Man-made air pollution is also changing the Earth's atmosphere so that it lets in more harmful radiation from the Sun. Although we have now banned products which can harm the Earth's ozone layer, ozone holes over Antarctica and the Arctic still form every year. At the same time, mankind is releasing more greenhouse gases to the atmosphere, preventing heat from escaping back into space and leading to a rise in global average temperatures. Global warming will raise sea levels and change climates all over the world. Some places will become hotter and drier, others wetter. The incidence of severe storms and flooding is likely to increase. Global warming will also affect food supply and increase the spread of tropical disease.