HEATHER RODGERS and SAMANTHA COOK – Environmental groups have long warned that America’s ravenous consumption of fossil fuels is not sustainable as a matter of public health or econmic health — either on a national or planetary level. But on the heels of a boom in domestic natural gas production — most of it the result of the adoption of hydraulic fracturing, or fracking — their opponents are in the ascendency. The conservation and convert-to-clean-fuels messages of the environmentalists are increasingly deridedas out of touch, unrealistic, and harmful to the economy.