Climate change protestors flood National Mall

“You look beautiful!” boomed Van Jones, in his trademark square glasses.

President Barack Obama’s former green-jobs czar, surrounded by loudspeakers on stage at the National Mall, was speaking to a crowd of more than 40,000, massed in shivering Washington cold yesterday to protest climate change.

Bill McKibben, leader of and one of the event’s organizers, told demonstrators, “You are the antibodies” who can “stop the world’s fever.”

Many of the participants were there to protest specifically the Keystone XL Pipeline, which would deliver oil from Canada to the United States. (RELATED: Sierra Club executive bragged that “130 buses” brought activists to Washington)

A protester from Maryland said it is time for President Obama to choose between fossil fuels and renewable energy. Another, from Vermont, proposed dismantling the rest of the country’s pipelines, after defeating Keystone XL. A third, from Kentucky, even suggested instituting a national hitchhiking system to reduce carbon emissions.

Students from 256 colleges reportedly attended the rally, along with more than a dozen masked grim reapers, who gripped scythes and prowled the crowd.

Dark imagery stalked good vibrations elsewhere at the event, as well.

Not long after Jones came on stage, he compared the Keystone pipeline to “jabbing a dirty needle into the arm of the country.” (RELATED VIDEO: Senator says Obama’s promise to act alone on climate change is “threat to democracy”)

The “Celebrity Climate Activist,” as’s program described him, even attacked the president who helped make his name. He called the Keystone pipeline a “carbon bomb.”

Actress Rosario Dawson told the crowd that the government is withholding secrets about the pipeline. Then she said she prefers things “above ground, not under it.”

“Stop being chumps,” Jones teased the people he had called “beautiful” a minute before.

He said they had failed President Obama by failing to motivate him to act on the issue.

“All the good you have done will be wiped out by floods, fires and super-storms, if you fail to act on this,” Jones said, addressing President Obama directly. “History will judge you based on this one decision.”