The correct answer is D. ultraviolet radiation.
The ozone layer is a region of Earth’s stratosphere that absorbs most of the Sun’s ultraviolet radiation. It contains high concentrations of ozone (O3) relative to other parts of the atmosphere, although still small in relation to other gases in the stratosphere. The ozone layer contains less than 10 parts per million of ozone, while the average ozone concentration in Earth’s atmosphere as a whole is about 0.3 parts per million. The ozone layer is mainly found in the lower portion of the stratosphere, from approximately 20 to 30 kilometers (12 to 19 mi) above Earth, although its thickness varies seasonally and geographically.
The ozone layer is important because it protects life on Earth from harmful ultraviolet radiation. Ultraviolet radiation can cause skin cancer, cataracts, and other health problems. It can also damage plants and animals. The ozone layer absorbs most of the Sun’s ultraviolet radiation, preventing it from reaching Earth’s surface.
The ozone layer is being depleted by human activities, such as the use of chlorofluorocarbons (CFCs). CFCs are chemicals that were once widely used in refrigerators, air conditioners, and other products. When CFCs reach the stratosphere, they break down and release chlorine atoms. These chlorine atoms react with ozone molecules, destroying them.
The depletion of the ozone layer is a serious problem. It is estimated that the ozone layer has thinned by about 10% since the 1970s. This thinning has allowed more ultraviolet radiation to reach Earth’s surface, increasing the risk of skin cancer and other health problems.
There are a number of things that can be done to protect the ozone layer. One important step is to reduce the use of CFCs and other ozone-depleting substances. Other steps include using energy-efficient appliances and products, and recycling.
By taking these steps, we can help to protect the ozone layer and reduce the risk of skin cancer and other health problems.