Why was the formation of the ozone layer an important event in Earths history?

One of the most important events in the Earths history was the formation of the ozone layer. The reason it was such an important event was because it enabled life to move out of the ocean and on to the land. The ozone layer protects life on earth from the harmful effects of UV radiation. UV radiation can damage or kill skin cells. (All of this information came from lecture 17) 8) 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 subsequently change the global mean temperature? What type of feedback is this?  more