One of President Barack Obama's most controversial regulations is getting a lot of attention after President-elect Donald Trump nominated Oklahoma Attorney General Scott Pruitt to serve as administrator of the Environmental Protection Agency (EPA). The Clean Power Plan (CPP), under the purported authority of the Clean Air Act, requires states to develop plans to reduce emissions by 32 percent below 2005 levels. If a state fails to adopt a plan, the EPA creates one for it. The rule will supposedly avert 0.015°F by 2100 of future temperature increases.