IN THE PAST two weeks, both President Obama and Republican challenger Mitt Romney claimed to possess farsighted plans for powering America’s economy. At their parties’ nominating conventions, the candidates and their surrogates described a future in which the country is more energy-independent, nearly everyone in the energy business succeeds and the energy-dependent economy hums along.

In fact, the visions articulated of late are far from farsighted. Neither adequately described the real and massive energy and environmental challenge America faces, let alone offered a credible strategy to face it.

The next president must manage a gradual transition off carbon-emitting technologies and toward lower-carbon options — while also recognizing that America does not have the luxury of wasting its wealth while reshaping its energy sector. Neither candidate’s plan is up to the task.

Mr. Romney would try to keep energy cheap. He deserves credit for opposing the renewal of a particularly inefficient wind-power subsidy, for example. But his latest energy independence plan doesn’t even mention the words “climate change,” and his full-throated endorsement of burning lots more coal is retrograde. Coal-related air pollution causes chronic illness and early death, and it is a primary culprit in global warming. On renewable sources of energy, Romney would and should invest in research, but he also treats emissions reduction as a nice byproduct of pursuing other goals, inspiring little confidence that he would reduce pollution enough.

At least Mr. Obama freely recognized the dangers of climate change last week, and he can claim some first-term accomplishments. Best are his groundbreaking fuel-efficiency standards for cars and trucks, which promise to curb oil use and emissions. Though the president can’t honestly take credit for the recent boom in natural-gas production, his administration has resisted environmentalist calls to crack down on obtaining this cheap fuel, which has about half the carbon intensity of coal. Wind and solar energy use has doubled but is still only a small part of the mix. The president has promoted energy research, and the Environmental Protection Agency under his watch has all but banned building traditional coal plants.

These accomplishments, however, resulted not from a well-designed plan but from a haphazard collection of half measures and lucky circumstances. Mr. Obama’s approach is both too expensive and too modest. It is too expensive because it includes an array of poorly designed subsidies and political payoffs — such as the wind tax credit Romney opposes. It is too modest because it attacks carbon emissions in a piecemeal fashion — sector by sector, even technology by technology — rather than by applying an ambitious common carbon plan across the whole economy.

Instead of “all of the above,” America needs a plan that blunts incentives to use dirty energy without overspending on government-backed boondoggles. The best way to do that is by putting a steadily rising price on carbon emissions, empowering consumers to decide how and where to wring carbon out of the economy. Though we suspect both candidates recognize the logic of this idea, neither wants to stand up for it this election season. That’s another waste.