Climate change is a top priority for California’s most liberal Democratic voters, a choice reflected in the presidential candidates they back, according to a poll by UC Berkeley’s Institute of Governmental Studies.

Among voters likely to cast ballots in the March 3 Democratic primary who identified themselves as very liberal, 57% said climate change should be the leading priority for the next president, compared with 37% for self-styled moderates.

White non-Hispanics, voters younger than 30 and college graduates all put climate change on top, said Mark DiCamillo, the poll’s director.

“That’s the liberal wing of the Democratic Party, and they are the polar opposite of President Trump’s supporters,” he said. “And about two-thirds of California’s likely Democratic voters say they are at least somewhat liberal.”

The poll asked voters to chose from four issues: climate change, health care reform, immigration reform and criminal justice reform. Climate change was the top choice of 47%, followed by health care at 32%, immigration at 14% and criminal justice at 3%.

Backers of Vermont Sen. Bernie Sanders and Massachusetts Sen. Elizabeth Warren, who ran one-two in the institute’s poll of Democratic contenders in the state, put reducing emissions and greenhouse gases on top of their list of concerns. For Warren backers, the total was 62%, and for Sanders supporters it was 44%. For backers of South Bend, Ind., Mayor Pete Buttigieg, fourth in the poll, it was 53%.

Health care reform was the main concern for backers of former Vice President Joe Biden, with 38% ranking it the top priority. One-fourth of Biden’s supporters wanted a path for citizenship for undocumented residents to be the top priority for the next president, far more than any of the other contenders.

The strong support for dealing with climate change is no surprise, DiCamillo said.

“There’s always been bipartisan support for protecting the environment because we have so much environment to protect,” he said. “But the series of natural disasters and Trump’s stands (on the environment) have brought it to the front.”

But that consensus isn’t there with health care. While 80% of those polled believe health care reform should be one of the leading concerns for the next president, California Democrats split on what that reform should be.

The Medicare for All plan favored by Sanders, which includes eliminating all private health insurance in favor of a single government-run program, was preferred by 37% of the voters surveyed. By contrast, 57% backed a plan that would modify the existing system by allowing people to choose a Medicare-style program, but also allow them to keep their existing private insurance if they preferred. That’s a direction favored by Biden and Buttigieg.

Warren originally supported Sanders’ proposal, but in recent weeks has stepped away from his government-run plan, saying that as president she would move toward a Medicare for All plan but not immediately. The poll found that more than half her backers favored modifying the current system over Sanders’ Medicare for All proposal.

While around a third of Sanders, Biden and Buttigieg supporters in California believe health care reform is the top priority, they have very different ideas of what that reform should be.

Nearly two-thirds of the pro-Sanders voters want to see Medicare for All as the law of the land, while 72% of Biden’s voters and 80% of Buttigieg supporters prefer to modify the Affordable Care Act.

The poll was based on an online survey of 3,482 registered voters, including 1,694 who are considered likely voters in the March 3 Democratic primary. Unlike California Republicans, Democrats allow voters registering as no political party to cast ballots in their primary.

The survey was taken from Nov. 21-27 and has a margin of error of plus or minus four percentage points.

John Wildermuth is a San Francisco Chronicle staff writer. Email: jwildermuth@sfchronicle.com Twitter: @jfwildermuth