This week, President Obama's special adviser John Podesta dropped a few classic Washington bromides about those unreasonable environmentalists:

"If you oppose all fossil fuels and you want to turn that switch off tomorrow, that is a completely impractical way of moving toward a clean-energy future," Podesta told reporters during a roundtable discussion at the White House.

"With all due respect to my friends in the environmental community, if they expect us to turn off the lights and go home, that's sort of an impractical suggestion," he added. [Politico]

This is a fairly typical example of Washington's brand of hard-headed, realistic thinking. Of course it's impractical to suggest that we should go full renewable energy, right now — so impractical that no one is seriously suggesting that. However, it's also true that absent extremely aggressive emissions reductions very soon, it's scientifically unlikely that our society and the biosphere will survive intact into the far future. How's that for hard-headed realism?

In any case, those remarks are mainly a distraction. Much more worrisome ones come a bit further down, where Podesta comments on U.S. natural gas export policy. The crisis in Ukraine has created an opening for North American natural gas, with policymakers eager to chip away at Russia's dominance in Europe's natural gas market. In addition, Europe offers American producers better prices and an opportunity to clear some of the gas out of the glutted U.S. market.

Podesta's comments come one day after the Sierra Club, Friends of the Earth,, and a slew other green groups called on President Barack Obama to reject calls to speed up permits to export U.S. liquefied natural gas, arguing that the policy would violate the administration's pledge to tackle climate change.

Asked about the criticism, Podesta spoke generally, saying the country would benefit if more power plants relied on gas... He shrugged off the call for Obama to step back from LNG exports, saying that the Energy Department was in charge of reviewing the export applications. [Politico]

Obama's climate legacy is mainly about reducing our reliance on coal, which makes natural gas useful because it is outcompeting coal. It would be much better if the massive methane leaks that stem from fracking could be contained, but for the moment natural gas is doing an environmental service.

The great danger of upping exports to Europe, as Henry Farrell pointed out, is that it will entrench the fracking boom and huge new export terminals under the aegis of national security, which could be nearly impossible to dislodge.

Remember, after coal is dead, natural gas has to die soon afterward. Most extant carbon reserves must be left in the ground if catastrophic climate change is to be avoided.

Furthermore, increased natural gas prices have already strengthened the position of the coal industry, allowing it to recapture some of its electricity market share. With big-time exporting, that trend will only be increased. If coal regains market strength, it will regain political strength, both through lobbying money and, more importantly, thousands of coal-mining jobs. All of which threatens the Obama administration's top environmental goal: strong EPA rules against carbon pollution on existing coal-fired plants. Such rules would have a better chance of making it through the bureaucratic gauntlet if coal is kept on the back foot.

If Obama approves those natural gas exports, he could end up sacrificing his entire climate legacy.