Frequently Asked Questions: (8) Local vs Global Pollution Nexus

While health effects drive most of the PM pollution concern, PM also affects regional and global atmospheric chemistry and the radiation balance. Aerosol particles scatter and absorb solar radiation, and also alter the formation of cloud droplets. These physical interactions change the earth’s radiation balance, affecting local and global temperatures and possibly precipitation.

The Aerosols (PM) and ozone that are usually considered only in the air quality domain, also affect climate change. The understanding of the impact of aerosols on the climate system and how to evaluate this impact for policy relevant issues is very low. Research continues to assess the effects of many different types of aerosols on climate under different conditions.

Also see a review - Black Carbon to the Rescue.

PM pollution can also impact visibility in urban centers. Mountains or buildings once inplain sight can suddenly be blocked from view. Air pollution that reduces visibility is often called haze or smog.

The term smog originally meant a mixture of smoke and fog in the air, but today it refers to any visible mixture of air pollution. The incidents of haze and smog in cities are increasing, which typically starts in cities and travels with the wind to appear in the more remote areas.

One consequence of smog over any given area is that it can change the area’s climate. Certain dark particles, such as carbon, absorb solar radiation and scatter sunlight, helping produce the characteristic haze that is filling the skies over the world’s megacities and reducing visibility.

See other FAQ's.