Russia's invasion of Ukraine and the subsequent rise in oil prices have thrown Europe's energy security into stark relief, particularly now that the European Union agreed to ban 90% of Russian oil imports by the end of the year.

"Europe's big lesson out of this is that they want to be energy independent," U.S. Special Presidential Envoy for Climate John Kerry said in an interview with Yahoo Finance Editor-in-Chief Andy Serwer at the World Economic Forum (video above). "They're going to move far more rapidly to get off of Russian gas to separate themselves and to deploy the renewable base of their grid so that they can be free from the emissions and from petrol dictators who weaponize energy."

Before the agreement on Tuesday, Europe had been split on the embargo. The bloc reached an agreement by carving out an exemption for a pipeline that serves Hungary, the Czech Republic, and Slovakia.

"We must become independent from Russian oil, coal and gas," European Commission President Ursula von der Leyen said in a March statement. "We simply cannot rely on a supplier who explicitly threatens us. We need to act now to mitigate the impact of rising energy prices, diversify our gas supply for next winter and accelerate the clean energy transition."

Earlier this month, Germany and Italy were given permission from Brussels to circumvent sanctions by accepting energy payments in rubles, a move that helps Russia's heavily-sanctioned economy.

Poland, Bulgaria, and Finland have refused to convert payments to rubles. Gazprom, Russia's state-owned energy corporation, retaliated by cutting off gas supplies to Finland, Bulgaria, and Poland as well as cutting off services to companies in the Netherlands and Denmark. Finland had received nearly all of its gas supply from Russia — however, that supply comprised only about 5% of its energy consumption.

Weaning off Russian gas amid 'the problem of the climate crisis'

Given Europe's plan to wean itself off Russian gas imports, the question remains how it will replace that fuel supply.

EU leadership maintains that renewable energy investment is the "most important pillar" of its energy strategy, though the REPowerEU plan also details how the EU will seek natural gas elsewhere — EU gas deliveries from suppliers outside of Russia doubled in Q1 year over year — and increase its gas storage capacity. Furthermore, the EU expects to extend the use of coal facilities despite carbon neutrality goals.

As of 2020, 35% of Europe's energy comes from petroleum products like oil, 24% comes from natural gas, and 17% comes from renewables. The combination of energy sources Europe chooses going forward has significant consequences for global warming pathways.

"I think the end product could be very salutary," said Kerry, who served as Secretary of State during the Obama administration. "But you've got to avoid building out major long-term infrastructure that... doesn't capture emissions and deal with the problem of the climate crisis."

Kerry also warned that the conflict in Ukraine could "become an excuse" for some who wish to keep the status quo in energy markets rather than transition to greener alternatives. As the Saudi Energy Minister said after the invasion caused oil prices to skyrocket: “Who is talking about climate change now?”

'Nuclear will be part of that mix'

Before the Russia-Ukraine war, the European Union was the largest buyer of Russian energy, importing 40% of its natural gas and about 25% of its oil from Russia.

A number of factors played into Russia's energy dominance in the region, particularly for natural gas.

At one point, European nations like the Netherlands relied on their own gas production in the North Sea. When those reserves began producing less in the 1960s and 1970s, Europe shifted to importing Russian gas due to the country's large gas supply and its proximity.

The shift to natural gas intensified when nations like Germany moved to reduce their dependence on coal and nuclear energy. Europe began building out renewable energy infrastructure at this time, though not sufficiently enough to satisfy gas and oil demand.

And then Russia invaded Ukraine, upending those policies.

Germany canceled its certification of the $11 billion Nord Stream 2 pipeline, effectively ended a project that would have increased the flow of gas from Russia to Germany. Lithuania then cut off its Russian natural gas supply entirely, becoming the first EU member state to do so.

Luckily for Europe, some countries had been building out renewable capacity in an effort to lower carbon emissions and reestablish more control over their energy supply even while depending on Russia. And while the European Union overshot its 2020 target of achieving 20% of energy consumed from renewables, its energy transition is still lagging climate targets needed to curb global warming.

According to Kerry, Europe's energy picture going forward will include solar, wind, geothermal, and nuclear.

"A lot of other countries have decided that they just can't get to net zero 2050 without the use of a zero emissions current technology capacity," Kerry said. "And so, yes, nuclear will be part of that mix."

Grace is an assistant editor for Yahoo Finance.

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