Many evangelical Christians believe that stewardship of the Earth and taking care of the poor and sick are core to their faith.

Yet roughly 8 in 10 voted for Donald Trump, who as president has proposed cutting the budget of the Environmental Protection Agency by 31 percent, the National Institutes of Health by 18.3 percent and isn’t sure if he wants the United States to participate in the Paris climate change accord.

That politics-science-faith disconnect is one of many threads running through the March for Science events to take place Saturday in more than 500 cities around the world, including San Francisco, San Jose and Livermore, with the main event in Washington, D.C. Organizers say 13,500 people have signed up to attend the San Francisco march and science fair, while an additional 17,000 have expressed interest in attending through social media channels.

The rallies are intended to be “political but not partisan,” said Kristen Ratan, the lead organizer for the San Francisco march. The goal of Saturday’s events is to highlight concerns that “science is not being supported,” said Ratan, who added that cuts to the NIH jeopardize “research on cancer, diabetes and childhood diseases.” If federal funding is cut, Ratan said, critical research could be lost.

“It is one of the alarm bells that are ringing,” she said.

When it comes to science, President Trump appears to be out of touch with many of his voters, evangelical or not.

While the president has referred to climate change as a “hoax” perpetrated by China, 49 percent of Trump voters think global warming is real, while 30 percent do not, according to a post-election survey of registered voters in November by Yale and George Mason universities. And nearly half of Trump voters said the U.S. should participate in international agreements to limit global warming, compared with 28 percent who said it should not, according to the study.

In November, there was another message that resonated even more loudly than science with evangelical voters.

“Most evangelicals voted for Trump for one reason and one reason only: The promise to put someone on the Supreme Court who would overturn Roe v. Wade,” said the Rev. Mitch Hescox, president of the Evangelical Environmental Network — which claims 80 organizations and 3 million pro-life Christians as members. A contingent from the organization will march in Washington on Saturday behind the banner: “Climate science: It’s a matter of life.”

For years, Hescox said he has been trying to rally support among evangelicals “to see pro-life is not just about abortion. It’s about all of life.” Like how working to improve air quality in a poor neighborhood would improve the health of children and the unborn there, he said.

But often, he said, faith community members don’t connect with the way that progressives try to explain climate change concerns — worrying about melting polar ice caps doesn’t resonate with many conservative evangelical voters, he said.

His credo is that being “pro-climate and pro-life is the same message. It’s the same value,” Hescox said. “Because climate change is the greatest threat to human life in the whole world.”

One challenge in bridging that political-science disconnect is that many evangelical Christians “don’t equate their political life with their religious life,” said Tim Ritchie, president and CEO of the Tech Museum of Innovation in San Jose. He will speak at the March for Science Silicon Valley as an expression of his Christian faith.

“For some reason, oddly, they don’t believe that when it comes to challenges like a pandemic or a cancer research that we can’t do it alone,” Ritchie said. “We actually need public support for science as part of our command to love our neighbor.”

Ritchie, who grew up in Kentucky, attended school in North Carolina and lived in Alabama for 17 years, said many of “my red state friends” are smart people who know the value of science. “I’m trying to get my friends, especially my friends in the red states, to be their best selves and be reasonable.”

Others are trying to bridge the divide in the heart of the very politically blue Bay Area.

On Wednesday night, on the second floor of a storefront in Albany, 19 members of the Solano Community Church listened to fellow congregant Dave Kurz give a presentation on “Dominion and Stewardship.” The informal talk was one in a series the congregation has offered in recent months on how spirituality and science mix.

Compared to evangelical congregations elsewhere, this group may be a bit more politically moderate, but members say their church includes Trump voters and that there is a wide diversity of opinion among them.

Like Kurz, a doctoral environmental science student at UC Berkeley, many in the room work in science or engineering fields and frequently wrestle with the question of how faith and empirical evidence interact. Kurz rolled through a 30-minute PowerPoint presentation that deftly weaved hard scientific studies with biblical passages and largely steered clear of partisan politics. The word “Trump” was not mentioned.

Instead, he explained how climate change has affected corn yields in South America and Africa.

“Caring about climate change is really caring about the poor — the weak and vulnerable that God has the heart for are really suffering,” Kurz said.

The “sad and frustrating” part, Kurz said, is that he knows many evangelicals who may acknowledge the science of climate change but don’t speak out about it because the political climate demands that they “kind of have to buy this whole political umbrella” encompassing everything conservative.

“I’m not trying to tell Christians how to vote,” Kurz said. “But something that has to do with science should be about science, not part of some larger package.”

Solano’s pastor, Andrew Hoffman, who attended Wednesday’s meeting, said: “It’s a question of thinking carefully. How do you wade into hot-button issues in a way that creates more light than heat? That is a slow process.”

Joe Garofoli is The San Francisco Chronicle’s senior political writer. Email: jgarofoli@sfchronicle.com Twitter: @joegarofoli