> but I don't see such tax happening any time soon

Curious, why do you feel this way? From where I sit, carbon pricing has been slowly (but surely) making its way into policy all around the world: https://www.nytimes.com/interactive/2019/04/02/climate/prici...

"Canada currently has one of the most ambitious carbon pricing programs in the world. Under Prime Minister Justin Trudeau, the Liberal government has enacted a nationwide tax on oil, coal and gas that starts at $15 per ton of carbon dioxide this year and will rise to $38 per ton by 2022. Most of the revenue will be refunded to Canadians on their tax bills; the government estimates that these refunds will offset higher energy costs for about 70 percent of people."

"With Congress largely gridlocked on climate policy, the main carbon pricing efforts in the United States have unfolded at the state level.

In the Northeast, nine states currently participate in the Regional Greenhouse Gas Initiative, a cap-and-trade system that auctions to power plants a steadily dwindling supply of carbon pollution permits. Carbon prices under this system have been fairly modest to date, and it is unclear how much the prices themselves have driven emissions reductions in the region. But states have used the money raised by the auctions to invest in efficiency and clean energy programs.

California, meanwhile, has enacted its own cap-and-trade program that goes beyond power plants and also covers manufacturers, refineries, and other polluters. Here, too, carbon prices under the system have remained modest to date, in part because the initial cap was set fairly high, and most of California’s emissions cuts to date have come as a result of other climate policies. Those include the state’s efficiency standards for buildings, and aggressive renewable power targets. State officials are now struggling to tighten the cap so that it drives bigger cuts in future years.

There are some signs that carbon pricing could expand further in the states. Virginia and New Jersey are making moves to join the Regional Greenhouse Gas Initiative, and several Northeastern states are planning a similar program for cars and trucks that would put a price on transportation fuels and invest in mass transit, electric buses or other low-carbon solutions."

"Since 2011, China has been experimenting with cap-and-trade programs in several pilot cities, including Shanghai and Shenzhen. The country plans to gradually roll out a nationwide cap-and-trade program starting in 2020, with several years of testing before expanding to major sectors like electricity, steel and concrete.

If China manages to follow through, it will have created the largest carbon-pricing program in the world. But the government has not yet finalized key details, like how high it will set the overall emissions cap. Chinese officials have been talking with representatives from California and the European Union, trying to learn from their often-rocky experiences in designing cap-and-trade programs."

It hasn't been without its hiccups and we haven't reached maturity yet, but it's clear which way the political winds are blowing. The same can be said for crypto, funnily enough.