NEW YORK – Washington’s trade war with Beijing doesn’t pose much of a direct threat to US coal miners, since just a tiny percent of their sales go to China. But Appalachia may feel some heat from the sinking value of the Chinese yuan.

A weaker Chinese currency makes it more expensive for the Asian giant to buy coal from the US or elsewhere. That’s particularly important for metallurgical coal – a component in steelmaking with a global market so tight that prices surge or dive when supply or demand fluctuates by a handful of tons. And since met coal is generally priced in US dollars, a falling yuan could prompt China to depend more on its own vast reserves rather than imports.

“There is concern developing in the met coal market as to how China’s weakened currency might impact its buying appetite for imported coals,” Mark Levin, an analyst at Seaport Global Securities, said in a note Tuesday. “When the Chinese hiccup, the rest of the global market tends to convulse.”

For now, fears appear to be speculative.

US coal exports climbed to the highest level in five years in April, in part due to strong demand from Asia, the US Energy Information Administration said Tuesday. Meanwhile, Chinese metallurgical coal production was down 2% through May compared with the prior year, and it’s still cheaper for the country to import the commodity than mine more of its own, according to Andrew Cosgrove of Bloomberg Intelligence. That’s helped keep global spot prices for metallurgical coal around $200 a metric ton, almost three times as high as when the market bottomed out in late 2015.

But China’s influence is vast. Two years ago, it curbed its own production of metallurgical coal, and global prices quadrupled in value, to almost $310 a metric ton. Prices have stayed above $140 since, benefiting US miners in places like southern West Virginia and Alabama, where companies went from bankruptcy to profitability and production has continued to rise.

“If the Chinese currency continues to weaken, it has the potential to cause Chinese imports to fall significantly,” Levin wrote. “How much the weakened yuan affects the coking coal market from here depends on the sustainability and severity of the decline.”