In reality, there is no such thing as “clean” coal in America today. Coal cannot be called ‘clean’ until its CO2 emissions are captured and stored safely.
So, using this same definition for all things, I am guessing that there is no such thing as ‘clean’ trees? Or ‘clean’, say, people, or squirrels and such?
Today, coal power plants emit carbon dioxide (CO2), the pollutant causing the climate crisis. A third of the America’s carbon pollution now comes from about 600 coal-fired power plants.