On a personal level, it would be pretty easy to deal with such a tax: I can think of only 2 use-case for normal people to buy fossil fuels directly: to power IC

On a personal level, it would be pretty easy to deal with such a tax: I can think of only 2 use-case for normal people to buy fossil fuels directly: to power ICE and to heat their home. Programs to help people migrate away from using ICE and oil boiler already exist in many places. By starting small and giving a timetable, you signal people that they have x years to act and that they really should migrate away from using those. A carbon tax on raw ressources would be most impactful where the real emission are happening: transportation, industry and electricity generation. For sure, pricing the externalities of the use of fossil fuel at the source would make some things that are currently cheap, expensive: air travel, cement production... But if those activities are destroying the environment, maybe it's not such a bad idea to make them more expensive. Then you would see real effort to find solution to lower the carbon footprint of those. When I'm talking about a gradual increase, I'm thinking about a slow gradual increase over a long period (eg: 20 years+) so the carbon taxation program starts pretty painless for most and leave enough time for the world to adapt and get rid of that carbon dependency.