of information that integrated assessment researchers need to calibrate and update their modeling efforts — scholars who are exemplified by Professor Nordhaus who created and exercised the Dynamic Integrated Climate-Economy and Regional Integrated Climate-Economy models.

The National Coastal Property Model (NCPM) simulates flood damages resulting from sea level rise and storm surge along the contiguous U.S. coastline. The model also projects local-level investments in a set of adaptation measures under the assumption that these measures will be adopted when benefits exceed the costs over a 30-year period. However, it has been observed that individuals and communities often underinvest in adaptive measures relative to standard cost-benefit assumptions due to financial, psychological, sociopolitical, and technological factors. This study applies an updated version of the NCPM to incorporate improved cost-benefit tests and to approximate observed sub-optimal flood risk reduction behavior. The updated NCPM is tested for two multi-county sites: Virginia Beach, VA and Tampa, FL. Sub-optimal adaptation approaches slow the implementation of adaptation measures throughout the 100-year simulation and they increase the amount of flood damages, especially early in the simulation. The net effect is an increase in total present value cost of $1.1 to $1.3 billion (2015 USD), representing about a 10% increase compared to optimal adaptation approaches. Future calibrations against historical data and incorporation of non-economic factors driving adaptation decisions could prove useful in better understanding the impacts of continued sub-optimal behavior.

Notwithstanding current heavy dependence on gas-fired electricity generation in the Eastern African Power Pool (EAPP), hydropower is expected to play an essential role in improving electricity access in the region. Expansion planning of electricity infrastructure is critical to support investment and maintaining balanced consumer electricity prices. Variations in water availability due to a changing climate could leave hydro infrastructure stranded or result in underutilization of available resources. In this study, we develop a framework consisting of long-term models for electricity supply and water systems management, to assess the vulnerability of potential expansion plans to the effects of climate change. We find that the most resilient EAPP rollout strategy corresponds to a plan optimised for a slightly wetter climate compared to historical trends. This study demonstrates that failing to climate-proof infrastructure investments can result in significant electricity price fluctuations in selected countries (Uganda & Tanzania) while others, such as Egypt, are less vulnerable.

The rail network in the US is the largest network within any single country at 140,000 miles of Class 1 tracks. The network is predominantly focused on freight traffic with the exception of key passenger corridors along the eastern seaboard and in the upper Midwest. This extensive rail network enhances connectivity, but also raises the question of potential vulnerability to climate changes over the next century. Specifically, projected changes in temperature highlight the vulnerability of tracks to temperature increases and the accompanying issue of track expansion, which under current operating policies can lead to train delays, and in the most extreme cases can lead to derailments. In this study, the issue of potential impacts to the rail network are analyzed in terms of the cost of potential increases in delays that will occur due to responses of train network operators to temperature increases. Impacts analyzed using a range of climate models indicate that the rail network may incur an increase in delay-minute costs over typical historic costs of between $25 and $45 billion cumulatively through 2100 under a low greenhouse gas emissions future, and between $35 and $60 billion under a high emission scenario. However, these costs could be reduced by up to an order of magnitude if current sensor technologies are incorporated into tracks, coupled with refinements to current speed reduction policies that better leverage temperature monitoring capabilities.

Wildfires are large sources of PM 2.5 in the United States. The size and frequency of wildfires in the western US have been increasing due to warmer temperatures, earlier spring snowmelt, and longer fire seasons, likely driven by climate change. The increasing trend of wildfire activities is expected to continue throughout the 21 st century and smoke could become the dominant source of PM 2.5 in the western US during the fire season. However, estimating future fire emissions and their impact on air quality is challenging.