The problem with any of these measures is leakiness, particularly in light of global fuels trade, emissions, and global warming impacts. I somewhat agree that

The problem with any of these measures is leakiness, particularly in light of global fuels trade, emissions, and global warming impacts. I somewhat agree that taxing fossil fuels directly is the most direct route, though that faces a number of challenges: - There's no one single global tax authority. Several of the largest fossil fuel extractors (China, India, Indonesia, for coal, Saudi Arabia, Russia, and China, for oil, and Russia, Iran, Qatar, and China for natural gas) would tend to be noncompliant with such impositions.[1] - Outsourced manufacturing means that a secondary tax on imports of goods or services by carbon emissions would likely be necessary. I'm not sure how this would comport with existing trade treaties. - Taxes would hit low-income countries much harder than rich ones. This is one of the common sticking points for virtually all emissions- and limits-based interventions, and has been since the 1970s if not earlier.[2] - Any such taxes would have to be adjusted based on actual atmospheric greenhouse gas concentrations. Not merely CO2 but other emissions as well. Effectively the goal is to set a net emissions and warming budget and adjust a tax scheme to achieve that. - Black markets would undoubtedly emerge, though the scale of such markets would make detection relatively straightforward. The more likely complication is that major actors (the US, China, Russia, India) are nuclear states, and direct interventions would entail their own risks. - As wealth is power[3], the passing, adoption, and enforcement of such a tax would likely be highly challenging. I don't have much by way of alternative suggestions, but I do somewhat agree that a direct economic mechanism aimed at the source would be preferable. ________________________________ Notes: 1. Five largest extractors each are, coal: China, India, USA, Indonesia, Australia; oil: USA, Saudi Arabia, Russia, Canada, China; natural gas: USA, Russia, Iran, Qatar, China, sourced from BP Statistical Review of World Energy 2022. 2. Excellent contemporaneous discussion of this in William Ophuls, Ecology and the Politics of Scarcity, 1977, particularly Chapter 7. <https://www.worldcat.org/title/2524932 https://www.worldcat.org/title/2524932> <https://archive.org/details/ecologypoliticso0000ophu https://archive.org/details/ecologypoliticso0000ophu> 3. See: Hobbes and Adam Smith.