April 1, 2026 - Coal has long been the world’s top source of fuel for electricity generation. But many countries had been phasing out their use of coal in recent years, in part because of all the planet-warming emissions it generates.

Demand is rising once again, though, particularly in Asia. In the month since the war in Iran began, the global price of coal has jumped more than 20%.

To talk about coal, we first have to talk about a different fuel: natural gas.

Kenneth Gillingham, a professor of environmental economics at Yale University, said about a fifth of the world’s liquified natural gas typically travels on tankers through the Strait of Hormuz.

“The consumers of that, the people who buy it, tend to be in Asia,” he said, countries like China and India.

They’ve been ramping up their use of natural gas in recent years. But these days coal is more readily available. And they still have plenty of coal-fired electricity plants hanging around, said Amin Mohseni-Cheraghlou, an energy economist at American University.

“Given the current conditions they can relatively easily go back to coal,” he said. “There is a lot of capacity.”

That capacity is getting fired up once again, to lessen the blow of rising gas prices.

“It's just natural for those economies, try to switch back to coal as much as possible,” Mohseni-Cheraghlou said.

Thailand and Taiwan may unretire coal plants that had been shuttered, while South Korea and Japan have suspended climate laws that cap coal burning at some power plants, said Kenneth Gillingham at Yale.

“Maybe they'd run some of the time, they'd run occasionally. Now they're being run all the time,” he said, adding that the shift will be felt by the climate. “I think this is a big enough impact that we will see a little jump in emissions.”

But this energy shock could have the opposite effect in the longer term. Daniel Cohan, a professor of environmental engineering at Rice University, said it could incentivize countries to invest more in renewables.

“With a few years time, that's when you can start building out more wind, solar, and batteries, because those are the cheapest forms of electricity available,” he said.

Plus, they’ll make those countries less reliant on imported fuels.