Air pollution affects many parts of the global ecosystem

The term ecosystem highlights the fact that both living and non-living parts of the environment, including humans, are all part of a highly interconnected and interdependent system of life. Ecosystems and the organisms within are not static: they are continually changing and adapting to new environmental conditions and relationships. The survival of any species depends on its ability to adapt to these changes.

But pollutants disrupt the balance and energy flow of the ecosystem. They can poison organisms and cause rapid and harmful changes in the environment. These changes may stress certain species, making them more vulnerable to disease and seasonal conditions like drought and cold, and may reduce their ability to respond and survive. The impact of air pollution may also be felt differentially by each species or individual within a species. Species' young, sick, older and rapidly growing members all tend to be more vulnerable to the effects of pollution.

Importantly, the loss of any species can have a significant impact on the ecosystem by disrupting the complex relationships among all members of the food chain. A species' survival depends on the existence of these relationships, between the plants capturing the sun's energy and the organisms who feed on these plants and each other. There may be a loss in biodiversity and a bias towards fewer species that are more suitable to the changing conditions. Air pollution may shift an ecosystem to become dramatically different than the one we are familiar with or dependent on. The eventual impact of these changes throughout the ecosystem remains uncertain, but of great concern.