Standard 5: Students will understand that Earth's atmosphere interacts with and is altered by the lithosphere, hydrosphere, and biosphere.

Objective 1: Describe how matter in the atmosphere cycles through other Earth systems.
a. Trace movement of a carbon atom from the atmosphere through a plant, animal, and decomposer, and back into the atmosphere.
b. Diagram the nitrogen cycle and provide examples of human actions that affect this cycle (e.g., fertilizers, crop rotation, fossil fuel combustion).
c. Interpret evidence suggesting that humans are influencing the carbon cycle.
d. Research ways the biosphere, hydrosphere, and lithosphere interact with the atmosphere (e.g., volcanic eruptions putting ash and gases into the atmosphere, hurricanes, changes in vegetation).

Objective 2: Trace ways in which the atmosphere has been altered by living systems and has
itself strongly affected living systems over the course of Earth’s history.
a. Define ozone and compare its effects in the lower and upper atmosphere.
b. Describe the role of living organisms in producing the ozone layer and how the ozone layer affected the development of life on Earth.
c. Compare the rate at which CO2 is put into the atmosphere to the rate at which it is removed through the carbon cycle.
d. Analyze data relating to the concentration of atmospheric CO2 over the past 100 years.
e. Research, evaluate, and report on international efforts to protect the atmosphere.