A senior writer for Barack Obama's 2008 presidential campaign was arrested outside the White House on Monday after he joined a protest against a planned Canadian tar sands pipeline.

Elijah Zarlin, who authored fundraising emails for Obama, was arrested along with more than 100 other protesters taking part in a series of demonstrations against the planned $7-billion Keystone XL pipeline.

"The Keystone pipeline, if he approves it, is going to cast a huge shadow over our future," he told The Atlantic. "It's his decision, and this is the type of thing that when he was on the campaign trail and telling staff at headquarters that we literally had to work nonstop over the next four months, that this was a must-win election, this was one of the issues we wanted to make an impact on -- climate change."

NASA's top climate scientist Dr. James Hansen, Greenpeace Executive Director Phil Radford, president of CREDO Mobile Michael Kieschnick and 350.org Executive Director May Boeve were among those arrested on Monday.

On Tuesday, Actress Daryl Hannah was arrested along with more than 100 others, bringing the total amount of arrests up to 595.

"We stand here today to just say no to slavery, to just say no to tar, sands, oil, and no to the Keystone pipeline," Hannah said before her arrest.

The pipeline would transport 500,000 barrels of crude per day from America's neighbor to the north all the way to the Gulf coast of Texas.

A U.S. State Department environmental impact study released last week claimed the pipeline would have a minimal effect on the environment, and officials maintained that even if the U.S. refuses the pipeline, Canada will just sell their oil elsewhere.

Canadian tar sand is seen as a horribly inefficient form of hydrocarbon energy due to the separation process, which requires more energy than the finished product puts out. Production methods also put off 3-5 times more greenhouse emissions than typical oil production. Spills are another concern with 1,600 mile long pipeline.

Obama’s press secretary Jay Carney said Tuesday he hadn't talked to the president about the pipeline.

"I don’t have anything new on that," he said when questioned by reporters.. "I believe the State Department has — that’s under the purview of the State Department presently, but I don’t have anything new on that."

Obama must personally approve the plan. He has not issued a decision on the pipeline, but one is expected before the end of this year.

With prior reporting by Stephen C. Webster. Image courtesy of Ben Powless.