Why was the formation of the ozone layer an important event in Earths history?
Approximately 0.6 to 0.8 billion years ago, oxygen levels in the atmosphere reached a level that enabled an ozone layer to form. Once the ozone layer was established, it protected living things in the ocean from hard UV radiation. As a result, living organisms moved out of the ocean and on to land. At that point, CO2 started to be absorbed by terrestrial plants, which put O2 directly back into the atmosphere. Thus, the evolution of the Earth’s atmosphere to form the ozone shield is important because it enabled life in the oceans to evolve to allow the expansion of plants and animals on land. http://www.esse.ou.edu/classes/geos2004/lectures/Lecture_17.htm http://irina.colorado.edu/lectures/Lec9.html 8.) Consider a world like Earth with a large tropical ocean and an atmosphere containing clouds. If you make a change (+/-) in the global mean temperature of the planet, all other things remaining the same, what change do you expect in the amount of area covered by clouds? How does this subs
