Coal has been an important part of the energy mix for hundreds of years. It has an incredibly high level of energy for its weight. It has been easy to find and extract, and literally powered much of human development.
Nowadays, it gets a bad rap because of the airborne pollutants that it creates when being burnt. These pollutants directly cause misery (and death) for millions of the worlds population.
In some cases, the burning of coal completely blocks out the sun, and the blue in the sky, creating a post apocalyptic feel for everyone.
We can respect the help that coal has given us, and understand that technology has been developed to capture these pollutants. If we ever perfected ‘clean coal’ so that there were no airborne particles released, coal might tick a few more ‘green’ boxes.