In the United States, where a climate change denier made his way to the White House partly on the strength of his appeal to white evangelical voters, many see Christianity and climate science as opposing forces.

But Bill McKibben, one of the nation’s most important environmental activists, is a walking rebuke of that notion.

Raised on a steady diet of C.S. Lewis and teachings from the Presbyterian and Congregationalist churches, McKibben volunteers to teach Sunday school at the Methodist church in Vermont he attends now. He also wrote the first book on climate change aimed at a general audience. “The End of Nature,” published in 1989, became a bestseller translated into 24 languages that is now considered a classic of environmental literature.

Even though he wasn’t writing for a Christian publishing house, the combination of his faith and climate-centric writing was unusual during a time when there was “no religious environmentalism at all,” he said in a recent interview.

“Among liberal churches, I think environmentalism was viewed as a luxury you would get to after you’d dealt with poverty and war, and among conservative churches, it was viewed as a way station on the road to paganism,” McKibben said with a laugh.

Now he expects people of faith to join protests like the climate strike happening around the world on Friday, which he sees as a movement-building moment with the potential to shift the zeitgeist. Ultimately, these community actions make a bigger impact than individual lifestyle choices, he said.

“The gospel call to love one's neighbor is, in our time and place, most fully a call to do something about climate change,” he said, “because at the moment, we're drowning our neighbors, sickening our neighbors, making it impossible for our neighbors to grow food.”

Since his 1989 book, McKibben has written over a dozen more books on the environment, including one that relies heavily on the biblical narrative of Job. He also started, a grass-roots organization aimed at combating the fossil fuel industry and its contributions to climate breakdown. He’s also become a professor at Middlebury College, been arrested multiple times for civil disobedience, earned a host of fellowships and awards, and watched as more religious people assume leadership in the fight against anthropogenic climate change.

“It's been wonderful to watch that happen,” McKibben said. “Ministers [are] out front in their collars, making it clear what a moral issue this is. … This is the dominant scientific and economic issue of our century. It's also the dominant theological issue.”

He’s quick to credit scholars such as Mary Evelyn Tucker and John Grim, who established interfaith, environment-centric theological conferences at Harvard in the 1990s, for their role in pushing the conversation forward in religious circles. At a decade later, he witnessed churches becoming some of the earliest organizations to divest from fossil fuels.

In short: McKibben watched the age of religionless environmentalism end. The most important document about climate change in the past decade, he said, was Pope Francis’s 2015 encyclical on the environment, “Laudato Si.” And, he argued, “at this point, faith communities are very much in the lead in the work that’s going on.”

As for the evangelicals who have given American Christians a reputation for being climate change deniers? McKibben finds it useful to focus on how the warming planet impacts the poor, especially in the developing world. He said their habit of taking mission trips means they’ve usually had more in-person contact with the developing world than many of their fellow U.S. citizens.

Beyond that, though, he’s not hung up on deniers lining the pews.

“The polling data’s pretty clear: Something like 70 percent of Americans really understand what’s going on” with climate change, McKibben says. “I always tell young people, ‘Don’t bother destroying Thanksgiving dinner fighting with your crazy uncle.’ The job instead is to take some part of that 70 percent and get them really engaged in this fight.”

McKibben points to a few key ways religious leaders and communities can energize people around climate issues, even without sermons full of science or policy debates. Leaders, he said, should underscore the connections between climate change and many of the other problems their communities are committed to, like the concept of caring for the vulnerable. McKibben highlights the immigration crisis, noting the way a warming planet will contribute to increasingly harrowing weather events that drive refugee migration.

McKibben also noted there’s an argument in many religious texts in favor of taking care of the planet and its nonhuman inhabitants, based simply on the idea that they were all made by God. From McKibben’s perspective, the story of Noah is about a radical environmentalist who went to great lengths to save a breeding pair of every kind of animal.

“That should make Jews and Christians think long and hard about the fact that we're about to enter the sixth great extinction in the planet's history,” he said.

McKibben is under no illusions that humans can completely undo the damage we’ve already done, and cheeriness that underestimates the ways climate breakdown is starting to bludgeon the planet isn’t what he recommends. He’s confident that societies will eventually move away from the fossil fuels destroying our atmosphere, but the problem is that “the world may be fundamentally broken by the time we get there.”

Knowing that, he says, churches should look to be a source of sanctuary to those hardest hit.

“Even if we do everything right from this point on, there are an awful lot of people who are going to be afflicted and need to be comforted,” he says. “That means taking in refugees, it means doing the relief efforts.”

In the opening of his most recent book, “Falter,” McKibben writes that “a writer doesn’t owe a reader hope — the only obligation is honesty.” But his posture in the world, which has been marked by a dogged commitment to his message over the course of decades, is a reminder of something religious communities can offer in the fight against climate breakdown.

McKibben might not call it hope, but whatever it is, it keeps him fighting for what’s right in the face of overwhelming odds.

“In this case, religious people have an advantage over everybody else,” he says. “People of faith are allowed to believe in a way that physicists have a hard time believing, that if we do everything we possibly can, there’s some chance the world meets us halfway.”

Whitney Bauck is an associate editor at, where she reports on the environmental and human rights impacts of the fashion industry. (She also occasionally writes about monks who knit and celebrity pastors with expensive taste.) Find her on most social media platforms as @unwrinkling.