Hurricane Irene becomes a powerful symbol for activists fighting the Keystone XL pipeline.

When a hurricane swamps a climate-change protest, it’s “Irene-ic,” quipped activist and author Bill McKibben this morning.

“There are a ton of people going up and down the East Coast who’ve never dealt with a hurricane before, for whom it’s an entirely new thing. That’s the way climate change is,” he said this morning as a crowd gathered for a rainy rally in front of the White House.

Hurricanes are an iconic symbol of climate change—they become fiercer, more frequent, and more devastating the more carbon we pump into the atmosphere. Already, Category-5 hurricanes (the most severe kind) are happening three to four times more often in the North Atlantic than a decade ago. In 2005, Hurricane Katrina was a wake-up call for many people about why we need action on climate change.

The protests are iconic in another way. The climate-change protesters have assembled here every day for the last week in what McKibben calls “the largest collective act of civil disobedience in the history of the climate movement.” The activists are pressuring Obama to stop construction of the Keystone XL pipeline, which will transport bitumen from Alberta to the Gulf of Mexico. The pipeline would open an artery to Canada’s tar sands fields—one of the world’s largest, most costly, and most polluting sources of oil.

McKibben has likened the protests to Martin Luther King Jr.’s civil rights battles: He has used the unveiling of the King memorial in Washington, D.C., this week to draw parallels between human rights and environmental equity. In a joint op-ed in yesterday’s New York Daily News, McKibben, Van Jones, and Lennox Yearwood write, “We believe King, who as his life progressed embraced the anti-war cause and showed his solidarity with poor people all over the world, would have joined in the fight against climate change, which is already wreaking havoc on those living closest to the margin.”

The action has impact because of its seriousness more than its size. It spans two weeks and the demonstrators include an array of celebrities, scientists, experts, and ordinary folks. Each day, a chosen few stand at the White House gates and quietly submit to arrest—381 have been hauled to jail so far, then released. McKibben was among the first group detained and was held for several days. Margot Kidder, the actor who played Lois Lane in the Superman films of 1978 and 1980, was also arrested this past week.

Today the crowd was small—dozens, probably no more than 100 people. They had called off the civil disobedience portion of the rally—protesters agreed that they wouldn’t hamper the police’s ability to deal with potential emergencies brought on by the hurricane. I expected only dyed-in-the-wool veteran activists to appear in the midst of apocalyptic weather warnings, but the crowd was mixed. I noted a lot of 20-somethings, a granny in a rain bonnet, a number of Baby Boomers, and everyone in between, including a contingent that had traveled from Alberta to speak first-hand about the devastating impact of tar sands mining. McKibben called out a couple who were celebrating their 34th wedding anniversary. I spoke to a 24-year-old consultant in a button-down shirt and khakis: He had planned to look respectable in case he got arrested today. And I met a couple in their mid-50s who had made their first foray into political activism in 2008. They were so enthusiastic that they spoke over another. “It was the first time in my life. I’ve never done political stuff before,” he told me. “We were incredibly excited by Obama,” she said. “We just wish he would hold firm,” he said.

After a few speeches, several cheers, a few choruses of “We Shall Overcome,” and some shouts and sign-waving, the group disbanded, but they will return on Monday, and day after day in the coming week, attempting to bend the ear of the Obama administration, which has sole authority to halt Keystone XL.