“We’re expecting to hear the same conclusion that we’ve heard four times before: no significant impact on the environment,” Jack Gerard, API president, told Reuters in an interview last week.

Most indications for some time have been that the updated report will hew close to last year’s draft, which said the project will not add substantially to carbon emissions.

That is sure to disappoint environmentalists. But the report is likely to show a nuanced interpretation of the environmental benefits and costs of Keystone.