That works as long as: 1. Startup costs for a coal company are high (I assume they are, but it depends on the region) 2. The company has exclusive right to th

That works as long as: 1. Startup costs for a coal company are high (I assume they are, but it depends on the region) 2. The company has exclusive right to their coal, and it's hard to find other sources of coal that aren't claimed by other companies (not sure on this one, but it also depends on the region) (these first 2 conditions are in place to make sure that no one starts another coal company after the buyout) 3. The marginal cost of buying a coal company for that purpose is lower than the marginal cost of starting a company which has the same net amount of positive climate change externalities.