Human history can be told in terms of the history of energy. The discovery of fire, the domestication of animals, the discovery of fossil fuels, the electrification of cities, the oil wars in the Middle East, and advances in nuclear physics are all pivotal points in human history. Energy is a multifaceted concept; it is central to science and education, it plays pivotal role in economic growth, and it has a dominant position in international affairs. Conventional energy sources are major sources of environmental stress at global as well as local levels. Emissions from fossil fuels drive a range of global and regional environmental changes, including global climate change, acid deposition and urban smog. Coal mining disturbs vast areas of natural habitat, hydropower development can have significant environmental and social costs, and the exploration for and extraction of oil and natural gas can have significant impacts, particularly in sensitive ecosystems