Filmmaker Jerry Rothwell seemed to be in a great spirits as he talked about his opening-night Sundance Film Festival documentary “How To Change The World” with The Park Record from his home in London last week.

The usual angst one might sense from a filmmaker during the week prior to festival was nowhere to be found as his “Sundance cut” was already “in the can” and set to premiere Thursday night, Jan. 22, at the MARC Theatre in Park City.

His laughter-punctuated observations surrounding the film’s topic, the early history of activist organization Greenpeace and the resultant jump-starting of the environmental movement, mostly had to do with the incredible cast of characters drawn to participate in the various brazen and oftentimes outlandish acts of civil disobedience associated with the group through the years.

It was the incongruous nature of our species, of course, that so captured Rothwell in its “widening gyre.” How humans who can agree so passionately on the plummeting state of the environment can disagree equally as passionately about how best to get it back on track definitely spawns a comedic component within the narrow-browed seriousness of its commitment.

Screening as part of the World Cinema Documentary Competition, Rothwell’s film unfolds chronologically, in that it opens with the somewhat untidy conglomeration that first showed up in Vancouver, B.C., to protest a 1971 U.S. atomic test on the Alaskan island of Amchitka and continues from there.

One of the crew who set sail aboard the “Phyllis Cormack,” the somewhat rusty old fishing vessel purchased through proceeds from a hastily thrown-together benefit concert featuring Joni Mitchell, James Taylor, Phil Ochs, Chilliwack and others, referred to the motley bunch of Quakers, pacifists, ecologists, journalists, engineers, scientists, and “hippies” as “a seagoing gang of ecological bikers”.

Rothwell couldn’t have assembled a more suitable cast of characters for his film if he tried. This wasn’t a warm and fuzzy, touchy-feely, bunch of tree huggers that answered the call of their “wild.” That ethic would come later as the movement evolved.

These folks were going to STOP people from harming their planet and they didn’t all necessarily agree on exactly which means to that end they could individually sign off. In fact, it’s from the conflicts among the rainbow-warriors-in-question, through some astounding archival footage, that the film draws most of its ethical, not to mention, engrossing footprint.

With the nuclear protest resulting in the U.S. abandoning Amchitka as a nuclear testing ground, their confidence grew into a “Save the Whales” campaign, an encounter with those harvesting baby seal skins in the Maritime provinces, and, among other battles, fights against the dumping of radioactive waste at sea.

Greenpeace co-founder Bob Hunter’s rather succinct rationale for their selected incursions into the world’s comfort zones more or less laid out the group’s motivation. “If we wait for the meek to inherit the earth, there won’t be anything left to inherit.”

To Hunter, a journalist by trade, these confrontations were “mind bombs” to be trolled astern in order to get the attention of mass media, which, he knew, in the eyes of the world, could turn a bunch of ragtag, yet highly educated and motivated, environmental advocates into media darlings and martyrs of the cause.

This is especially true when there’s footage of whaling vessels, blood gushing from their decks, attempting to ram into the Greenpeace ship or strike one of their inflatable “Zodiak” watercraft with harpoons. Not to mention film of the nucleus of the anti-baby-seals-harvest protesters singled out at a community meeting of those who make their living in the trade.

Paul Watson, the founder of the Sea Shepherd Conservation Society and whom one might recall from the final pages of Edward Abbey’s novel “Hayduke Lives!” cuts a wide and not-often-harmonious swath through the early years of Greenpeace history, making for one of the more complex characters in recent documentary filmdom. Myself, I felt kind of drawn to his “excesses.”

For anyone interested in the germination of the worldwide environmental movement, “How To Change The World” should be assigned viewing. As filmmaker Jerry Rothwell puts it: “Like everyone else on the outside, other than by (television) news stories, I never knew how they (Greenpeace) got together. In this case it (life) was certainly stranger than fiction.”

Jerry Rothwell’s “How to Change the World” is an entry in the World Cinema Documentary Competition at this year’s Sundance Film Festival. It premieres Thursday, Jan. 22, at 8:30 p.m. at the MARC Theatre. Additional screenings are Friday, Jan. 23, at 6 p.m. at Sundance Mountain Resort, Saturday, Jan. 24, at 3 p.m. at Redstone Cinema 7, Monday, Sept. 26, at 6 p.m. at the Tower Theatre, Thursday, Jan. 29, at 8:30 p.m. at the Library Center Theatre, and Friday, Jan. 30, at 3 p.m. at the Temple Theatre.