Why Carbon Is So Hard to Regulate.

The article discusses the efforts of U.S. President Barack Obama to implement a climate change policy in his second term. Under the terms of the 1990 Clean Air Act Amendments, the U.S. Environmental Protection Agency (EPA) should regulate harmful pollutants that endanger human health. It designated carbon dioxide as a harmful pollutant in 2009. The law compels Obama to regulate carbon but fails to state how to do it.