Certain gases, labeled greenhouse gases, can trap solar radiation from reflecting off into space. As illustrated in the diagram below, solar radiation enters the atmosphere, and bounces off of clouds and the earth's surface back toward space. It is then reflected back again by greenhouse gases in the atmosphere, which then return the radiation as heat back to the earth's surface.
This means that more radiation is trapped in the lower atmosphere of the earth instead of being let back into space. The increasing greenhouse effect from greenhouse gases is leading to an acceleration of global climate change.
There is a naturally-occurring layer in our atmosphere called the ozone layer. It protects the earth from receiving too much solar radiation.
However, air pollutants like chlorofluorocarbons (CFCs) can react with ozone and deplete the amount available in the upper atmosphere. The result is an increased amount of radiation reaching the earth's surface.
Smog is created when ground-level ozone combines with pollutants such as sulfur oxide, nitrogen oxide, volatile organic compounds, and other elements. Smog is usually the result of vehicle fumes, sunlight, and moisture.
It can cause respiratory infections and damage, as well as harm the body's organs, tissues, and cardiovascular systems. Other health problems such as emphysema, asthma, and bronchitis can also result.
Acid rain results when pollutants, such as sulfur and nitrogen oxides, mix with water in the air and then precipitate (see diagram below). Because air pollution can disperse and travel long distances through the air, impacts can result far from the source. Ecosystems near and far can experience acidified soils and damaged root systems from air pollution, and this can prevent them from absorbing nutrients or providing stability in a storm.
Acid rain damages forests, creating uneven and sparse foliage, which reduces photosynthesis efficiency. Water systems -- most commonly lakes -- can become acidified, and this negatively impacts ecosystems and even kills species.
Pollutants that don't mix with water when they are airborne, such as those released by the coal plant pictured below, will eventually be deposited on land or in water systems.
The impacts of particulate matter on human and ecosystem health can be damaging. Particulates can lead to damaged respiratory systems, as well as infections. In addition, they can negatively impact cardiovascular systems, organs, and tissues. Illnesses like emphysema, asthma, and bronchitis can also result.