Does air pollution—specifically particulate matter (aerosols)—affect global warming?
Air pollution occurs when the air contains gases, dust, fumes or odor in harmful amounts—aerosols are a subset of air pollution that refers to the tiny particles suspended everywhere in our atmosphere. These particles can be both solid and liquid and are collectively referred to as ‘atmospheric aerosol particles’ [1]. Most are produced by natural processes such as erupting volcanoes, and some are from human industrial and agricultural activities (see Figure 1). Those particles in the lowest layer of the atmosphere, where our weather occurs, usually stay relatively close to the source of emissions and remain in the atmosphere only a few days to a week before they fall to the ground or are rained out; those higher up in the atmosphere travel farther and may linger in the atmosphere for a few years. Light-colored aerosol particles can reflect incoming energy from the sun (heat) in cloud-free air and dark particles can absorb it. Aerosols can modify how much energy clouds reflect and they
