The State Department granted a permit Friday for construction of the controversial Keystone XL Pipeline, following years of heated debate. The decision reversed former president Obama’s order in 2015 to block the project.

TransCanada, the Canadian-based company that fought to win approval of the pipeline, announced that Tom Shannon, the State Department’s undersecretary for political affairs, issued the approval.

“This is a significant milestone for the Keystone XL project,” TransCanada’s president and chief executive, Russ Girling said. “We greatly appreciate President Trump’s administration for reviewing and approving this important initiative, and we look forward to working with them as we continue to invest in and strengthen North America’s energy infrastructure.”

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The approval comes only two months after President Trump signed an executive order to reintroduce the Keystone XL and Dakota Access Pipelines. Today’s signing makes way for the completion of the project, which will move around 830,000 barrels of crude oil from Canada to refineries on the Gulf Coast per day.

The move is one of the first steps taken by the administration that purportedly prioritizes job development over environmental concerns.

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Groups in opposition to the pipeline argue that the extraction of crude oil from oil sands pumps about 17% more greenhouse gases into the atmosphere than standard crude oil extraction. Environmentalists also agree that it would be hurt the freshwater supply from Ogallala Aquifer, which the pipeline would cut across.

Still, the State Department concluded earlier that the pipeline would have no affect on climate change.

Instead, in 2015 they found that the project would directly and indirectly create 42,000 jobs, but would bring just 3,900 construction jobs if it was completed in one year.

Only 50 permanent jobs would be created.

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As Executive director of Greenpeace USA, Annie Leonard, said: “The Trump administration may be furiously propping up an obsolete energy system at the behest of his fossil fuel cronies.”

The pipeline would also cut across South Dakota and Montana. In Nebraska, it would converge with other pipelines that lead to refineries along the Texas Gulf Coast, potentially damaging the fragile Sand Hills prairie region.

The company said construction is still waiting upon a final permit from Nebraska’s Public Service Commission. The pipeline would not be completed until mid-2019.

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“America’s now a global leader when it comes to taking serious action to fight climate change,” Obama said in November 2015. “And frankly, approving this project would have undercut that global leadership. And that’s the biggest risk we face — not acting.”

The approval of the pipeline represents a giant step backwards in environmental protection.