The Sun
The sun is the source of all life on Earth. It ultimately provides all the daily energy to fuel the cycle of life that goes on around us. Without the Sun, life on this planet would cease to exist.
The earth's atmosphere, particularly the ozone layer, shields us from most of the shorter, more harmful wavelengths while allowing essential longer wavelength ultraviolet, visible and infrared light to penetrate.
Scientists tell us that the ozone layer is being seriously depleted by pollutants, Experts agree that this will allow more of the potentially damaging, short-wave UV light to reach us, so we must be more careful than ever before to avoid excessive exposure to natural sunlight.