On January 24, President Trump signed an executive memorandum inviting the Canadian firm TransCanada to resubmit its application to the Department of State for a presidential permit for the Keystone pipeline project, thus resurrecting a project that was, after much debate, shut down in 2015 by then-President Obama. First, what are the mechanics of approval for this second permit—can you walk us through the process?

The first step is for TransCanada to reapply for a permit, and the company has already announced that it is doing so.  The new President will have the ultimate authority to approve a permit and could do so without much further evaluation because the environmental review has already been completed.  But the President had indicated he wants to negotiate a commitment to use more American-made steel in the pipeline.  Such negotiations could take time—or maybe the deal has already been struck.  We don’t really know.  In addition to federal approvals, state approvals in Nebraska and approvals in Canada, at the very least, are still necessary.  And almost certainly we can expect lawsuits over all these approvals.

The proposed pipeline would carry approximately 800,000 barrels of Canadian “tar sands” oil from Canada to the Gulf Coast. What are the environmental concerns, if any? And are they significant enough to stop the project?

The two biggest environmental concerns are (1) the risk of leaks and spills, which exists for virtually all oil infrastructure, as we saw with the BP spill in the Gulf and the Exxon Valdez spill in Alaska, and (2) the increase in greenhouse gas emissions from Alberta tar sands, which have been estimated to be 17 percent greater than emissions associated with an equivalent amount of average crude oil.  It was really the climate change impacts that drove President Obama’s denial of the project, but those concerns may not be a priority for the new President.