Science - 2018-19

ES.11 a-c - The Atmosphere

The student will investigate and understand the origin and evolution of the atmosphere and the interrelationship of geologic processes, biologic processes, and human activities on its composition and dynamics. Key concepts include
a) scientific evidence for atmospheric composition changes over geologic time;
b) current theories related to the effects of early life on the chemical makeup of the atmosphere; and
c) atmospheric regulation mechanisms including the effects of density differences and energy transfer.

Bloom's Levels:  Analyze; Understand

Adopted: 2010


  • The atmosphere is a mixture of gases with suspended solids and liquids.
  • Weather is a short term pattern in atmospheric circulation patterns; climate is a long-term pattern.
  • The atmosphere exhibits change over time due to many causes, including human, biologic, and geologic events.

  • I can explain how plants can change the air I breathe.
  • I can determine what adaptations would be needed for humans to live on Mars.


  • The composition of Earth’s atmosphere has changed over geologic time. Earth’s atmosphere is unique in the solar system in that it contains substantial oxygen. 
  • The most primitive atmosphere was comprised of mainly helium and hydrogen. After the moon was formed, the early atmosphere contained mostly CO2, CO, and water vapor. This atmosphere was then modified by early photosynthetic life.
  • Early photosynthetic life such as cyanobacteria (blue-green algae) consumed carbon dioxide and generated oxygen. It was only after early photosynthetic life generated oxygen that animal life became possible. 
  • Earth’s atmosphere is 21 percent oxygen, 78 percent nitrogen, and 1 percent trace gases. The composition of the atmosphere can change due to human, biologic, and geologic activity. Human activities have increased the carbon dioxide content of the atmosphere. Man-made chemicals have decreased the ozone concentration in the upper atmosphere. Volcanic activity and meteorite impacts can inject large quantities of dust and gases into the atmosphere. 
  • The ability of Earth’s atmosphere to absorb and retain heat is affected by the presence of gases like water vapor and carbon dioxide. 


In order to meet this standard, it is expected that students will

a) analyze the evidence for atmospheric compositional change over geologic time including oxygen and carbon sinks and the role of photosynthetic organisms. 

c) analyze the array of climate feedback mechanisms that control the Earth’s temperature over time, and compare and contrast these feedback mechanisms to those operating on inner planets and the gas giants.


air pressure, albedo, atmosphere, chlorofluorocarbon, conduction, convection, Coriolis effect, exosphere, heat, ionosphere, land breeze, mesosphere, ozone layer, ozone, photosynthesis, radiation, sea breeze, stratosphere, thermosphere, trace gases, troposphere, ultraviolet rays, water vapor, wind

Updated: May 30, 2018