Western oil companies’ plans to exit Russia may have some unintentional consequences on global efforts to shift to cleaner forms of energy.

Under political pressure to withdraw investment from Russia following its invasion of Ukraine, big oil-and-gas companies are announcing plans to sell assets and cut ties with the Kremlin, part of a broader effort to isolate the Russian economy.

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Western oil companies’ plans to exit Russia may have some unintentional consequences on global efforts to shift to cleaner forms of energy.

Under political pressure to withdraw investment from Russia following its invasion of Ukraine, big oil-and-gas companies are announcing plans to sell assets and cut ties with the Kremlin, part of a broader effort to isolate the Russian economy.

It remains unclear what the terms of any divestments might be, and the end results are hard to predict. Here are five ways the rush to the exit could affect oil companies’ climate plans and the broader push to cleaner energy.

Funding the transition

Russia supplies around 27% of Europe’s oil and 41% of its gas. By pushing prices to new highs and prompting European leaders to seek energy independence from Moscow, the war in Ukraine could create fresh impetus in efforts to transition to cleaner fuels.

Shell PLC and TotalEnergies SE are among European companies that may see the crisis as an opportunity to expand their low-carbon investments, said Michael Grubb, a professor of energy and climate change at University College London.

“I don’t see Shell going backward—I expect the crisis to accelerate their investment into renewables and electricity, including electric-vehicle infrastructure,” he said. “Total may react in a similar way.”

Shell declined to comment. TotalEnergies didn’t respond to a request for comment.

TotalEnergies, which is heavily exposed to Russian natural gas, has said that it is considering its future in Russia and won’t make further investments, but it has not yet said that it would divest. In 2020, Russia accounted for 24% of the company’s proven fossil-fuel reserves.

Doubling down

However, withdrawal from Russia won’t necessarily lead to strategic reappraisals by companies. For a start, a costly pullout could make companies less inclined to direct money toward less-lucrative renewable or low-carbon projects—even at a time when they are otherwise flush with cash.

The Russian assets are “not worth as much as they were even two weeks ago,” said Samantha Gross, director of the energy security and climate initiative at research group Brookings Institution. “Divestment is a hit to the balance sheet of every one of these companies.”

Shell will take an approximately $3 billion loss from its decision to exit all joint ventures with Russia’s state-controlled Gazprom.

BP faces a potential loss of as much as $25 billion from the exit of a nearly 20% stake in state-controlled oil company Rosneft.

Espen Erlingsen, head of upstream research at Rystad Energy, said energy companies won’t save money from the Russian exits, but they might free up resources that could go to other oil-and-gas projects. For BP, they could go toward projects in Africa and the U.S., while Exxon Mobil Corp., which is discontinuing its oil-field operations on Russia’s Sakhalin Island and plans to sell them and not invest further in the country, could plow the resources into Guyana and the U.S. Permian Basin, he said. Exxon valued its Russian assets at around $4 billion at the end of last year.

Mr. Grubb at UCL said, “if history is a judge, Exxon seems most likely to react in the opposite direction: building further their investment in fossil-fuel reserves, maybe moving further into [liquefied natural gas] outside of the Russian orbit.”

BP and Exxon declined to comment.

Leaking talent

The departure of Western oil companies from Russia will have nonfinancial impacts. Andrew Logan, senior director for oil and gas at sustainable-finance nonprofit Ceres, said companies from outside Russia have helped develop some of the country’s most technically challenging oil-and-gas assets.

The withdrawal of this know-how from the country may affect the progress of oil-and-gas projects in challenging environments, such as the offshore Arctic, which are pivotal to the expansion of Russia’s energy industry, he said. In theory, the disruption could be a long-term headwind, he added.

“Without the technical expertise of the Western majors, Russian supply will be constrained, likely keeping oil-and-gas prices high and providing a strong economic incentive for the switch to low-carbon alternatives,” Mr. Logan said.

New emissions risks

On the other hand, Mr. Logan said the loss of expertise in Russia could undermine efforts to limit emissions of methane, a potent greenhouse gas that leaks from fossil-fuel infrastructure. Russia is the world’s largest emitter of methane in oil-and-gas production, according to the International Energy Agency.

“There is a real risk that the Russian oil industry could unleash a torrent of methane that threatens global progress in bringing down greenhouse-gas emissions,” Mr. Logan said.

That reflects a broader risk—that the transfer of oil-and-gas assets to operators with less-ambitious climate plans, or those who are subject to less scrutiny, could push up emissions.

Ms. Gross at Brookings said Exxon had some incentive to reduce emissions at the Sakhalin 1 oil-and-gas project in the Russian Far East. It was the operator of the asset, as well as a minority owner, and the company’s pledge to reach net-zero emissions by 2050 covers assets that it operates. It is only a voluntary pledge, but the next owner might not be subject to that pressure, Ms. Gross added.

“This is an example where the new [owners] might have different emissions-reduction plans,” Ms. Gross said.

Little impact on climate targets

In general, however, experts said the exits won’t have a huge impact on companies’ climate-change plans, because their Russian operations weren’t always fully factored into their carbon accounting and didn’t account for a huge portion of their business.

The biggest sale would be BP’s nearly 20% stake in Kremlin-controlled Rosneft, worth around $14 billion at the end of last year. But BP never reported emissions arising from its stake in Rosneft or included them in its emission targets, a BP spokesperson said. Shell, however, did include its Russian stakes in its net-zero plan.

“The impact on the sustainability strategies for these companies will be limited,” Rystad Energy’s Mr. Erlingsen said. Still, he said BP’s gas production now won’t grow at the rate that was previously expected, changing the company’s sustainability profile.

Write to Dieter Holger at dieter.holger@wsj.com and Giulia Petroni at giulia.petroni@wsj.com