On Oct. 9, 2016, Ward left for northwestern Washington, Higgins for Montana, Klapstein and Johnston for Minnesota and Foster for North Dakota. They agreed that their actions would be nonviolent and that they would willingly accept the consequences in court. All five have faced or are facing trials in the states where their actions took place, and in each, they have sought to use the “necessity defense” — to argue that they broke the law because they had exhausted all legal means to reduce or eliminate a clear and present danger, namely the threat of climate change. The necessity defense, traditionally applied to crimes committed to head off immediate physical threats, has been permitted only rarely in civil-disobedience cases, and it has almost never succeeded. But for the Valve Turners, its articulation is a deliberate extension of their campaign, a way to publicly express the urgency they feel. “It’s both practical and political,” says Lauren Regan, the executive director of the Civil Liberties Defense Center in Eugene, Ore., and the lead attorney in Ward’s case. “Talking about this as a necessity — that really pushes the conversation in a direction the movement wants it to go.”

The Valve Turners see their actions as complementary to the rest of the climate movement, as adding an offense to a movement that has so far played mostly defense — as it did during the mass protests against the proposed Dakota Access Pipeline in 2016 and early 2017, which were led by the Standing Rock Sioux and other tribes. Foster says: “I’d participated in all these different protests, but how much of the poison had I actually stopped? That I had a chance to take a major action against the existing flow — God, finally.”

But the Valve Turners’ tactics are not popular within the environmental movement as a whole and remain controversial even within the climate movement. While the national leadership of 350.org offered its support to the Valve Turners after their arrests, the response from mainstream environmental groups was subdued; for some, the shut-offs were reminiscent of the anonymous vandalism carried out by groups like Earth First! and the Earth Liberation Front beginning in the 1980s, which enabled opponents to demonize environmentalists as domestic terrorists.

DeChristopher, who went on to study divinity at Harvard, has worked with several of the Valve Turners through the New England-based Climate Disobedience Center, which provides strategic support to climate activists practicing civil disobedience. He says their willingness to assume responsibility, and to publicly explain their actions, distinguishes their strategy from that of anonymous saboteurs. “If you do something and then run away, that gives your opponents a huge opportunity to come in and say, ‘Let me tell you who these people are and why we should go after them,’ ” he says. “If you stand your ground and tell your story, that puts a face on it, and it can have an entirely different effect.”

This theory was tested when Ward, whose case was the first to go to trial, appeared in court in the small city of Mount Vernon, in far northwestern Washington State, on a cold, bright January morning last year. The judge, Michael Rickert, did not allow Ward to use a necessity defense, ruling that Ward had not exhausted his legal options. Ward was charged with both burglary and sabotage — which, in Washington, is defined in part as willful interference with a commercial enterprise — and as Rickert dryly pointed out, the case was “not exactly a whodunit.” The jury even watched a video of Ward cutting the chain that secured the emergency valve of Kinder Morgan’s Trans Mountain pipeline. But after nearly six hours of sometimes heated deliberation, the jurors announced that they could not come to a decision on either charge. They told me that all were in favor of conviction except for one, who maintained that Ward’s primary intent was not to break the law but to make a point about climate change.

The judge declared a mistrial based on the hung jury, and Ward was tried again five months later, in June. This time, he was convicted of burglary, but once again the jurors could not reach a decision on the sabotage charge. The second jury was even more divided than the first: a retired nurse who voted against conviction on the sabotage charge described Ward as a “hero,” while the presiding juror, Donald Munro, voted for conviction on both counts, calling Ward a “jerk” who “did it to get attention.”