Although the ozone layer is recovering over Antarctica following Montreal Protocol that banned chlorofluorocarbons (CFCs) that destroy ozone, newly published research indicates that it is declining over lower latitudes, the Guardian reported. The earth’s stratosphere ranges from 10km above ground to 50km. Ozone is gradually increasing in the upper stratosphere, heading towards levels that were observed prior to CFC-caused destruction, but is declining in the lower stratosphere, where there is most ozone. Ozone shields against the sun’s ultraviolet radiation that can cause cancer. “The study is in lower to mid latitudes, where the sunshine is more intense, so that is not a good signal for skin cancer,” Professor Joanna Haigh of Imperial College London, one of the researchers. Lower latitudes, especially the equator, are found over densely populated areas, home to several billion people. It is unknown what is causing this phenomenon, but one reason could be global warming, with air currents transporting more ozone to polar regions, leaving behind less at lower latitudes.