I think I know the ugliest word in the English language -- a neologism, actually, coined to describe the technique for pumping liquid at high pressure into rock to open up cracks so that natural gas will flow. It's called hydraulic fracturing, shortened by engineers to hydro-fracking and by everyone else to fracking.
And here's the thing: When first we heard of it, many of us environmentalists were very hopeful. Natural gas, you see, is cleaner than coal . When you burn it, you release about half as much carbon into the atmosphere. So, faced with the greatest problem the planet has ever faced -- global warming -- here was widespread hope that the new supplies of natural gas the technique might unlock would serve as a "bridge fuel" that would fill in for coal and let us take a little more time developing renewable energy. The gas companies were even more thrilled -- they calculated that there were trillions of cubic feet of gas underneath American soil, particularly in the Marcellus Shale, which stretches along the Appalachians.
But it didn't take long to figure out that fracking came with trouble attached . Stories spread of companies buying up drilling rights for a tiny fraction of what they were worth, and of big concrete drilling pads displacing field and forest up and down the interior East. And the millions of gallons of fluid that the drillers injected to fracture the deep rock? It was soon overwhelming sewage treatment plants, contaminating aquifers, wrecking rivers. Often it turns streams to brine. In West Virginia, for instance, a golden algae killed nearly every fish in one creek -- an algae that normally only shows up in ocean estuaries. Industry spread money to cash-strapped communities. Soon Pennsylvania was leasing its state forests, and even its state parks may not be safe. Opponents were outspent, but strong organizing continues. Groups such as Shaleshock and Catskill Mountainkeeper have managed to win temporary moratoriums on the practice in New York.
The more we've learned about fracking, though, the clearer it's become that its damage is not confined to the local area. When you fracture the rock to make the gas flow faster, most of it is captured by the pump at the surface. But some escapes (the documentary Gasland had a remarkable shot of homeowners lighting a gas fire by holding a match under their water tap). And unburned natural gas or methane (CH4 to you chemists) is an even stronger greenhouse gas than CO2. In other words, if more than 1 or 2 percent of the natural gas escapes straight into the atmosphere, this process would cause more global warming  than burning coal.
And that's what appears to be happening. The first real study of the subject -- by a team at Cornell University in New York -- showed that even in the best case fracking would provide only "marginal" improvement over coal and that at the moment it appears to be worse.
In other words, the bridge to the energy future is a rickety pier that just stretches out into the deep water and then stops. It's one more dodge, of the kind junkies specialize in, a way to keep from coming to terms with our addiction to fossil fuel. Forget the bridge -- we need to screw up our resolve and leap across the chasm to the real future of wind and sun. Not simple, not cheap, but not avoidable either.
In the meantime, we've got a new curse word.
Bill McKibben is the founder of 350.org , and author of Eaarth: Making a Life on a Tough New Planet  (Times Books, April 2010). This article first appeared in the July 2011 issue of  Sojourners magazine .