So wood shortages reappeared, magnified by rising populations and even greater demands for metal. That led them to the much cleaner hard coals we use today. These deep coals also served to replace wood in the smelting process. With their whetted appetite for fuel and metal, our 17th-century forbears became desperate to keep that appetite fed. But by now our story sounds all too familiar.
Human ingenuity creates new human appetites which are eventually met by new ingenuity.
It's as frightening as it is heartening to see how we can always find 11th-hour ways to keep those appetites fed. Penguin Books, 1976.