By MATTHEW DALYWASHINGTON (AP) â¿¿ Celebrities and environmental activists, including lawyer Robert F. Kennedy Jr. and civil rights leader Julian Bond, were arrested Wednesday after tying themselves to the White House gate to protest the Keystone XL oil pipeline from Canada. Sierra Club executive director Michael Brune also was arrested â¿¿ the first time in the group's 120-year history that a club leader was arrested in an act of civil disobedience. The club's board of directors approved the action as a sign of its opposition to the $7 billion pipeline, which would carry oil derived from tar sands in western Canada to refineries along the Texas Gulf Coast. Activist Bill McKibben, actress Daryl Hannah and NASA climate scientist James Hansen also were arrested, along with more than 40 others. They were charged with failure to disperse and obey lawful orders, and released on $100 bond each. The protesters are demanding that President Barack Obama reject the pipeline, which they say would carry "dirty oil" that contributes to global warming. They also worry about a spill. Many business and labor groups support the 1,700-mile pipeline as a source of jobs and a step toward North American energy independence. The 4-year-old project has become a flashpoint in the debate over climate change, with opponents labeling it a "carbon bomb" that could trigger global warming. Supporters call that rhetoric overblown and say Obama should approve the pipeline as part of his "all of the above" energy policy, which encourages a wide range of domestic energy development. In an interview before his arrest, Brune said civil disobedience was justified because of the threat posed by tar sands oil, which is difficult to produce and emits significantly more greenhouse gases than conventional oil. The Sierra Club is the nation's oldest and largest environmental group and generally shies away from extreme tactics.