What up call for whom? The USA is a net fossil fuel exporter. China is still heavily dependent on fossil fuel imports (as well as fertilizer produced from natural gas) and those imports would be interdicted in any major conflict. Of course the Chinese leadership is well aware of that vulnerability and taking steps to mitigate it.
The U.S. exports fossil, yes, but we import a huge amount as well because many of our refineries aren’t setup to process light sweet crude and it’s also often cheaper to buy oil, refine, and use it on the coast than it is to move it across the country from somewhere in the Dakotas.
If we had a war with China, it’d go much worse given their much greater resources and knowledge of how to hit those import routes for maximum impact.