density of each layer

concentration of ozone in each layer

temperature changes from variations in absorption of solar energy

concentration of oxygen in each layer

precipitation in each layer

Accumulation of carbon dioxide from volcanic eruptions

Drifting of the Antarctic Plate away from the South Pole

Formation of dust clouds due to meteorite impacts

Removal of carbon dioxide from the atmosphere

it is easy to transport.

it has a high net energy ratio.

it is pumped into pressurized tanks at deep sea oil rigs

the U.S. has more natural gas reserves than Russia.

it emits less carbon dioxide than other fossil fuels

Loss of fertile delta regions for agriculture

Change in global patterns of precipitation

Extinction of some species that have narrow temperature
requirements

Decreased rate of photosynthesis in vegetation

Increased frequency of hurricanes

Human feces

Ammonia

Phosphates

Nitrates

Heavy metals

Carbon dioxide, chlorofluorocarbons, hydrogen

Carbon dioxide, carbon monoxide, nitrogen

Carbon dioxide, methane, water vapor

Methane, nitrogen, nitrous oxide

thawing permafrost

the path of the Earth around the sun

volcanic eruptions

all of the above