TransCanada Corp.’s long-delayed Keystone XL is an $8 billion project to construct an oil pipeline that connects Alberta in Canada to the U.S.’s Gulf Coast refineries. It’s faced years of objections from environmentalists but was eventually approved by U.S. President Donald Trump. The project has now hit another roadblock, in the U.S. courts.

1. What is the project?

The Keystone XL pipeline would span 1,179 miles (1,897 kilometers) from Alberta through three states -- Montana, South Dakota, and Nebraska -- before connecting to an existing network feeding crude to the Gulf Coast. The line would carry as much as 830,000 barrels of oil a day.

2. Why do environmentalists object?

Partly because of the nature of the fuel -- derived from what’s called “oil sands” by petroleum executives and “bitumen” by geologists. Its production and extraction emits more greenhouse gas than with conventional oil and, environmentalists say, would unacceptably add to global warming. They also highlight the risks to the water supply and general environment of piping the oil across the U.S. More broadly, they argue, the Keystone XL pipeline, by paving the way for more bitumen production, would help lock in dependency on oil for decades and delay a transition to renewable energy.

3. When did Trump approve the project?

In 2017. His predecessor, Barack Obama, had rejected a permit for the project in 2015 following eight years of angry debate. Then, just days after taking office, Trump announced actions to move the pipeline forward. That was not the end of the battle, though. Environmental foes vowed to press legal challenges. Also, TransCanada needs state approvals to begin work.

4. Who is objecting?

Nebraska created legal hurdles for TransCanada during the initial project review. But it was a federal court in Montana that put the project on hold in November, ruling that it needs a further environmental review by the U.S. State Department. The ruling came in lawsuits brought by the Indigenous Environmental Network, River Alliance and Northern Plains Resource Council. TransCanada joined the litigation to defend the permit approval.

5. What is Canada’s position?

Prime Minister Justin Trudeau favors construction of new pipelines — including Keystone XL — but has also taken steps to do more on climate issues, in the hope of winning over oil sands and pipeline opponents. Canadian oil has to sell at a discount to U.S. crude because of transportation constraints.

6. How dirty is the fuel?

Fuel produced from tar sands bitumen leads to the release of more carbon than conventionally produced fuel, partly because more energy is needed to extract and refine it. A Canadian clean-energy group, the Pembina Institute, said the difference could be as much as 37 percent; the industry and the Alberta government say it’s more like 6 percent. Oil companies say coal plants pump much more carbon dioxide into the atmosphere; environmentalists say the appropriate comparison is to conventional oil because, unlike coal, both kinds of crude are primarily used to make transportation fuel.

7. What’s Trump’s position?

Trump said at the time of his Keystone decision that it was a step toward making “the process much more simple for the oil companies and everybody else that wants to do business in the United States.”

--With assistance from Dan Murtaugh.

To contact the reporters on this story: Grant Clark in Singapore at gclark@bloomberg.net;Andrew Harris in Washington at aharris16@bloomberg.net

To contact the editors responsible for this story: Alexander Kwiatkowski at akwiatkowsk2@bloomberg.net, Ramsey Al-Rikabi, Paul Geitner

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