Ultimately, if we're going to prevent large parts of this Earth from becoming uninhabitable in our lifetimes, we're going to have to keep some fossil fuels in the ground rather than burn them and release more dangerous pollution into the sky.
President Obama today denied Canadian oil company TransCanada a presidential permit to construct the Keystone XL, a pipeline that would have carried Canadian tarsands oil into the USA.
Obama announced his refusal in his Rose Garden address today, citing the pipeline's projected contribution to climate change - and deeming it not in the national interest.
"After extensive public outrage and consultation with other cabinet departments, the State Department has decided that the KXL pipeline would not serve the national intersts of this country", said Obama. "I agree with that decision."
He explained that the pipeline - which would have run 1,200 miles from the Alberta tarsands vis Texas to Nebraska - "would not make a meaningful long term contribution to our economy." Instead he urged bipartisan support for a full-scale renewal of the US's crumbling national infrastructure.
Nor, added Obama, would KXL serve to reduce fuel costs: "The pipeline would not lower gas prices for American consumers. In fact, gas prices have already been falling, steadily.
"America is now a global leader when it comes to taking serious action to fight climate change, and frankly approving this project would have undercut that leadership", Obama continued.
"Today, we're continuing to lead by example. Because ultimately, if we're going to prevent large parts of this Earth from becoming not only inhospitable but uninhabitable in our lifetimes, we're going to have to keep some fossil fuels in the ground rather than burn them and release more dangerous pollution into the sky."
The move may also be motivated by the forthcoming Presidential election. Both leading Democratic candidates, Hillary Clinton and Bernie Sanders, have taken strong anti-KXL positions. And both have seized on climate and energy as a key point of differentiation between their Republican adversaries who are overwhelmingly pro-fossil fuel and 'climate skeptic'.
Joy as seven-year campaign culminates in victory
The Presidential announcement follows seven years of intense public campaigning that has included grassroots opposition in the states to be crossed by pipeline.
"This is an extraordinary moment for grassroots activism and the fight against fossil fuels", said Friends of the Earth President Erich Pica. "For seven years, people from around the United States campaigned together to transform a previously routine decision to approve a pipeline into a leadership test on climate change.
"With this decision, President Obama has taken leadership in significantly slowing the expansion of the tar sands industry. We have not only succeeded in stopping the Keystone XL pipeline, we've awakened a grassroots climate movement.
Ben Schreiber, head of climate & energy at FoE US, said he believed the decision to be inevitable based on climate change alone. "The President set up a climate test and it was clear the KXL pipeline could not pass it. As soon as he set that test the project was heading for a refusal."
"It's no accident that this decision has come just weeks before the Paris climate conference", he added. "Clearly Obama wants to use this decision to send a message that the US is serious on climate change."
Only last week, he said, TransCanada had smelled defeat and tried to withdraw its application so it could resubmit it under the next President in the hope of an approval. "But they failed. And now this refusal is final. There is no appeal and no second chance."
We must keep fossil fuels in the ground!
"Today marks the beginning of a new paradigm", said Lindsey Allen, Executive Director of the Rainforest Action Network. "The president of the United States affirmed that the only way to stop the worst impacts of climate change is to leave fossil fuels in the ground.
"If Keystone XL had been fully built, it would have carried 800,000 barrels a day of toxic tar sands bitumen from the oil sands fields of Alberta, Canada, across our entire country. President Obama vowed that the pipeline wouldn't be built if it it added significantly to the problem of climate change.
"The evidence clearly showed that the pipeline would be 'game over' for the climate. But for years, insiders predicted that Keystone’s approval was a done deal. But you took action, and proved them wrong."
350.org Executive Director May Boeve added: "President Obama's decision to reject Keystone XL because of its impact on the climate is nothing short of historic - and sets an important precedent that should send shockwaves through the fossil fuel industry.
"Just a few years ago, insiders and experts wrote us off and assured the world Keystone XL would be built by the end of 2011. Together, ranchers, tribal nations, and everyday people beat this project back, reminding the world that Big Oil isn't invincible.
"Everywhere you look, people are shutting down fracking wells, stopping coal export facilities, and challenging new pipelines. If Big Oil thinks that after Keystone XL the protesters are going home, they're going to be sorely surprised.
"If it's wrong to build Keystone XL because of its impact on our climate, it's wrong to build any new fossil fuel infrastructure, period. Our movement simply will not rest until our economy shifts away from the dirty fossil fuels of yesterday to the clean renewables of tomorrow."
Oliver Tickell edits The Ecologist.
See the full Presidential statement on KXL.