Gov. Jerry Brown held up California as a leader in the fight against climate change, renewing a pledge Wednesday with representatives of the Netherlands to continue cutting carbon emissions and investing in clean technology.

The commitment, made at a climate discussion in San Francisco between California and the European nation, was largely ceremonial, but it underscored the state’s effort to charge forward on global warming where the federal government — under President Trump — has fallen short.

Brown reiterated criticism of Trump, who has called climate change a hoax. However, he also expressed optimism that the president would come around on the issue, in part because China and other world powers were forging ahead.

“I don’t think that President Trump will want to stay on the side while this climate story unfolds,” Brown said. “I’m cautiously optimistic that we are going to make progress, not as fast as I would like but not as disastrous as we were thinking just a few months ago.”

Brown was alongside the Netherlands’ minister for the environment, Sharon Dijksma, in keynoting Wednesday’s climate conference at the Golden Gate Club in the Presidio.

Alongside California, the Netherlands was one of the earliest to join the Under 2 Coalition, an agreement among nations and states to try to limit temperature rise by reducing carbon pollution. It was also the first European nation to welcome a Tesla on its roads, according to the envoy.

California and the Dutch have since collaborated in supporting climate initiatives like clean tech, including zero-emissions cars, for which they reaffirmed their backing on Wednesday. The governor said he expects to do more to get environmentally friendly electric vehicles on the state’s roads.

Wednesday’s session comes a week before Brown heads to China to attend an international climate summit, where the governor is expected to expand California’s collaboration with foreign governments.

The state has led the nation and the world in its policies to limit greenhouse gases from power plants and automobiles, and has supported investment in renewable energy and other pollution-curbing technology.

“We have to make the tough decisions, new laws, new regulations, new investments, new spending on a whole wide variety of areas,” Brown said. “We’ve done a lot in California, but we have a long way to go.”

Concerns about Trump’s plans to roll back environmental rules and potentially allow industry to make an end run on California’s governance prompted state leaders to hire former U.S. Attorney General Eric Holder to stand up to Washington.

Brown, though, hopes the state can work positively with Trump, and said Wednesday that he was encouraged by the administration’s recent decision to fund the electrification of Caltrain.

With Trump visiting the Vatican this week on his first overseas trip as president, Brown also said it was good to see the president meet with Pope Francis, who is a strong advocate in the fight against climate change. The Vatican’s secretary of state urged Trump not to retreat from the landmark Paris climate accord.

“Don’t underestimate the power of the Holy Father,” Brown said. “I think that has an effect.”

Kurtis Alexander is a San Francisco Chronicle staff writer. Email: kalexander@sfchronicle.com Twitter: @kurtisalexander