"If you want to keep oil in the ground, we have to address what kind of cars we want to drive," Amy Myers Jaffe, an energy policy analyst at the University of California at Davis, said in an interview with National Geographic published Sunday.
Targeting infrastructure might not be the best way to change national energy and climate policies, Jaffe said.
TransCanada's cross-border Keystone XL pipeline proosal was submitted for federal review more than five years ago and has been the target of mounting environmental criticism.
More than 200 protest vigils were held across the country after a recent U.S. State Department review of the plan found it would have few major environmental impacts.
Opponents say the heavier grade of Canadian crude oil designated for Keystone XL comes with too many risks.
Michael Brune, executive director of the Sierra Club, said high-profile campaigns may be more effective than taking on energy policies that may be difficult for some people to understand, the report said.
Keystone XL needs federal approval as a cross-border pipeline. President Barack Obama said he'd weigh the pipeline against its environmental footprint.