As I understand, I may be wrong, burning it releases the carbon to the atmosphere, but also releases some noxious chemicals unless burned at high temperatures, which often requires energy input. And any ash that's left can be problematic too.

Also I believe landfills will be future mines.

I wonder if it's possible though to turn garbage to charcoal, to sequester the carbon in a more stable form, and at the same time burn the 'wood-gas' for energy. Like bio-char, garbage-char.