Historically Unattainable: Understanding Natural Variability in Ambient Air Quality Concentrations

Dr. Lacey and Dr. Kumar will discuss their recent evaluation of ambeint air quality in light of the new air quality guidellines recommened by the WHO. By using pre-industrial concentrations from the Coupled Model Intercomparison Project Phse 6 (CMIP6), they have estiamted that 78% of the global popualtion is outside of attainement for the 5 microgram per meter-cubed annual average guideline. THe analysis of present-day and future simulations follow the shared-socioeconomic pathways out to 2100 show that even with the most optimistic goals, this value persists to the end of the century and stays near present day values (above 955) under business as usual scenarios.