By John Hanger

Bernie Sanders is airing a new television advertisement titled "Ban Fracking Everywhere," a siren song for the 51 percent of Americans who don't support shale-gas production.

But Sanders' fracking ban would paradoxically increase pollution and cause devastating utility bill increases for 400,000 Philadelphians with incomes near or below the poverty line.

As concerns about fracking mount, many believe the senator when he thunders that a ban is the right thing to do. In an ideal world, it would be, because gas drilling is an industrial process that cannot be done without causing some damage to the environment.

Yet as someone with a home in the Three Mile Island nuclear evacuation area and 32 years of energy policy experience, I sadly know that the real world of energy choices offers no perfect options but just unavoidable, uncomfortable tradeoffs.

In return for no fracking, the tradeoffs include higher prices paid by consumers, more coal burned to make electricity, loss of payments to landowners, and loss of jobs generated by the gas industry.

If fracking were banned everywhere, the supply of natural gas would plummet, and prices for at least gas and electricity would skyrocket, since 33 percent of America's power is generated from natural gas, even more than from coal, and since gas generation is also often the power-market price-setter. Many consumers would pay about $500 more each year on their power bills, while half of the nation's families, those who also use gas as a heating source, would pay about $1,000 more annually.

The Sanders fracking ban would be an act of unintended severe economic injustice by a candidate who has done so much to make economic inequality a major issue. Higher energy costs would be especially devastating for the poor, who often pay 20 percent or more of their limited incomes for energy, and would painfully pinch middle-income households. Even middle-income consumers who now cheer "Ban Fracking Everywhere" would jeer the skyrocketing energy bills when they arrived.

Apart from higher energy costs, a fracking ban would paradoxically put into the environment more soot, mercury, sulfur, nitrogen, and carbon. Why? If gas were made uncompetitive with coal, much dirtier coal-fired power plants would recover large chunks of the market share they have lost to cheap gas.

Indeed, the market share of coal-fired power plants has fallen from 49 percent in 2007 to 32 percent recently. As the nation switched to more gas, carbon emissions from power generation collapsed to levels last seen in 1990.

While Sanders' call to ban fracking is not intended to increase pollution or delight the coal industry, coal moguls would smile from ear to ear if fracking ended while coal mining and burning continued.

More coal mining and burning means more coal ash that requires disposal, and trouble lurks there, as experience in North Carolina and other states sadly proves. And it would mean more mining water to be handled and treated.

While gas drilling and fracking since 2008 have contaminated about 300 water wells with methane, including in Dimock, Pa., decades of coal mining have left Pennsylvania with 5,000 miles of streams destroyed by acidic water discharges from coal operations and three dozen underground coal fires. The environmental risks of coal greatly exceed those of gas.

In addition to more pollution, a fracking ban would inescapably cost jobs. Higher consumer energy costs, higher costs for feedstocks in the chemical and other industries, and a crippling of the natural-gas industry would destroy hundreds of thousands of jobs. Just in Pennsylvania, a drilling ban would eliminate half or more of approximately 72,000 jobs directly and indirectly created by shale-gas production - about 1 percent of the state's total jobs.

Instead of banning fracking now and reaping the nasty consequences of the unavoidable tradeoffs, we should strongly regulate, properly zone, and reasonably tax shale-gas development. The industry tragically opposes all these policies, but they would maximize benefits and minimize costs.

To be clear, drillers must be held accountable for damage done to families in places like Dimock and for the use of storage pits for wastewater, and underground disposal of drilling water must be prohibited.

Finally, America is at the start of a huge solar and wind boom that is taking place just as massive gas production has collapsed the price of gas. Renewables and energy efficiency, however, can and should be accelerated even more, and public investment in energy-storage research and commercialization should be greatly increased.

For the next 20 years, renewables and gas, in combination, will power America more cheaply and cleanly. By the end of that period, energy storage could be economical enough to allow renewables to work around the clock. At that point, a fracking ban may be possible, without today's nasty tradeoffs of more pollution, fewer jobs, and higher consumer bills.

John Hanger is a former secretary of the Pennsylvania Department of Environmental Protection.