On a sweltering day in Washington, D.C., President Barack Obama sweated as he laid out his new plan to combat climate change. In addition to the mandatory cuts in CO2 pollution from coal-fired power plants and the efforts to protect the country from the ravages of climate change highlighted by my colleague Mark Fischetti, Obama also found time to mention a little pipeline that would connect the tar sands in Alberta, Canada with refineries along the Gulf Coast in Texas. To wit:

"I put forward in the past an all-of-the-above energy strategy, but our energy strategy must be about more than just producing more oil. And, by the way, it's certainly got to be about more than just building one pipeline.

Now, I know there's been, for example, a lot of controversy surrounding the proposal to build a pipeline, the Keystone pipeline, that would carry oil from Canadian tar sands down to refineries in the Gulf. And the State Department is going through the final stages of evaluating the proposal. That's how it's always been done. But I do want to be clear: Allowing the Keystone pipeline to be built requires a finding that doing so would be in our nation's interest. And our national interest will be served only if this project does not significantly exacerbate the problem of carbon pollution. The net effects of the pipeline's impact on our climate will be absolutely critical to determining whether this project is allowed to go forward. It's relevant."

Indeed. Here's the full speech.

You can imagine how much effort journalists, policy wonks and environmentalists have put into parsing the phrases "significantly exacerbate" and "net effects" (or you don't have to: you can find various interpretations here and here and here.) One can only hope that the speechwriters (and one day we'll find out how much of a role Obama himself played in writing this climate change barn-burner) spent as much time carefully crafting these turns of phrase as the commentariat will spend deconstructing them.

Then again, it may all just be a lot of fine sounding hot air. There is no doubt, for example, that Keystone XL and the attendant expansion in oil production from tar sands would exacerbate carbon pollution, but how significantly? And does the fact that a pipeline is a more efficient way to transport oil compared to trains, tankers or trucks mean Keystone XL's "net effects" are positive or negative? Even the federal government itself is divided on those issues. The State Department's first crack at an analysis suggests that the pipeline would have a limited impact on CO2 pollution because the tar sands would get developed one way or the other anyway. Not so, counters the Environmental Protection Agency. So get ready for a good old inter-agency fight potentially.

Of course, that's the least of the EPA's worries now that they've been charged with what's already been called the "war on coal" (a war worth fighting if you care even remotely about climate change). As Obama noted, despite a mandate from the Clean Air Act and the legal blessing of the U.S. Supreme Court, there are at present precisely zero controls on greenhouse gas emissions from coal-fired power plants. That changes now (though the regulations only appear to bring such controls exactly to the CO2 output of a modern natural-gas fired power plant, which is still not zero. Fancy that.) To soften the blow, the plan also calls for $8 billion in loan guarantees for "clean coal," or rather any fossil fuel-fired power plant with CO2 capture and storage technology. Andrew Freedman has a nice FAQ on all the elements of Obama's climate plan.

But there is an inherent tension in what Obama's trying to do: he wants to both expand U.S. oil and natural gas production while bringing down CO2 emissions. That sort of “all of the above” energy strategy, as Obama has called it, or "both and" as he put it in his speech, is not a sure route to emission reductions.

Another alternative, as Mike Grunwald from Time is fond of pointing out, is the kind of new technology development and implementation funded by the American Recovery and Reinvestment Act, aka "the stimulus." That's how you cut carbon pollution in a hurry, and Obama was not shy about pointing out the achievements of the stimulus in this speech, such as doubling electricity generated from sunshine and wind.

The best part of all this speechifying is the fact that an American president finally had the wherewithal to condemn the lunatic fringe on the climate issue. "We don't have time for a meeting of the Flat Earth Society," Obama said.

That's because, as Obama noted earlier in the speech: "Those who are already feeling the effects of climate change don't have time to deny it -- they're busy dealing with it." That includes the U.S. taxpayer as well as the U.S. government itself, from the Department of Defense installing solar panels to help fortify bases against electricity interruptions to the Department of the Interior fast-tracking renewable energy projects like geothermal power plants on public lands. "Your federal government will consume 20 percent of its electricity from renewable sources within the next seven years," Obama promised. The U.S. will also stop funding new coal-fired power plants in the developing world that are not outfitted with the technology to capture and store CO2.

The worst part about all this? It's already too late. While U.S. energy-related CO2 emissions fell to the lowest level since the 1990s in 2012, the first quarter of this year saw a rebound of around 4 percent, thanks largely to an increase in coal burning. And it's not just CO2, there are also super-greenhouses gases like hydrofluorocarbons to deal with, particularly in countries like China and India, as well as methane. "Even if we Americans do our part, the planet will slowly keep warming for some time to come," Obama explained. "The seas will slowly keep rising and storms will get more severe." And we're locking in yet more for ourselves, our kids and generations to come while we wait for this long, slow transition to a clean energy future.

"As a President, as a father, and as an American, I'm here to say we need to act. I refuse to condemn your generation and future generations to a planet that's beyond fixing," the president promised. So as Obama and his administration weigh the Keystone XL pipeline and all the other infrastructure decisions to come, he might want to keep in mind a slightly tweaked version of the slogan of his predecessor Harry Truman (from the great state of Missouri, otherwise known as the "show me state," ahem): the CO2 stops here.