I feel like an ethics-optional group that wants to really end the use of coal could run a campaign of breaking into or drilling down to the most profitable commercial coal seams and lighting them on fire. More Centralia, Pennsylvanias, especially in populated areas, would probably permanently dampen the domestic industry and drive prices far upwards leading to the faster growth of alternatives. The obvious tradeoff is, those seams your group lit are going to burn for a very very long time, so you’re causing some emissions in exchange for a global reduction.