bigstockphoto

Mainstream environmental groups have struggled to find the right line on shale natural gas and the hydraulic fracturing or fracking process. Gas has a much smaller carbon footprint than coal—according to most scientists—and produces far fewer air pollutants. That was enough for many major green groups to give support to gas as a “bridge fuel” to a cleaner energy future—the next best domestic alternative to coal as an electricity source while alternatives like wind and solar scaled up. ....