The Sun is the source of energy for most of life on Earth. As a star, the Sun is heated to high temperatures by the conversion of nuclear binding energy due to the fusion of hydrogen in its core. This energy is ultimately transferred (released) into space mainly in the form of radiant (light) energy.
Mass and energy are closely related. Due to mass–energy equivalence, any object that has mass when stationary (called rest mass) also has an equivalent amount of energy whose form is called rest energy, and any additional energy (of any form) acquired by the object above that rest energy will increase the object's total mass just as it increases its total energy. For example, after heating an object, its increase in energy could be measured as a small increase in mass, with a sensitive enough scale.
The use of coal dates back to the Bronze Age, but it was the Industrial Revolution that led to its large-scale use, as the steam engine took over from the water wheel. Today world coal consumption is about 5.3 billion tonnes annually, of which about 75% is used to produce electricity. The region including the China and India uses about 1.7 billion tonnes annually, forecast to exceed 2.7 billion tonnes by 2025. The United States consumes about 1.0 billion tons annually. Almost one-third of all coal used was supplied by China in 2005.
Hansen is a vocal critic of the Bush Administration's ideology on climate change. In 2005 and 2006, he claimed that NASA administrators have tried to influence his public statements about the causes of climate change. He has also claimed that the White House edited climate-related press releases from federal agencies to make global warming seem less threatening, and that he is unable to speak 'freely', without the backlash of other government officials.
"Our decision about energy will test the character of the American people and the ability of the President and the Congress to govern this Nation. This difficult effort will be the 'moral equivalent of war', except that we will be uniting our efforts to build and not to destroy." – Jimmy Carter, 1977
"A great nation like the United States has a duty not to obstruct the fight against global warming but should, on the contrary, lead the combat, because what is at stake is the fate of all humanity." – Nicolas Sarkozy, 2007