Earth hour is something like friendly with the environment.It is held on 28 March 2009.People are organising this event because they want to save the earth and some endangered animals also.If everyone doing earth hour the earth will be save.We can do by encouraging others and we can tell them what is the benefit of earth hour.The other problems that earth facing is AIR POLLUTION,WATER POLLUTION and ENERGY DEPLETION.We can solve AIR POLLUTION by using less vehicles such as motorbike and cars.