If we can dig and mine up coal, does that mean that it was once a tree that burned down?

Question

If we can dig and mine up coal, does that mean that it was once a tree that burned down?

In: 245

Answer 1

What missing from the discussion is the carbon in coal has not been in the atmosphere for millions of years. And it has accumulated toxic elements that are released as well (sulfur & mercury).
The heavy mercury content of large game fish in the oceans is from burning coal.