NicoMost taxes are scaled proportionally to the revenue or profit of an activity. A common tax scheme is for a company to pay a percentage of their profits, usually increasing as profit increases.
A carbon tax is proportional to the greenhouse gas emissions of an activity. Some amount of money must be paid for every ton of CO2 emitted by a company. The precise details very across suggestions, but all carbon taxes are an attempt to specifically disincentivize activities with out outsized climate impact.
A good summary of what countries have implemented carbon taxes can be found in this Our World in Data link: https://ourworldindata.org/grapher/carbon-tax-instruments