brenda shafer is an energy expert at the us naval postgraduate school. so for all the, you know, sort of so called environmental activists. the thought they had a big win here. they're actually bringing to higher demand for coal and fuel oil. but some experts say elegy brings its own baggage. 80 percent of natural gas in the us comes from fracking. a process that relies on force and chemicals under ground. using high pressure, fracking has been linked to contaminated groundwater. increase these make activity and the release of methane a potent greenhouse gas it's more than a 100 times more powerful than carbon dioxide through the time it's in the atmosphere. robert howard is an earth system scientist and professor at cornell university. my research suggests that at least a 3rd of that, maybe half of that total global increase is methane emissions from frac shield gas in the united states. one of howard's recent studies asserts that natural gas might actually be dirtier than cold. consider all the energy it takes to drill wells, practice shell, rock lique