“Natural Gas May Be Easier On Climate Than Coal, Despite Methane Leaks” (NPR) http://www.npr.org/2013/09/16/223122924/despite-leaks-during-production- natural-gas-still-better-than-coal
“Coal vs. Natural Gas: It’s Complicated” (Houston Chronicle) http://www.chron.com/business/energy/article/Coal-vs-natural-gas-It-s- complicated-3897251.php
“Coal vs. Natural Gas Power Plants, with Lincoln Pratson” (Duke University Energy Initiative) http://www.youtube.com/watch?v=ZzUcn01-KIg
“Shale Gas vs. Coal” (Steffen Jenner and Alberto Lamadrid) http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2025627
“Is Natural Gas ‘Clean’?” (New York Times) http://opinionator.blogs.nytimes.com/2013/09/24/is-natural-gas-clean/?_r=0
“Coal vs. Natural Gas Quiz” (National Geographic) http://science.nationalgeographic.com/science/coal-vs-natural-gas-quiz/