Memorandum of June 25, 2013: Power Sector Carbon Pollution Standards, Memorandum for the Administrator of the Environmental Protection Agency [open pdf - 313KB]
"With every passing day, the urgency of addressing climate change intensifies. I made clear in my State of the Union address that my Administration is committed to reducing carbon pollution that causes climate change, preparing our communities for the consequences of climate change, and speeding the transition to more sustainable sources of energy. [...] The United States now has the opportunity to address carbon pollution from the power sector, which produces nearly 40 percent of such pollution. As a country, we can continue our progress in reducing power plant pollution, thereby improving public health and protecting the environment, while supplying the reliable, affordable power needed for economic growth and advancing cleaner energy technologies, such as efficient natural gas, nuclear power, renewables such as wind and solar energy, and clean coal technology. [...] This memorandum shall be implemented consistent with applicable law, including international trade obligations, and subject to the availability of appropriations."
Federal Register: http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR
Federal Register /Vol. 78, No. 126 /Tuesday, June 25, 2013 / Presidential Documents 39535-39537