Can the country do without nuclear power and natural gas? Sen. Bernie Sanders thinks so. But his position would set back the fight against global warming.

While campaigning in New York, Sanders has played up his opposition to nuclear power, and in particular the Indian Point power station 25 miles north of New York City, which provides a quarter of the city's electricity. The plant is a "catastrophe waiting to happen," he declared.

Sanders also has attacked fracking, the process of fracturing shale formations deep underground in order to extract natural gas. After years of contentious debate, New York's state government banned the technique, which drillers use widely in neighboring Pennsylvania.

As with nuclear power, Sanders was not just bowing to New York environmentalists; he had long insisted that the federal government should ban fracking across the country "if we are serious about safe and clean drinking water and clean air."

In fact, if we are serious about global warming, we will ignore Sanders' sloganeering.

When burned, natural gas produces about half of the carbon dioxide emissions of coal. The recent fracking boom contributed to a reduction in national carbon dioxide emissions over the past several years, as utilities switched from cheap coal to now-cheaper gas.

Sanders' rhetoric on nuclear power is even more concerning. Nuclear accounts for about a fifth of the country's electricity, and it is practically emissions-free. Shutting down that much clean electricity generation would put the country into a deep emissions hole.

Sanders argues that he will invest heavily in renewables. Yet every dollar spent to replace one carbon-free source with another is a dollar that could have been spent replacing dangerous and dirty coal plants.

Sanders is right that climate change demands an aggressive response, and he is right to favor a carbon tax. He should leave it at that: Put a price on carbon, insist on adequate regulation, and let the market find the fastest and most efficient road to slowing the warming of the planet.

FROM AN EDITORIAL IN THE WASHINGTON POST