[LorenPechtel]

Coal has already poisoned the entire world for centuries to come.

Consider the advice about not eating too much in the way of predator fish. That's because of contamination, mostly from coal plants.

Chernobyl is as bad as a nuke plant accident can be. Whether the core actually went prompt critical or destroyed itself just before doing so we will probably never know, but that's the worst that can happen. You simply can't shift the multiplication factor fast enough to make a bigger boom. Chernobyl is a drop in the bucket compared to what coal has been doing for ages. You can't get a China Syndrome accident, a molten mass digging it's way down will change shape as it goes--either going subcritical and quickly running out of heat, or going prompt critical and destroying itself.