Some of the world’s largest oil and gas companies have internally dismissed the need to swiftly move to renewable energy and cut planet-heating emissions, despite publicly portraying themselves as concerned about the climate crisis, a US House of Representatives committee has found.

Documents obtained from companies including Exxon, Shell, BP and Chevron show that the fossil fuel industry “has no real plans to clean up its act and is barreling ahead with plans to pump more dirty fuels for decades to come”, said Carolyn Maloney, the chair of the House oversight committee, which has investigated the sector for the past year.

The committee accused the oil firms of a “long-running greenwashing campaign” by committing to major new projects to extract and burn fossil fuels despite espousing their efforts to go green.

In reality, executives, the documents show, were derisive of the need to cut emissions, disparaged climate activists and worked to secure US government tax credits for carbon capture projects that would allow them to continue business as usual. Maloney, a Democrat, said that “these companies know their climate pledges are inadequate, but are prioritizing big oil’s record profits over the human costs of climate change”.

Ro Khanna, another Democrat who sits on the committee, said that the industry’s approach was one of “intimidation” towards critics, as part of a “cynical strategy” to avoid acting on the climate emergency. He added that the committee will pass on the documents to “other entities”, raising the possibility of charges laid by the US Department of Justice.

Khanna rejected allegations from Republicans that the Democrat-led committee had engaged in a sort of corporate witch-hunt. “The industry was the one out there continuing to make false statements about climate change and climate legislation,” he said. “Our goal is to get them to stop engaging in climate misinformation.”

Several of the company executives appeared before the committee, where they faced accusations their companies knew of the dangers of the climate crisis for decades, only to hide this from the public. Darren Woods, chief executive of Exxon, said last year that his company’s claims over climate change were “consistent with science” at the time.

“Oil and gas will continue to be necessary for the foreseeable future,” Woods added in his testimony to the committee. “We currently do not have the adequate alternative energy sources.”

Exxon, like most other large oil firms, has said it backs the Paris climate accords, where governments agreed to not allow the global temperature to rise 1.5C or more above pre-industrial times to help avoid worsening heatwaves, droughts, floods and other disastrous impacts.

Privately, however, these companies downplayed any need to scale down their fossil fuel activity and even to ramp it up, the committee found.

Internal documents from BP in 2017 show that the company intends to “significantly increase development in regions with oil potential” and to “focus primarily on projects in current basins that generate the highest rate of return”.

One BP executive subsequently asserted in an internal email that the company had “no obligation to minimize GHG [greenhouse gas] emissions”, while another admitted that any of its divestments of fossil fuels “may not directly lead to a reduction in absolute global emissions”.

Industry insiders communicated with Exxon consultants about doubts over the veracity of climate science, the documents show, while a strategy slide presented to the Chevron board by its chief executive, Mike Wirth, states that the company is to “continue to invest” in fossil fuels even if others retreat from oil and gas.

A Shell tweet posted in 2020 asking others what they could do to reduce emissions resulted in a torrent of ridicule from Twitter users. A communications executive for the company wrote privately that criticism that the tweet was “gaslighting” the public was “not totally without merit” and that the tweet was “pretty tone deaf”. He added: “We are, after all, in a tweet like this implying others need to sacrifice without focusing on ourselves.”

The UK-headquartered oil company also poured scorn on climate activists, with a communications specialist at the company emailing in 2019 that he wished “bedbugs” upon the Sunrise Movement, a youth-led US climate group.

Climate campaigners said the committee’s work showed that the fossil fuel industry was continuing to lie over global heating by pretending to act on the issue.

“The key revelation in this report is that big oil has no intention of actually following through on its climate commitments,” said Jamie Henn, director of Fossil Free Media.

“It isn’t transitioning to clean energy, it’s doubling down on methane gas, and it’s actively lobbying against renewable energy solutions. This is the big tobacco playbook all over again: pretend you care about a problem, but continue your deadly business as usual.”