Decarbonization and recarbonization: world coal is making a comeback

Many of us have heard the buzz about the "decarbonization" strategy, where the world first substitutes gas for coal since gas has less carbon and more hydrogen. Then later we substitute hydrogen or electricity for gas, and voila no more carbon problem. With the discussion of the vast new U.S. shale gas reserves, that may be the talk domestically, but at the world level, a different trend is underway: "recarbonization." Coal, which was 23% of the world's primary energy supply in 2000, has jumped to 28%, while petroleum fell from 37% to 33% over the same period -- gas was unchanged at 23% -- according to the US Energy Information Administration. So, the world as a whole is moving in the opposite direction. The effects are already showing up in CO2 emissions. According to the Carbon Dioxide Information and Analysis Center (CDIAC) at Oak Ridge National Labs, petroleum had been the leading source of CO2 for years, but in 2005 coal surpassed petroleum to become the biggest source among coal, oil, and gas. This trend is unlikely to change any time soon: economic growth in China and India is massive, and coal is the fossil fuel to which these countries have easiest access.