A pollution tax is really the only viable solution though. Playing whack a mole against individual entities and activities will never solve the problem, and creates a lot of legislation.

So long as pollution and carbon are free or cheap, people will find wasteful ways to generate it.

Incentives work, and taxing carbon and pollution will incentive green alternatives.

In the specific case of proof-of-work cryptocurrency, I don’t think a carbon tax is directly useful: If it’s unilateral then mining trivially shifts across borders; if it’s global then it’s an inflationary pressure on the coin price which offsets the reduction in mining you might otherwise expect.

a pollution tax will not work. That just becomes the price of doing business and that cost is factored into other areas of the business model. Even worse, it just gives more capital to inefficient governments

> That just becomes the price of doing business and that cost is factored into other areas of the business model.

Yah that's the point and business with less environmental impact will be more competitive. Industries/products with more of an impact will be more expensive, reflecting their true cost.

> Even worse, it just gives more capital to inefficient governments

Most pollution/carbon taxes are proposed to be revenue neutral, i.e. all the proceeds are returned to the tax base. This is also important because like other (non-luxury) consumption taxes, a carbon tax is regressive.

It becomes the cost of doing dirty business.

Solar is taking off not because we banned coal, but because it's cheaper than coal. If coal and natural gas were taxed according to their carbon output, solar would be even more ahead, nuclear may become more attractive as well.

Aluminum is heavily recycled not because it's green, but because it's significantly cheaper than mining new.

Incentives work. The free market responds to incentives, and works around regulations.

I have a few disagreements with the MMT crowd, but on this one point they are transparently correct: the exact level of taxation has little relationship to government ability to spend. Talk of "giving more capital" to governments shows a deep misunderstanding about the nature of fiscal constraints.

> other areas of the business model

And what are those? District heating?