A French cow in The Camargue. Doing what cows everywhere are known to do.
Methane is being emitted daily by cows and horses across this land, pigs too. Manure's another problem. But it could also be a solution. Right now the federal government is starting to lean toward cracking down on huge manure emitters, those factory farms where livestock are concentrated in tight space for more efficient feeding and eventual slaughter for the meat industry. Or to produce lots of eggs and milk. Here's what the Environmental Protection Administration is saying. I paraphrase: "Cut the crap."
Unlike cow-sourced methane, manure as a solution could be on more solid ground right now. Indeed, it's long been a dream of making money from manure, beyond selling it to weekend gardeners for their tomato patch. Here's a detailed fifteen-year old summary of the manure to methane dreams from one Midwestern ag school. They weren't too hopeful fore anything to happen quickly: "If energy and fertilizer shortages become more acute and pollution regulations concerning odor become more strict, methane generation may become a feasible process in waste management systems. Research is needed to reduce capital costs of methane generation systems and provide techniques for proper management of such systems."
In short, manure to methane to electricity or heat is happening, in small increments. But capturing all that free methane being emitted? Cowabunga. As far as I can tell, that awaits a new generation of greentech thinking.