Modeling Fallout from Trinity to Nuclear War

The July 16, 1945 Trinity nuclear weapon test marked the first large-scale, uncontrolled release of radioactive materials into the atmosphere, contaminating land and exposing downwind populations to radiation. Over the following decades, more than five hundred atmospheric nuclear tests were conducted worldwide to advance nuclear weapons development, dispersing radioactive fallout at local, regional, and global scales, and increasing the risks of radiation-induced health effects for affected populations.



This presentation explores how modern scientific tools—combining advanced atmospheric transport models, reanalyzed historical weather data, and detailed nuclear weapon explosion source terms—enable a comprehensive reassessment of the radiological impacts of past nuclear testing. These analyses provide critical insights for shaping compensation and remediation policies while also identifying exposed populations in regions where historical fallout data is sparse or unavailable.



Furthermore, the presentation demonstrates the scalability of these tools for modeling fallout from modern nuclear conflict scenarios. By producing hour-by-hour fallout projections at kilometer-scale resolution anywhere on Earth, and integrating global population distribution, three-dimensional urban building data, and ecological and agricultural datasets, it is now possible to conduct detailed assessments of nuclear war’s physical and societal consequences. These include impacts on public health, socioeconomic systems, agriculture, and the environment at local, regional, and global scales.