In early 1900 century about 80% population in the United States used to work in the agricultural farm and about 20% population used to work in the office and factories. By the end of 19th century 20% people worked in the farm and 80% people worked in the office and factories. Today scientists are arguing about human– changing .In this 20th century climate change is one of the important issue we are facing in the whole world. The change became more adverse after the introduction from farming nation to industrial nation where industries emitted their gases in the air. These emissions have caused almost 100% of the global warming in the Earth Today. Natural factors including solar activity, volcanic activity, causes change in solar energy output thus affecting the earths energy balance and climate. Global warming could be part of a natural cycle since carbon dioxide increases due to continuous burning of coal, oil and natural gases.