Why was the formation of the ozone layer important for life to spread from oceans onto land?

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ozone depletion — Ozone depletion The Antarctic ozone hole reaches its maximum extent in October of each year. On October 7, 2021, when this image was captured, the Antarctic ozone hole spanned 24.8 million square km (9.6 million square miles).

The formation of the ozone layer was essential for the expansion of life from the oceans onto land because it provided a critical shield against the Sun’s harmful ultraviolet radiation.21

Approximately two billion years ago, rising oxygen levels—produced by marine organisms—allowed ozone to accumulate in the upper atmosphere, gradually forming the stratosphere. Before this protective barrier existed, the intensity of solar radiation reaching the surface was lethal to most living things. By effectively screening out high levels of UVB radiation, the ozone layer created a safer environment that facilitated the migration and survival of plants and animals on land.21