China Overtakes U.S. As Leading CO2 Polluter

China has officially overtaken the United States as the world's largest emitter of carbon dioxide, the leading greenhouse gas causing global warming, at least according to one estimate. While China's growing influence in this area was not unexpected, the rapidly developing country's emissions weren't expected to exceed America's for at least a year. An analysis by the Netherlands Environmental Assessment Agency, however, show China's emissions have already exceeded that of the U.S. The revelation will only heighten the debate about climate action. Internationally, one of the key questions has been whether countries like the United States and European nations that have been major polluters for a century or more face a greater burden to reduce emissions than developing nation's like China and India. While their contributions to the problem were historically relatively low, they now contribute greatly. For more on this story, click here.