Over the years, scientists have discovered the main function of the ozone layer. They found that the ozone layer naturally protects the Earth from ultraviolet radiation which in large quantities can be harmful. When organisms are exposed to large amounts of ultraviolet radiation, the exposure can lead to DNA mutations that can cause damage to the organism and even skin cancer in humans (NOAA News). Although stratospheric ozone absorbs most forms of ultraviolet radiation, about half of UV-a radiation gets through, and this radiation is the type that causes sunburn, skin cancer, and eye damage (Ozone Watch) . The graph below shows how most ultraviolet radiation is absorbed in the stratosphere, but about half of UV-a radiation manages to reach the Earth's surface (Ozone Watch). Over the last century, various human activities have reduced the effectiveness of the ozone layer. diminish. It has been shown that the release of chlorofluorocarbons from various daily activities causes a decrease in the thickness of the ozone layer especially above the poles (WUnder). Due to these reduced ozone levels, more harmful ultraviolet radiation has managed to reach the Earth's surface (Ozone Watch). With this increase in ultraviolet radiation reaching the Earth's surface in recent decades, scientists have noticed a dramatic increase in the number of cases of malignant skin cancer. In fact, scientists estimate that for every 1% decrease in ozone levels, there will be a 2-3% increase in the number of people suffering from certain skin cancers (Beyond Discovery). Another problem that emerged in the last century was the complex link between global warming and the ozone hole... middle of paper... Properties and behavior." General chemistry: atoms first / John E. McMurry, Cornell University , Robert C. Fay, Cornell University.. Second ed. Boston: Pearson, 2014. Print. "NOAA, NASA: Antarctic ozone hole second smallest in 20 years." years Np, nd Web. 20 November 2013. .Toon, Owen and Richard Turco Stratospheric clouds and ozone depletion." Scientific American June 1991: n. page Toon_Turco91_ozone. Web. November 20, 2013."What is ozone?." Ozone Hole Watch: Facts about ozone. Np, nd Web. November 20. 2013. .