It was famed Vermont activist and author Bill McKibben who led the 35,000-strong "Forward on Climate" march in Washington on Sunday. But it was the scores of uncelebrated Vermonters who helped infuse the largest-ever outpouring of its kind with a vocal mixture of hope and fear.

Three buses filled with students from the University of Vermont and from Middlebury and St. Michael's colleges made the 23-hour round trip along with three more buses carrying Vermonters of all ages. They came to urge President Obama to stop the proposed Keystone XL pipeline that would pump oil extracted from Canadian tar sands 1700 miles to the Gulf of Mexico. Tar sands oil is an especially carbon-rich fossil fuel that, opponents warn, could push the climate crisis to a tipping point.

But the rally alongside the Washington Monument and a subsequent march around the White House were motivated by more than the Keystone project. There were loud and urgent calls for investment in clean forms of energy, making the event feel at times like a wonky exercise in lobbying. But plenty of raw emotion was expressed on a bitterly cold afternoon.

"I don't want to bring children into a world they can't live in," said Corinne Almquist, a Middlebury vegetable farmer and Nordic ski instructor who plans to become a midwife. "Climate change is the biggest issue of all. It affects everything."

Gary Beckwith of Richmond also expressed worry about how a hotter, more tempestuous planet will affect the lives of his own three children and "all the children of the world." But climate change "isn't just about the future," said the inventor of a bus that runs on solar energy. "It's about today. It's happening now."

Maeve McBride marched with her 6-year-old son, Phinn, and with her parents, John McBride and Nancy Shatzkin. "I'm so proud of Maeve's work on this issue," her father said, referring to his daughter's role as an organizer of the Vermont chapter of 350.org, the group that sponsored the rally. "It's her generation's issue, but it's something we all have to address."

Tar sands oil could one day be pumped through an existing pipe that runs across the Northeast Kingdom, noted Ruby Perry of Burlington. "But this isn't NIMBY. There's no more NIMBY on an issue that affects the whole planet."

Vermonters brought to the nation's capital not only their trademark green activism — symbolized by the green 350.org ski caps many were wearing — but also a blast of old-fashioned February weather. A 30-mile-an-hour wind knifed across a 25-degree National Mall, occasionally shredding placards and ripping flags from poles. Conditions were not ideal for persuading skeptics to accept the scientific data on global warming.

It was also a day of political ambivalence for many participants. Speeches alternated between affirmations of Obama's environmental record and criticisms of his inaction on climate change —sometimes in the same speech.

Van Jones, who had worked on environmental issues in the White House, told the crowd that Obama has succeeded in many respects, but he also led his listeners in a chant of "Don't be chumps!" Jones was implicitly warning against being seduced by smooth rhetoric meant to mask coarse deeds.

"Separation of oil and state" was a theme of the Sunday upwelling. The slogan was emblazoned on a mock up of the Keystone pipeline that looked like a snake float in a Chinese New Year's parade. And as they neared the White House, marchers shouted, "Obama, come out, We've got some stuff to talk about."

The president is expected to decide the fate of the Keystone pipeline within the next few months.

Photos courtesy of Greg Dennis and 350.org