Fun fact: coal is produces more pollution of all types ranging from radioactivity to CO2 to metals to acid rain generators (SOx/NOx) to ozone (NOx again) to black carbon aerosols (or even black carbon on snow!). Coal extraction is bad for workers and the environment, and it's often dangerous to mine. It is the worst energy technology period.

We're playing stage 3 of Power Grid, and coal is already getting more expensive. Let's just stop burning it now please.

Also we should leave some coal around just in case we destroy society and our descendants need to bootstrap a civilization again. It's hard to do that without an easily accessible fossil fuel.