I remember back in the 1970's, (the "real" gas shortage crisis?) someone actually devised and built a car that ran on chicken manure.
At least methane has much greater potential for providing real energy than a proposition that is merely 'hot air'.
Today there is neither any shortage of gas, nor any shortage of hot air: "blah, blah, blah". Gee, even animal emissions have more potential value than what emanates from our mouths.