arXiv subjects

Alan Robock

Publications and source records attributed to Alan Robock.

3 recordsLinked to original sources

arXiv2026

Impacts of Nuclear War on Human Health from Changed Surface Ultraviolet Radiation

Climate model simulations indicate that surface ultraviolet (UV) radiation would change after soot injection into the stratosphere during a nuclear war, due to the competing effects of ozone depletion and aerosol attenuation. Using climate model simulations, we evaluate UV impacts under two scenarios: a regional India-Pakistan conflict producing 5 Tg of soot and a global U.S.-Russia war producing 150 Tg. UV enhancements due to ozone depletion substantially shorten safe outdoor exposure time, particularly for individuals with lighter skin types. Applying UV dose-response relationships to the year 2000 population data, without accounting for direct conflict mortality or famine-related population loss, the 5 Tg scenarios result in approximately 5,300-9,800 additional skin cancer deaths within 10-15 years and up to 75,000 cumulative excess deaths over the following century. In contrast, strong aerosol attenuation under the 150 Tg scenario initially suppresses surface UV, resulting in about 8,500 fewer skin cancer deaths within 15 years and a maximum cumulative reduction of approximately 17,000 deaths over the following century. These findings demonstrate that nuclear war-induced changes in surface UV radiation represent a persistent but previously understudied health impact of nuclear war. While skin cancer would not dominate overall mortality following a nuclear war, enhanced cumulative surface UV radiation represents an additional, long-lasting threat to human health that compounds other global impacts such as climate disruption and food insecurity. The excess UV may also pose negative impacts on animals and plants, including those used for agriculture, which remain to be quantified.

physics.ao-ph↗

arXiv2026

Impacts of Sulfate Injection Geoengineering on Particulate Matter with Diameter less than 2.5 {\mu}m

Particulate matter with aerodynamic diameter less than 2.5 {\mu}m (PM2.5) is of great concern for human health. Here, for the first time, we examine the impact of sulfate aerosol geoengineering on PM2.5, using the output from the Geoengineering Large Ensemble (GLENS) project. GLENS is an ensemble of climate model simulations injecting SO2 into the stratosphere to balance RCP8.5 forcing using the Community Earth System Model, version 1. GLENS geoengineering reduces global averaged surface PM2.5 mass concentrations compared with RCP8.5 and also changes PM2.5 composition with more percentages of organic carbon and sulfate. The total reduction of PM2.5 is a result of less dust and sea salt concentrations. Dust emission is declined under GLENS geoengineering because of increased soil moisture and leaf area index over desert regions, and less emission of sea salt is due to slower wind speeds when geoengineering is applied. Excluding dust and sea salt, there is more global averaged PM2.5 under GLENS geoengineering relative to RCP8.5, predominantly due to more aerosol phase secondary organic aerosol (SOA). Since gas precursors of SOA are prescribed in the simulations, a cooler environment with geoengineering tends to transfer more gas phase SOA to aerosol phase. Changes in PM2.5 concentration and composition with applied geoengineering may have potential human health impact. Another new finding of this study is that the large amount of injected SO2 does not increase surface sulfate aerosol as a component of PM2.5, as the majority of sulfate aerosol reaching the boundary layer is in the coarse mode, which represents a very small fraction of the PM2.5. But the difference of deposition spatial distribution between geoengineering and RCP8.5 may have potential impacts on ecosystem.

physics.ao-ph↗

arXiv2025

COMBUST: Gridded combustible mass estimates of the built environment in the conterminous United States (1975-2020)

The increasing occurrence of natural hazards such as wildfires and drought, along with urban expansion and land consumption, causes increasing levels of fire risk to populations and human settlements. Moreover, increasing geopolitical instability in many regions of the world requires evaluation of scenarios related to potential hazards caused by military operations. Quantitative knowledge on burnable fuels and their spatio-temporal distribution across landscapes is crucial for risk and potential damage assessments. While there is good understanding of the distributions of biomass fuels based on remote sensing observations, the combustible mass of the built environment has rarely been quantified in a spatially explicit manner. Therefore, we developed fine-grained estimates of urban fuels for the conterminous United States, estimating the combustible mass of building materials, building contents, and personal vehicles at 250 m spatial resolution. The resulting dataset is called COMBUST (Combustible mass of the built environment in the conterminous United States) and includes different backcasting scenarios from 1975 to 2020. COMBUST is based on the integration of a variety of geospatial data sources such as Earth-observation derived data, real estate data, statistical estimates and volunteered geographic information. COMBUST is accompanied by COMBUST PLUS, a set of consistently enumerated gridded datasets facilitating combustion exposure modelling of buildings and population. These datasets constitute a rich resource for ecological and social science applications, as well as for disaster risk management and planning-related decision making for U.S. settlements. COMBUST is available at https://doi.org/10.5281/zenodo.15611963.

physics.soc-ph↗