A pair of Democratic lawmakers on Friday accused the largest oil companies in the United States of “greenwashing” their public image and not doing enough to decarbonize fast enough to meet climate change targets.

Carolyn B. Maloney, chair of the U.S. House of Representatives’ main investigative committee, the Committee on Oversight and Reform, and Ro Khanna, a member of the same committee and the chair of the Oversight Environmental Subcommittee, sent a 31-page letter on Friday to the rest of the members of the committee with the latest findings from their ongoing investigation into the fossil fuel industry.

Burning fossil fuels releases carbon dioxide into the atmosphere and causes global warming. The Oversight Committee began its investigation into what it calls a “climate disinformation” campaign in Sept. 2021 and held a hearing with top executives from oil and gas giants on Oct. 28 of that year.

The letter is the latest installment in the committee’s bid to demonstrate that oil companies are not trying to reduce their CO2 emissions quickly enough, while obscuring their lack of participation.

“These documents demonstrate how the fossil fuel industry ‘greenwashed’ its public image with promises and actions that oil and gas executives knew would not meaningfully reduce emissions, even as the industry moved aggressively to lock in continued fossil fuel production for decades to come — actions that could doom global efforts to prevent catastrophic climate change,” the letter reads.

These efforts are particularly offensive, Maloney and Khanna said, because of the amount of money the biggest oil companies are making right now.

“The fossil fuel industry’s failure to make meaningful investments in a long-term transition to cleaner energy is particularly outrageous in light of the enormous profits these companies are raking in at the expense of consumers — including nearly $100 billion in combined profits for Exxon, Chevron, Shell, and BP in just the last two quarters,” the letter reads.

The letter also details ways in which the oil companies have made insufficient efforts to decarbonize their businesses, and points to internal documents that show how the companies are continuing to invest in fossil fuel production and increase output.

“Each of the companies has publicly pledged to reach ‘net zero’ greenhouse gas emissions by 2050,” the letter reads. “However, experts have found that not one of the net zero pledges from BP, Shell, Exxon, or Chevron are aligned with the pace and scope of cuts necessary to meet the goals of the Paris Agreement and avert catastrophic climate change.”

The letter also points to documents that show how the industry is pushing natural gas as a long-term climate solution.

“In 2021, natural gas contributed to 34% of U.S. energy-related emissions and 22% of emissions globally,” the letter reads. “Documents obtained by the Committee show fossil fuel companies and lobbying groups seek to publicly position natural gas as a clean source of energy and part of the transition to renewables, even as the industry is privately planning for expanded natural gas production over the long term.” 

Burning natural gas results in fewer greenhouse gas emissions than burning coal or other kinds of fossil fuels for the same amount of energy, according to the U.S. Energy Information Administration, but it still releases greenhouse gas emissions. Burning natural gas produces about 117 pounds of carbon dioxide per million British thermal units (a measure of heat). That’s compared with 200 pounds for coal and 160 pounds for fuel oil.

Equally critically, the production of natural gas results in leaks of methane all throughout the production process and methane is a greenhouse gas, too. It’s a different greenhouse gas than carbon dioxide, but still contributes to global warming.

“Our industry is focused on continuing to produce affordable, reliable energy while tackling the climate challenge, and any allegations to the contrary are false.  The U.S. natural gas and oil industry has contributed to the significant progress the U.S. has made in reducing America’s CO2 emissions to near generational lows with the increased use of natural gas,” Megan Bloomgren, senior vice president of the American Petroleum Institute, told CNBC.

The API also pointed to the industry’s focus on developing carbon capture, utilization and storage (CCUS) and hydrogen technologies.

“We are poised to be a leader in the next generation of low carbon technologies, including CCUS and Hydrogen — technologies widely recognized to be critical to meet the world’s emissions reduction targets.  API will continue to work with policymakers on both sides of the aisle for policies that support industry innovation and further the progress we’ve made on emissions reductions,” Bloomgren said.

Chevron declined to comment. In June, Chevron CEO Mike Wirth wrote an open letter to President Joe Biden saying that the oil company had produced the highest volume of oil and gas in its 143-year history in 2021. And Wirth pointed out that carbon emissions associated with segments of its oil and gas production was lower than global averages.

“At roughly 15 kg of CO2-equivalent per barrel, Chevron’s Permian Basin carbon intensity is some two-thirds lower than the global industry average. U.S. Gulf of Mexico production has carbon intensity just a fraction of the global industry average,” Wirth wrote. In the letter Wirth also said the oil company was investing $10 billion to reduce greenhouse gas emissions, scale carbon capture and hydrogen technologies, and grow its renewable liquid fuels production. 

BP did not immediately respond to an email seeking comment.