Sierra Club executive director Michael Brune also was arrested—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.
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.
"We want to send a strong message that we expect the president's ambitions to meet the scale of the challenge and reject a pipeline that carries dirty, thick oil" that contributes to global warming, Brune said.
The made-for-media protest came ahead of a rally planned for Sunday on the National Mall, where organizers are expecting at least 20,000 people to protest the tar sands pipeline and urge Obama to act forcefully on climate change.
Kennedy, president of the Waterkeeper Alliance, a New York-based environmental group, said he was being arrested "with regret," noting that he would prefer to contest the pipeline in court—and may eventually do so.
Kennedy, whose father was an attorney general and U.S. senator, called the pipeline "a boondoggle of monumental proportions" that will "ruin the lives of millions of people," through increased carbon pollution and likely spills.
Obama was visiting a manufacturing plant in North Carolina when the demonstration occurred. As he made his way to a factory in Asheville, protesters held signs saying "Stop coal" and "No to Keystone."
Obama has called climate change a serious threat and in his State of the Union speech Tuesday night urged Congress to combat the phenomenon. If Congress fails to act, he will use executive authority to take steps to cut greenhouse gas pollution and encourage increased use of cleaner sources of energy, Obama said.
Obama has twice thwarted the Keystone XL pipeline because of concerns over its route through sensitive land in Nebraska, but has not indicated how he will decide on the pipeline now that Nebraska's governor has approved a new route. The State Department has authority over the project, because it crosses an international border, but most observers expect Obama to make the final decision.
Bond, former chairman of the NAACP, said he participated in the pipeline protest "because I'm an American and I'm worried about the planet." He called the pipeline a human-rights issue, since many landowners in the six states where it will travel have been unable to resist Calgary-based TransCanada, the pipeline operator, as it seizes their property.
Bond also said the pipeline will exacerbate pollution problems near the Houston refineries where it will be processed, including neighborhoods where minorities predominate. The pipeline will travel through Montana, South Dakota, Nebraska, Kansas and Oklahoma before reaching Texas.
Bond, 73, said he was unhappy at the prospect of being arrested. "My mother told me I'd never get a job" if he got arrested, he said.
As Bond and others were being arrested, the American Petroleum Institute, the largest lobbying group for the oil industry, again urged Obama to approve the project. The group said it will pay for ads supporting the pipeline and will mobilize grassroots events across the country urging Obama's approval.
API President Jack Gerard called Keystone XL "the most thoroughly vetted major infrastructure project in the nation's history" and noted that TransCanada has agreed to 57 special conditions sought by the U.S. government to ensure environmental safety.
With the unemployment rate hovering near 8 percent, "getting people into these new jobs is critical," Gerard said.
In the past week, nine people have been arrested in attempts to disrupt the pipeline's construction through Oklahoma. One of the eight people arrested Monday near Schoolton, Okla., had attached himself to a crane and was freed by a firefighter using bolt cutters.
Associated Press writer Josh Lederman in Asheville, N.C., contributed to this report.
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