The Evolution of the Atmosphere

Question	Answer
Describe the first phase of the earth's atmospheric development	Volcanoes gave out gases and erupted constantly so it was impossible for an atmosphere to form. However, the earth started to cool so a thin atmosphere of CO2 (with small amounts of water vapor) could form. Oceans were later formed from this cooling too
How were oceans formed?	The condensation of the water vapor in the phase 1 atmosphere
Describe the second phase of the earth's atmospheric development	The Co2 atmosphere encouraged algae and green plants to grow, which lead to a declining level of CO2 and outputting of O2 from photosynthesis. However, the plants died and were buried under sediment, along with some evolved skeletons of marine life. This produced fossil fuels
Describe the final stage of the earths atmospheric development	The build up of oxygen killed some lifeforms that couldn't tolerate it, but allowed other complex organisms to flourish. The Oxygen also created the ozone layer, which blocked out most of the sun and enabled even more complex life to develop

Resource summary

	Created by Adam Collinge almost 10 years ago