What happens when coal is gone?

Well?

But a combination of sources, perhaps including saltwater-grown plants, could get us there in the relatively near term. “Oil will disappear and there’ll be no change at the gas pump because there’ll already be technologies in place,” predicts Laughlin. “The good news is once you build these [Fischer-Tropsch] plants, you can use anything, including garbage, for the biofuel conversion. The big problem is the initial capital cost.” We can adapt the facilities over time.