Actor Mark Ruffalo was one of an estimated 10,000 protesters who surrounded the White House on Sunday to fight the Keystone XL pipeline, telling HuffPost, "We invite the president to make good on his promises of a real renewable energy policy for the United States."
The pipeline project, which has come under increasing scrutiny, is currently proposed to carry oil from the tar sands in Alberta, Canada to Texas refineries.
President Obama said last week that he will be making the decision on the pipeline's permit based on both economic and health factors.
In October, Ruffalo spoke at the Occupy Wall Street protests, inviting listeners to join the Keystone XL protests to "remind Obama to unlink his arms with the corporations, the gas and oil industry and entwine his arms with the people he is in charge of taking care of."
At the Keystone White House protest, Ruffalo said, "We've entered this era of really radical and environmentally harmful forms of extraction." He was also active on Twitter during his time at the protest. At one point, he tweeted:
At the protest, John Bolenbaugh, a Keystone employee-turned-pipeline activist from Michigan told HuffPost's Lucia Graves, "I will not accept a job for a tar sands pipeline. I will not do it because I’ve seen the devastation and the sick people from what a tar sands spill does when there is a leak and there’s gonna be a leak. It’s gonna happen sooner or later."
Various celebrities ranging from Julia Louis-Dreyfus to Robert Redford have spoken out against the pipeline, and invited concerned citizens to participate in the Tar Sands Action protests this past Sunday.
View the slideshow below for more prominent figures who are fighting the Keystone XL pipeline: