Reply #25: "The world will adopt alternative energy sources when coal is outlawed."

[Statistical]

Except nobody has the authority to "outlaw" coal.

The US can ban coal but personally I think that is the wrong aproach. A high and increasing carbon tax would be more flexible.
Steel for example requires coal so likely there would be exceptions to any ban and once you make exceptions then politicis gets involved and more exceptions get in and the "ban" ends up very weak. Simply put at $50 per ton carbon tax "new coal" (i.e new plants needs to be built) becomes more expensive than natural gas, nuclear, or wind. At $120 per ton carbon tax even coal coal becomes more expensive than the alternatives. So just tax carbon. No need to ban anything.

As far as other countries they will need to reach their own decisions. We can try and educate but the best thing we can do is adopt alternative energy to bring the cost down. Third world won't burn coal because they like it they will burn it because it is cheap and if you close the "cheapness" gap the more alternatives will be adopted.