Russia holds the world's largest supply of natural gas. The country has 38% of proven reserves, more than 1,700 trillion cubic feet. Iran is in second place, with 812 trillion cubic feet.
Natural gas, a mixture of light hydrocarbons—mainly methane—and other compounds, is plentiful around the globe. It accounts for about 25% of the world's energy consumption—mainly for heating and generation of electricity—and is versatile. The use of natural gas offers various environmental benefits: natural gas is safer when transported, stored, and used; emissions of sulfur dioxide from natural gas are negligible; and emissions of nitrous oxide and carbon dioxide from natural gas are considerably lower than those from oil and coal. Increased dependence on natural gas could reduce the problems of acid rain and global warming.