Leveraging the Scientific Literature for Projecting the Impacts of Climate Change on Wildfire Smoke Toxicity: Science Synthesis and Assessment in Support of Public Health Adaptation Planning

Wildfire smoke comprises a highly variable mix of reactive gases and chemically complex particles – a mixture that changes in composition as it is transported through the atmosphere.  An on-going, global scientific effort begun more than 30 years ago to characterize wildfire smoke chemical composition under various conditions has built a rich and continually growing literature.  Climate change is altering the physical, biological, and photochemical variables may affect the toxicity of smoke by altering the chemical composition of the gases and particles produced by wildfire.   These include: ecosystems/fuel species composition, form and moisture status; fire weather patterns; dominant burning processes (e.g., high temperature combustion versus low temperature pyrolysis); atmospheric transport and photochemical reaction conditions; the concentrations of smoke-entrained soil and ambient dust; the concentration and viability of soil pathogens lofted by fire convection and borne on ambient dust; and the atmospheric mixing processes that bring humans into contact with smoke. Given the complex role that climate change processes can play in determining smoke composition, synthesis and integration of established science across the relevant disciplines into our analytical structure is necessary to reduce uncertainty in our understanding of the current and long-term health impacts of wildfire smoke.  A strategic, on-going synthesis of the relevant literature impacting smoke emissions and chemistry can help narrow these scientific uncertainties and assist public health planners in better understanding the potentially changing composition of smoke as climate change proceeds.    Leveraging the tremendous volume of potentially relevant, published science across the many relevant scientific disciplines calls for literature search and synthesis strategies targeted towards the generation of practical insight into effective future adaptation approaches.  The conceptual framework developed for this project, comprising a set of targeted questions associated with each earth system component playing a role in smoke chemistry, will be presented.

Impact/Purpose

The composition of wildfire smoke and its human respiratory toxicity is a function of a number of variables, including the composition of the burning ecosystems, the vulnerability to burning of the available fuels, burning conditions, the presence of bioaerosols and entrained soil and dust, and the meteorological conditions to which the primary smoke is subject (affecting transport and smoke photochemistry). Some of the more sensitive variables (i.e., ecosystems composition, burning conditions, atmospheric transport patterns and photochemistry) are subject to climate warming-induced change. The project that is the subject of this presentation is endeavouring to synthesize the existing scientific literature in an effort to map what is understood about the interconnecting biological, physical and chemical processes that can be expected, on the basis of current climate projections, to change and what the toxicological consequences will be for smoke and the people who will be exposed to it.  The presentation will touch on the insights that have been generated by this synthesis effort, to date, and present next steps in the effort.  The importance of the work lies in the potential of achieving early foresight into what Earth’s atmospheric environment will resemble and what may be needed to protect human health in the coming decades. Target communities: The ultimate objective of this work is to support the public health community and its efforts to prepare for climate change-induced health impacts.  Scientist engaged in relevant work from all relevant specialties will have an interest, as well as regional air quality experts.

Citation

Hemming, Brooke L., A. Barkley, U. Shankar, H. Pye, J. Markwiese, P. Byrley, T. Minich, J. Reichman, AND T. Dean. Leveraging the Scientific Literature for Projecting the Impacts of Climate Change on Wildfire Smoke Toxicity: Science Synthesis and Assessment in Support of Public Health Adaptation Planning. American Geophysical Union Fall Meeting 2024, Washington, DC, December 09 - 13, 2024.