There are over 400,000 fracked wells in the USA at the moment - rising rapidly. Stanford University estimate that EPA reports have underestimated frack site related methane leaks by up to 50%!
Methane has a far great climate warming effect than CO2 ( the other major contributor being the billions of livestock now reared on the planet ). Think flooding? As a minimum. We ain't seen nothing yet.
Read the report + short video here: http://www.youtube.com/watch?v=7kBCMEUuSNw