|Potential 1,500 mile pipeline could be 'essentially game over' for the climate [GALLO/GETTY]
It took some serious digging in the sock drawer, but eventually I found my 'Environmentalists for Obama' button left over from the '08 campaign. I needed it because I'm headed to Washington in a couple of weeks to get arrested in front of the White House, and I wanted to make sure I wouldn't be misunderstood.
I'm not alone - as many as a thousand people will risk arrest in daily protests at the White House over the last two weeks of August, making it the largest outbreak of civil disobedience in recent environmental history.
The target: a proposed 2,400 km pipeline from the tar sands of Alberta to the Gulf of Mexico. Those tar sands are the largest pool of carbon on the continent; the federal government's pre-eminent climate scientist, James Hansen, said recently that if we begin burning it in large quantities, it's "essentially game over" for the climate.
So in scientific terms it's a no-brainer (in fact, earlier this week more than a dozen of the nation's most senior climate scientists weighed in against the proposed pipeline). But in political terms? That's harder, because there's serious money at stake. Since the first permit must come from the State Department, for instance, it's probably no wonder that the pipeline consortium hired Hilary Clinton's former deputy campaign director as its chief lobbyist. And indeed, even before any data was collected, the secretary of state said she was 'inclined' to grant the permit.
There's real worry that the fix is in, especially since recently released WikiLeaks documents show American officials working with the tar sands companies to develop a strategy to 'spin' reporters and win favourable press coverage.
Still - the ultimate decision will rest with President Obama. Hence the sit-ins. And the buttons.
Because when you get right down to it, Obama has been a great enigma on the greatest crisis we've ever faced: the rapidly escalating heating of the planet.
On the one hand, his first stimulus package set aside some money for green investment (though a much smaller percentage than, say, China). And he's worked to persuade the auto companies he bailed out to raise mileage levels for their cars in the future.
But this is the guy who - the night he won the presidential nomination - said that with his ascension "the rise of the oceans would begin to slow, and the planet begin to heal". By that standard, he's not even close.
Not keeping promises
Earlier this year he opened up a vast swath of Wyoming to new coal mining. And he barely offered even lip service in support of the climate bill that foundered in the Senate; in the words of the widely-respected climate blogger Joe Romm, "Obama's overall record on energy and the environment deserves an F. Fundamentally, he let die our best chance to preserve a liveable climate and restore US leadership in clean energy - without a serious fight."
Of course, Obama can say with some justification that his weak record on the environment results in part from having to work with a Congress so dominated by the fossil fuel industry that it voted earlier this year to deny the very existence of global warming. Which is why this pipeline question is so politically key: this time, Obama gets to make the decision all by himself. He doesn't have to answer to Oklahoma Senator Inhofe ("global warming is a hoax") or Rep. Michelle Bachmann ("It's all voodoo, nonsense, hokum")
Because the pipeline crosses our border, he needs to sign a finding that it's in the national interest - and if he doesn't, then the Tea Party can't force him. The right wing has made it clear it wants the pipeline built, but unlike the recent debt ceiling negotiations, it has no leverage. It's all on Obama this time.
Which is why we'll be outside his house this August. Because we want to believe in the words of that skinny senator from Illinois during his campaign; because we want to show him the depth of the support he can call on if he stands up just this once to the fossil fuel industry. I'll wear my button with pride - and a little trepidation too.
Bill McKibben is one of the founders of tarsandsaction.org, which is organising this month's civil disobedience.
The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.