Last summer the European Union unveiled “Fit for 55,” a radical plan to move away from carbon-based energy, which envisions deep cuts in greenhouse gas emissions to meet a goal of reaching net-zero by midcentury. But Russian President Vladimir Putin’s invasion of Ukraine has forced several countries to backpedal on decarbonization, at least in the short term, to compensate for cuts in fuel supplies from Russia.

Since Russian troops rolled across the Ukrainian border on Feb. 24, European countries have started to burn more coal, plan new liquefied natural gas terminals, and extend the region’s network of gas pipelines. “I understand some governments are having to make difficult decisions to ensure energy supplies for their citizens,” says Fatih Birol, executive director at the International Energy Agency, which just last year called for an end to new oil and gas projects. “The current strains on energy markets are painful for us all.”

The climate plan announced on July 14, 2021, by the European Commission proposed tightening its existing cap-and-trade system for carbon emission permits, ramping up renewable power, and phasing out cars with internal combustion engines to slash emissions by 55% by 2030 from 1990 levels. The war in Ukraine has highlighted the degree to which those ambitions relied on gas piped from Russia to keep the lights on and factories humming while awaiting a payoff from hundreds of billions of euros in planned investment in renewables, electric cars, and technologies to cut emissions from heavy industry.

The region relies on Russia for about 40% of its gas and a third of its oil. With Putin weaponizing deliveries of the fuels, the EU is backing investment in infrastructure such as LNG production anyplace other than Russia and facilities to import it to the region. And it’s increasingly clear that larger quantities of coal will have to serve as a significant backup, which, until recently, was viewed as unnecessary and dangerous. Since February, carbon emissions from coal have jumped more than 6% from 2019 levels, according to researcher Kayrros SAS.

Russia has reduced gas shipments through every major pipeline to Europe this year, with exports at times falling to less than one-third of their March peak, the IEA reports. The curbs come despite a post-pandemic rebound in demand, with gas usage in Europe in 2021 hitting its highest level in a decade, British oil major BP Plc estimates.