You know that if you’re out in the sun a lot, you need to put on sunscreen. The UV (ultraviolet) light from the sun can cause sunburn, and even skin cancer. Luckily, the Earth has a big layer of natural “sunscreen” in the form of the ozone layer. This is like a blanket of oxygen gas and ozone gas that blocks out most of the dangerous rays from the sun. However, since the 1970s, there are areas, especially over Antarctica, where the ozone layer is getting thin, and more UV is getting through.
Scientists have worked out that the main cause of the hole in the ozone is chlorofluorocarbons (CFCs). Many types of sprays, refrigeration units, air-conditioners and Styrofoam use CFCs. This gas can rise up as far as the ozone layer and cause the ozone molecules to break down. Many countries have signed a treaty promising to cut back on use of CFCs.