Environmental groups on both side of the border are hoping to use the current public concern over climate change in the U.S. as a key weapon in their renewed campaign against the Keystone XL pipeline.

They've released two new reports in Washington that claim the pipeline would be instrumental in triggering a tripling of production in Alberta's oil sands by 2030 and would contribute more greenhouse gases than originally estimated.

They're hoping to persuade the Obama administration to reject the construction of the northern leg of the pipeline that would carry oil from Alberta.

"We don't view this as an inevitable approval," said Danielle Droitsch from the U.S. environmental group Natural Resources Defence Council. "With climate change chaos sweeping the nation, this new research shows why the Obama administration should stop the Keystone XL tarsands pipeline in its tracks."

The U.S. State Department is expected soon to release its Supplemental Environmental Impact Statement on the new route proposed by TransCanada Pipeline for the northern portion of its XL pipeline through Nebraska.

The project was rejected by U.S. President Barack Obama a year ago after a public outcry over the possible environmental impacts on Nebraska's sensitive underground aquifers.

In the meantime, the company received approval to split the project in two and continue the construction of the southern section from Cushing, Oklahoma to Houston, Texas.

Saskatchewan Premier Brad Wall and 10 U.S. governors have sent a letter to Obama urging him to approve the Keystone XL project.

Emissions 'underestimated by 13%'

Speaking at the National Press Club in Washington, the coalition of environmental groups released a report that claims oil sands crude is a lot dirtier than the industry lets on.

Oil Change International says its report “Petroleum Coke: The Coal Hiding in Tar Sands” shows the by-product of the oil sands bitumen should be included in the well-to-wheel analysis of the greenhouse gas footprint of the oil sands.

Petroleum coke or petcoke is produced when the bitumen is refined. It’s a solid, coal-like substance that is used in U.S. refineries as cheap energy.

Protestors from the Tar Sands Blockade sit in the lobby of a building in Houston, Texas that contains an office for TransCanada's Keystone XL pipeline project on Jan. 7. (Cody Duty/Houston Chronicle/AP Photo)

“The burning of this coke has not been calculated into the overall calculation of emissions,” said Lorne Stockman, research director at Oil Change International.

“The total emissions have been underestimated by at least 13%. Pet coke is making the tar sands dirtier and cheaper,” he says.

Stockman estimates that replacing 830,000 barrels per day of conventional crude with Alberta’s oil sands crude in the Keystone pipeline would increase U.S. emissions equivalent to adding nearly six million cars to the road every year.

But the oil industry says the heavy oil from Canada that produces petcoke is simply replacing heavy oil being used in U.S. refineries that comes from Mexico and Venezuela.

"The amount of petroleum coke being produced by those refineries is exactly the same," said Greg Stringham, vice-president of the Canadian Association of Petroleum Producers.

"It is being used today, that is correct, it is part of the mix," he said in an interview from Calgary. "Whether it comes from offshore or heavy oil out of Canada, it is the same amount of petroleum coke that comes out of these refineries."

Keystone XL 'enables' growth

The Pembina Institute also argues that emissions will go up as direct result of the Keystone Pipeline. Its new report disputes the State Department's original conclusion that if the Keystone weren't built, the oilsands would ramp up anyway.

"The last EIS (Environmental Impact Statement) said there would be no increase in climate emissions, because other transportation options will simply move ahead. That's not true. The Keystone XL is the biggest and most imminent pipeline on the table," said Nathan Lemphers from the Pembina Institute.

"Keystone XL will have the greatest impact and will allow a 36 per cent increase in oilsands production," he said. "So that tells the story that the pipeline is a key enabler of oilsands growth."

The industry says it's not worried about renewed efforts to try to stop the Keystone pipeline, calling it "just a continuation of the dialogue" that's been going on for years about the XL pipeline.

"There is a belief by some the expansion of Canadian oil into the U.S. will increase the amount of oil the U.S. is consuming, and that is not the case at all," said Greg Stringham of CAPP.

"We do see a change in the energy mix happening... for us, this question about Keystone expansion down to the Gulf is a question of where Americans buy their oil, where they get it from, not a question of how much they use — that's their decision."

Environmental groups are hoping to tap into public sensitivity to climate change after a summer of drought in both Canada and the U.S. Last fall's Hurricane Sandy was linked to extreme weather caused by a changing climate.

The groups are planning a major protest outside the White House on February 17.