Renewables can replace fossil fuels as an energy source. To undo a century plus of burning fossil fuels, you'll need a revolutionary energy source that outputs

Renewables can replace fossil fuels as an energy source. To undo a century plus of burning fossil fuels, you'll need a revolutionary energy source that outputs an order of magnitude more power. Maybe fusion, or maybe something that we cannot yet fathom. You can imagine this all coming to a happy ending, but at this point it's all up in the air. Both the CO2 and whether it'll ever come down again.