Previously in the Pipe: What a difference a couple years can make. Planning for the Keystone XL Pipeline had slowed to a trickle in November 2011, after the U.S. State Department announced it would halt permitting on the hotly contested project to assess possible environmental and health impacts of the 1,700-mile pipeline.

The move appeared to be a political maneuver by President Barack Obama to put off the controversial decision until after his bid for reelection in 2012. Obama had said he would approve the project if the pipeline—which would carry about 830,000 barrels per day of tar sands crude from Alberta, Canada —would not significantly exacerbate greenhouse gas emissions.

In the meantime, builders of the pipeline attempted to ameliorate one of the major concerns by changing the Keystone Route to avoid Nebraska’s environmentally important Ogallala Aquifer and the wetlands of the Sand Hills. The change allowed Nebraska Gov. Dave Heineman get behind the project, according to a letter he wrote to President Obama in January of 2013.

Since then, supporters of the project and those that opposed it have continued to debate its merits and drawbacks. Supporters have pointed to a series of rail accidents as need for a pipeline, while opponents have held up pipeline breaks as reason to be cautious.

Piping Hot Now: The debate is poised to heat up now that the State Department released its Final Supplemental Environmental Impact Statement last week. On the question of greenhouse gases, the 11-volume report found that while extracting the tar sands would increase greenhouse gas emissions, extraction would likely occur at the same rate whether the pipeline was built or not.

That assessment should open the door for approval of the project based on Obama’s previous comments, pipeline supporters say. Opponents, however, dispute the report’s objectivity and point to a pending investigation into an earlier version as reason not to jump to conclusions, according to the New York Times.

Down the Pipeline: The report is only one piece to be considered as the permitting process begins to ramp back up, according to the State Department website. Because of the international aspects of the pipeline, Secretary of State John Kerry will need to make a recommendation on whether the pipeline serves the national interest. That includes factors such as energy security, environmental and economic impacts, and foreign policy.

Kerry’s office will also coordinate feedback from eight U.S. agencies, including the Environmental Protection Agency, the Department of Defense, and the Department of Energy, according to the Washington Post. Public comments are also being accepted until March 7, 2014.