Air pollution refers to the release of pollutants into the air that are detrimental to human health and the planet as a whole.
Air pollutants have a complex relationship with climate change. Some pollutants, such as black carbon and ozone, increase warming by trapping heat in the atmosphere, while others, such as sulfur dioxide forming light reflecting particles, have a cooling effect on the climate.
Several studies suggest that, in addition to health benefits, reducing black carbon sources would lead to cooling of global temperatures (see: ‘Reducing black carbon emissions benefits both climate and health’). On the other hand, other studies point out that reducing air pollution could worsen climate change in the short-term by contributing to an increase in global temperatures (see: ‘Do climate policies need a ‘pollution safety margin’?’). This is still an area of active research with many uncertainties to resolve.
Here are the most common types of air pollution:
Smog and soot
These two are the most prevalent types of air pollution. Smog, or “ground-level ozone,” as it is more wonkily called, occurs when emissions from combusting fossil fuels react with sunlight. Soot, or “particulate matter,” is made up of tiny particles of chemicals, soil, smoke, dust, or allergens, in the form of gas or solids, that are carried in the air.
Hazardous air pollutants
These are either deadly or have severe health risks even in small amounts. Almost 200 are regulated by law; some of the most common are mercury, lead, dioxins, and benzene.
Greenhouse gases
By trapping the earth’s heat in the atmosphere, greenhouse gases lead to warmer temperatures and all the hallmarks of climate change: rising sea levels, more extreme weather, heat-related deaths, and increasing transmission of infectious diseases.
Pollen and mold
Mold and allergens from trees, weeds, and grass are also carried in the air, are exacerbated by climate change, and can be hazardous to health.