(AP/JournalStar.com) -- In the same week that the Obama administration rolled out its mandate to impose the first-ever federal limits on greenhouse gas pollution from power plants, the AP reports that the Energy Department this week announced that America's carbon dioxide output from power plants hit a 27-year low in April.  A key factor for the lower carbon output is the switch to cleaner burning natural gas, the story notes, as well as gains in energy efficiency.

Read More