(Reuters) — A Chevron Corp. attorney said in court Wednesday that the company supports scientific conclusions that humans are causing climate change, a response to a lawsuit that accuses five major energy producers of misleading the public for years about their role in global warming.

At a hearing in San Francisco federal court, Chevron attorney Theodore Boutrous also said that the scientific consensus about greenhouse gas emissions did not fully form until the past decade.

The cities of San Francisco and Oakland, California, sued Chevron, Exxon Mobil Corp., ConocoPhillips Co., Royal Dutch Shell P.L.C., and BP P.L.C. last year, seeking an abatement fund to help the cities address flooding they say is a result of climate change.

The companies argued in legal filings Tuesday that the case should be dismissed, partly because Congress has given regulatory agencies, not the courts, authority over the production and emission of fossil fuels.

The lawsuits, filed by Democrats, are part of a larger campaign to address climate change in the courts. Worldwide, there are almost 900 lawsuits on climate change in 25 countries, a U.N. study said last year.

U.S. District Judge William Alsup invited both sides to the hearing to describe their views on "the best science now available" on global warming and rising sea levels.

Since President Donald Trump took office 14 months ago, domestic climate change policy has been turned on its head. Republican Trump has pushed to increase production of fossil fuels and said he was withdrawing the U.S. from the Paris Agreement to reduce emissions, but Washington has not disengaged from it completely.

In court Wednesday, Mr. Boutrous said Chevron supports a 2013 report from the Intergovernmental Panel on Climate Change, which concluded it was "extremely likely" humans contribute to warming. However, Mr. Boutrous also said earlier IPCC reports were not as certain.

The judge asked Mr. Boutrous if the other four companies agreed with his presentation, and Mr. Boutrous said he was only speaking for Chevron.

No attorneys for the other four companies answered questions at the hearing, though all generally acknowledge the reality of climate change.

"I'm going to ask them at some point if they agree with everything you said," Judge Alsup said.

All five companies argued in court papers Tuesday that they should not be held liable for warming, which is caused by "billions" of parties and "complex environmental phenomena occurring worldwide over many decades."