It's pretty hard to hide the fossil fuel-burning power plant generating your PoW. If your local government or citizens won't stop you from polluting the enviro

It's pretty hard to hide the fossil fuel-burning power plant generating your PoW. If your local government or citizens won't stop you from polluting the environment, other governments can impose retaliatory tariffs or even sanctions on your government, and citizens of other countries can boycott your country's goods and services. Make the financial penalties for tolerating fossil fuel-burning PoW steep enough, and your power plant gets shut down.