A line chart shows average carbon levels falling until about 2016, then rising again.
Measuring soot in the air at sites across the US
Black carbon pollution levels had been declining as vehicles, power plants and factories became cleaner. Since 2015, however, several bad wildfire years have pushed airborne black carbon levels up again. Data for 2023 is not yet available.
Annual soot concentration in micrograms per cubic meter averaged from 31 primarily rural locations.