04/25/2014 10:00 am ET Updated Jun 25, 2014

'Cowboys and Indians' Unite Over Keystone XL

The Cowboy and Indian Alliance have descended on Washington, DC to protest against the controversial Keystone XL pipeline which hopes to transport the world's dirtiest oil from the Canadian tar sands down to refineries in the Gulf of Texas.

Riding on horseback, wearing American Indian headdresses and cowboy boots, the protesters rode into the U.S. capital on Tuesday, where they marched downtown before setting up camp on the National Mall. Complete with tipis, sacred fires and religious ceremonies, the Mall has now been transformed into a scene out of an Old Western.

Over the past couple of the days, the protesters -- made up of ranchers, farmers and indigenous tribes -- have been performing water ceremonies, to highlight the risk that the tar sands pose to water sources along its 1,179 mile route.

The five-day gathering will end with a march to the White House this Saturday when the protesters will be joined with thousands of other concerned citizens, to call on Barack Obama to reject what has been dubbed as the "largest carbon bomb" on the planet.

The protest was originally designed to coincide with the president's final verdict on Keystone XL. But last Friday, his administration kicked that ruling into the long grass yet again.

According to the State Department, it will make its final conclusion once a legal dispute over the project's Nebraska route has been settled.

The move came two days after former U.S. president Jimmy Carter joined nine Nobel laureates, urging Obama to reject the pipeline. In a letter to both the president and Secretary of State John Kerry, they described Keystone as a "critical choice":

"You stand on the brink of making a decision that will define your legacy on one of the greatest challenges humanity has ever faced -- climate change. As you deliberate, you are poised to make a choice that will signal either a dangerous commitment to the status quo, or bold leadership that will inspire millions counting on you to do the right thing for our shared climate."

Their collective call for action came two weeks after the United Nations released its most sobering account on the state of our climate yet: "Nobody on this planet is going to be untouched" warned Rajendra Pachauri, the head of the group's Intergovernmental Panel on Climate Change.

"Things are worse than we had predicted. We are going to see more and more impacts, faster and sooner than we had anticipated," said Saleemul Huq from the Independent University in Bangladesh.

That brutal assessment came six months after the UN warned that our planet is warming much faster than expected: temperatures may now breach the upper safe limit of warming within the next thirty years.

"Unless we act dramatically and quickly, science tells us our climate and our way of life are literally in jeopardy. Denial of the science is malpractice," warned John Kerry.

Last June, Obama promised that he would not approve the pipeline if it seriously "exacerbates the problem of carbon pollution" that is threatening our planet.

Eight months later, the State Department concluded that it will not have a "significant" impact on CO2 emissions.

That assessment drew widespread ire from the environmental community.

According to the EPA, oil from the Canadian tar sands releases over 80 percent more greenhouse gases than conventional sources of crude. That's because it requires huge amounts of energy to extract, transport and refine.

"To say that the tar sands have little climate impact is an absurdity. The total carbon in tar sands exceeds that in all oil burned in human history," warns James Hansen, NASA's former top climate scientist.

In fact, Canada's tar sands hold seven times more oil than proven reserves in Saudi Arabia. And, if the world burns all of it, global temperatures will rise by 0.4 degrees Celsius. That marks half of the warming already experienced by our planet.

"This is why, no matter where you live, it is appalling that the U.S. is debating whether to approve this massive pipeline. If the negative impacts of the pipeline would affect only Canada and the U.S., we could say good luck to them. But it will affect the whole world, our shared world, the only world we have," wrote Nobel Peace laureate Desmond Tutu in the Guardian earlier this month.

Although pipeline supporters argue that Canada will develop its tar sands with, or without the pipeline, the project will only encourage the country to exploit it at a much faster rate: It's expected to carry 1 million barrels of oil per day by the end of this year.

Other modes of transport, such a rail, will not be in the offing until 2030.

Although there is no deadline for when the president must make his decision, he is widely expected to make it after this year's mid term elections.

If the president backs Keystone ahead of that time, he risks infuriating his Democratic base who were essential to getting him elected in 2008 and 2012. Worried about the tar sands' effect on climate change, they have strongly urged Obama to cancel the project.

Yet on the other hand, if Obama rejects the pipeline, he will undermine several Democratic Senate campaigns in Louisiana and Alaska. Both oil states are crucial to determining the balance of power in Congress this fall.

Republicans, who control the House of Representatives, are desperate to regain control of Congress as this would spell doom for Obama's final two years in office.

Both sides of the political aisle regard the State Department's latest delay as a move to boost the president ahead of the midterms. "Sometimes the art of politics is the art of delay," says Kalee Kreider, a D.C. consultant who works on climate issues.

Although Obama's efforts to slash emissions from power stations is a more effective way to tackle climate change in the long run -- they account for nearly a third of America's greenouse gases -- such regulations may take years to come into effect. Keystone, on the other hand, is a decision that the president can make with the stroke of a pen.

In his own words: "That bright blue ball rising over the moon's surface, containing everything we hold dear -- the laughter of children, a quiet sunset, all the hopes and dreams of posterity -- that's what's at stake. That's what we're fighting for. And if we remember that, I'm absolutely sure we'll succeed."