Defying criticism from climate activists, Joseph R. Biden Jr. on Thursday attended a fund-raiser co-hosted by a founder of a liquefied natural gas-related company and defended his decision to do so, despite concerns from some environmentalists that he violated the intent of a pledge to forgo money from oil and gas executives.
It is the latest example of tension between Mr. Biden, the poll leader in the Democratic presidential primary, and energized activists who often reflect the mood of the party’s more liberal wing.
The fund-raiser on Thursday evening was co-hosted by Andrew Goldman, a former adviser to Mr. Biden and a co-founder of Western LNG, a company based in Houston that develops export facilities for liquefied natural gas.
Mr. Biden, like many of the presidential candidates, has signed a pledge saying that he would not take more than $200 in contributions from “S.E.C.-named executives of fossil fuel companies,” among others, and he had been pressed on his association with Mr. Goldman on Wednesday night in a climate-focused forum hosted by CNN.
“I just want to be very clear to everyone here: I am committed to not raising money from fossil fuel executives and I am not doing that tonight,” Mr. Biden, the former vice president, said on Thursday, according to a pool report of the fund-raiser. “Climate change presents an existential threat, and it is real.”
Officials with Mr. Biden’s campaign have said that Mr. Goldman is not involved in day-to-day operations of the company and that he does not sit on its board, though the company lists him on its website as a co-founder. A 2018 news release tied to the company also described Mr. Goldman as “a long-term investor in the liquefied natural gas sector.”
About two dozen activists from the Sunrise Movement and other environmental groups gathered outside the Majestic building, at 115 Central Park West, to protest the fund-raiser, offering chants like, “Hey hey, hey Joe, fracked gas has got to go.”
“Biden can’t expect to convince Americans that he’s a leader on climate if he’s also cozying up to fossil fuel power players,” said Laura Shindell, an organizer with Food and Water Action, an organization that seeks to ban fracking and prevent new permits and pipelines for it.
The protesters — boisterous, cheerful, sometimes dancing — arrived in numbers that were only a fraction of the crowd that had called for urgent action on climate change outside the site of the climate forum in Manhattan the day before. The relatively small turnout, organizers said, was because of the difficulty of determining the location of the fund-raiser on short notice.
But they said they aimed to continue face-to-face protests to urge candidates and donors to support tough action against greenhouse gas emissions.
“This is one of the most effective things we can do,” said Matthew Miles Goodrich, 26, a fund-raiser for the Sunrise Movement. “My generation is uniquely damaged by the policies that aren’t meeting the challenge of the climate crisis. We really want the candidates who aren’t measuring up to look us in the eye, at the faces of the people they’re condemning in some ways to climate disaster.”
The protest was unusual in the sedate area along Central Park, near the landmark Dakota building, where many of the city’s wealthy liberals, and some conservatives, live in spacious apartments. Bemused passers-by — dog walkers, people with baby strollers, teenagers coming home in private-school sports uniforms — stared at the protest. Some stopped to give their support.
“This is not a little mistake,” said Steven Jackman, 62, a retired computer network technician from Massapequa, N.Y. “Climate change is right now. Fracking is dangerous for the water in New York — people love New York water, it’s the purest — and it’s dangerous all over the country.”
But, he added, it was not surprising that candidates would take money from the fossil fuel industry.
“You can’t expect them not to meet with these people — he needs their money,” Mr. Jackman said.
Mr. Biden, for his part, has released a sweeping plan to combat climate change that would end subsidies for fossil fuels and urges “action against fossil fuel companies and other polluters who put profit over people and knowingly harm our environment.”
He discussed the plan at the fund-raiser on Thursday and also appeared to set up a veiled contrast with some of his opponents like Senator Elizabeth Warren of Massachusetts, who talks frequently about her long list of policy plans.
“You have to have plans,” he said, “but you have to be able to execute those plans.”