A carbon tax essentially charges a fee on greenhouse gas emissions, aiming to account for their environmental impact—an externality not usually priced into the cost of fossil fuels.
The concept of a carbon tax has been considered for well over a decade.[0] While it might be a suitcase term on its own – different people interpret the phrase differently – the overall concept has been studied, has a lot support and popularity from economists.[1][0]
Several strategies exist to implement a carbon tax, but a widely favored method is a market-based, "revenue-neutral" approach. Here, the funds raised from the tax are redistributed (through various means, not necessarily something like UBI) to offset any financial burden on consumers or businesses.[2]
As far as my understanding goes, a carbon tax is simpler to put into practice—and explain—compared to other alternatives like specific environmental regulations or cap-and-trade carbon pricing schemes.[3]
[0] https://www.kentclarkcenter.org/surveys/carbon-taxes-ii/ [1] https://www.econstatement.org/ [2] https://www.americanactionforum.org/research/comparing-effec... [3] https://www.mdpi.com/2071-1050/12/20/8680/pdf