Throughout history the majority of the human populations energy needs were met by traditional energy sources such as agriculture, human and animal labor, biomass, small amounts of coal, wind power, and water power.  When the Industrial Revolution came around things began to change.  Society developed new technology, and increasingly became more dependent on different energy sources that appeared cheaper and more efficient.  By the end of the 19^th century, electrical power became more and more used widespread.  Modern Civilization has now become overly dependent on electrical power.  Between 1971 and 1991, worldwide energy consumption has increased by approximately 45%.  Society is currently dependent on energy emitted the “big five” energy sources.  Currently, these energy sources can fully supply human needs.  Unfortunately, oil, coal, and natural gas (known as fossil fuels) are un-renewable resources ad someday they won’t be available to us anymore.  All five also cause great degradation to the environment and can be harmful to human civilization.  These “big five” energy sources are oil, coal, natural gas, hydroelectric, and nuclear power.