Fossil fuels are everywhere. How quickly could we actually phase them out?

The world just lived through the hottest summer on record. Off the coast of Florida, the ocean temperature hit triple digits, killing coral reefs. Greece battled record wildfires. The extreme rain in Libya—where at least 11,000 people died in floods after dams collapsed—was made 50 times more likely by climate change. Phoenix spent 31 days above 110 degrees. Sea ice in Antarctica shrank to a record low, prompting what scientists called a “five-sigma event” that killed as many as 10,000 penguin chicks.

Despite the fact that extreme climate impacts are already obvious, most companies and countries are still making only incremental changes to cut emissions (or, in some cases, are moving backward, like in the U.K., where the prime minister now wants to slow down plans to move to electric vehicles). But what would be possible if we committed to actually moving fast on climate action beginning with the largest challenge: phasing out fossil fuels?

It’s an almost unimaginably massive task. Fossil fuels aren’t just used in the obvious places, like the billion-plus gas and diesel cars currently on the road, or thousands of power plants running on gas or coal. They’re in an endless list of products and materials, from sneakers and laundry detergent to the production of cement, steel, plastic, fertilizer, and virtually anything else made in a factory.

The United Nations is calling for the world to reach net zero by 2050, with at least an 80% cut in emissions and the remaining emissions captured by nature or technology to pull carbon out of the air. (The goal includes emissions other than fossil fuels, like methane from cows on farms, but fossil fuels are the biggest part of the problem.) We’re not on track for that goal. But it still would be technically possible to replace the majority of fossil fuels even more quickly than the middle of the century, if we had the political will.

Doing so would take “an all-out, World War Two-style mobilization,” says Kassie Siegel, director of the Climate Law Institute at the Center for Biological Diversity. “Our country’s met these types of massive challenges before and it can be done. It’s not a matter of you needing new technology; the technology is available today. It’s a matter of speeding the deployment of solutions.”

Mark Jacobson, a Stanford professor who studied what it would take to transition to 100% clean energy in 145 countries—including by using renewable electricity and electrifying buildings, transportation, and industry—argues that from a technical and economic point of view, it would be possible to make most of the changes by the end of the decade. “We have 95% of the technologies we need to transition right now, so if we just deployed as fast as we could, we could transition at least 80% by 2030,” he says.

The changes we need to make include scaling up renewable electricity and battery storage, moving to heat pumps and electric appliances in buildings, switching to electric vehicles, and using electric arc furnaces or green hydrogen at factories. “In terms of what can be done, it’s right there in front of us,” Jacobson says.

Even the hardest-to-decarbonize industries are finding new solutions. This summer, the shipping giant Maersk rolled out a cargo ship that runs on green methanol that can be made from food waste. As recently as 2020, the shipping industry only aimed cut its emissions in half by 2050. When the International Shipping Organization met this year, it agreed to aim for net zero instead. Maersk plans to reach net zero even sooner, by 2045. That’s because so many new innovations in the shipping industry have emerged in the last five years, says Ryan Panchadsaram, an advisor at Kleiner Perkins and coauthor of Speed and Scale: An Action Plan for Solving Our Climate Crisis Now.

The same thing is happening in other industries. In Sweden, a green steel factory is beginning to use hydrogen to make steel instead of fossil fuels; a group of global steel buyers also recently committed to buy 2 million tons of near-zero-emissions steel to help push other steel manufacturers to make the switch. A long list of startups are working on ways to decarbonize cement, another major source of global emissions, in ways that can compete in cost with traditional cement. Startups like Solugen are finding new ways to make chemicals without fossil fuels. Electric and hydrogen-electric airplanes are getting close to commercialization for short flights.

One of the most challenging transitions will be long-distance flight, though hydrogen fuel cell planes or sustainable aviation fuel made from captured CO2 could fill that gap. (And the pandemic demonstrated that it’s possible to replace business trips with video conferencing in the middle of an emergency, like, say, a climate crisis that threatens civilization.) Jacobson argues that from a technical standpoint, it’s theoretically possible to move to 100% clean energy as soon as 2035.

The biggest roadblock to the transition, unsurprisingly, is the fossil fuel companies. “What’s really holding us back is that oil and gas companies are not reinventing themselves as energy companies,” Panchadsaram says. “And as long as that happens, there is a very strong financial motive to prolong the transition.” Fossil fuel companies had an opportunity, after making record profits last year, to invest in clean energy; instead, they gave the money to shareholders and doubled down on oil and gas. Governments also still heavily subsidize fossil fuels, even while they talk about climate action.

The fossil industry is also holding back renewable energy companies from growing as quickly as they could. Renewable companies “have the capacity as an industry to triple renewable energy production in the next seven years,” says Catherine Abreu, founder and director of the nonprofit Destination Zero. “The main thing standing in their way is they don’t have the enabling policy to do it on the ground in country. And a big part of why that is is because of the way the fossil fuel industry has rigged the regulatory and permitting system.”

In Canada’s Alberta province, where the oil and gas industry has a strong presence, the government has currently “paused” approvals on new solar projects. Lawmakers in Texas are considering a similar ban, as “the fossil fuel industry is getting behind politicians and regulators to make sure that they shut down their competitors,” Abreu says. In the U.S., there are enough renewable energy projects in the pipeline to meet 2030 climate goals, but the incredibly slow pace of permitting means those projects aren’t getting built quickly enough. New grid infrastructure also needs to be built, but that’s possible too, as China has already shown by quickly adding high-voltage transmission lines across a sprawling country.

In some developing countries with little infrastructure, the challenge is less about transitioning from fossil fuels and more about building new clean energy systems from scratch. “The thing that enables that is finance,” says Abreu. “The political will of governments to make the transition to reality has to be paired with money on the table to allow for every country around the world to move away from fossil fuel dependence within the same timeframe.”

Right now, the lethargic pace of the transition means that we’re not on track to cut global emissions in half by 2030—and unless things change dramatically, we’ll go past 1.5 degrees Celsius of global warming, a point at which climate impacts get even worse. “We’re six and a half years away at this point, and every day that’s squandered, the challenge of attaining that goal is harder and harder,” says Max Holmes, president of the Woodwell Climate Research Center.

But it’s still possible to move faster from this point on. And if we do pass the 1.5-degree threshold, we’ll need to work even harder to cut emissions to avoid higher temperatures, and ultimately to bring the global temperature down. “With every increment of warming, the impacts of climate change get worse, more people are impacted, more ecosystems are impacted,” Holmes says. Speed is critical.

A fast transition is feasible, says Panchadsaram. “If we all set our minds to it, could we do it? The answer is absolutely yes,” he says. “This isn’t science fiction anymore.”