APES 7.4 Atmospheric CO2 and Particulates

Enduring Understanding:

Human activities have physical, chemical, and biological consequences for the atmosphere.

Learning Objective:

Essential Knowledge:

CO2 appears naturally in the atmosphere from sources such as respiration, decomposition, and volcanic eruptions.
There are a variety of natural sources of particulate matter.

Anthropogenic vs. Natural Pollution Sources

Air pollution is any substance in the atmosphere that has harmful effects on people, ecosystems, or infrastructure and the economy
Sources can be anthropogenic or natural
- The primary focus of unit 7 is air pollutants from human activities and their effects
- This topic focuses on natural sources

Natural emissions are a major contributor to atmospheric CO2 levels, but natural processes are also sinks of carbon dioxide
The net effect of natural CO2 sources and sinks in minimal
- Natural sources typically emit carbon that was recently in the atmosphere anyway
- Burning fossil fuels for power, transportation, and petroleum products add excess carbon dioxide to the atmosphere
CO2 is a greenhouse gas necessary to support life and maintain global temperatures
- Excess CO2 that disrupts ecosystems, health, and the economy is a pollutant
If we breathe some CO2, it does nothing to us
- So it is not directly harmful to humans or animals
- It does, however, have detrimental effects when too much is in the atmosphere

PM is solid and liquid particles in the air that are small enough to be inhaled
Categorized based on the size in microns
Particulate matter under 10 microns is inhalable
- PM10 is between 2.5 and 10 microns in diameter
- These are associated with concerns about the eyes, nose, and throat
PM2.5 is under 2.5 microns in diameter
- Concerns about the inner functions of the lungs
There are also PM1 and PM0.1 that can enter the bloodstream