Yesterday, I examined the cost of I-1631, the carbon tax, for the first full year in 2021. It is useful, however, to look at how that cost increases every year. Here is a quick guide to how the carbon tax increases gas prices through 2040.

The initiative increases the tax by $2 per metric ton plus inflation each year. This assumes the 15-member board doesn’t declare Washington to be on the path to meeting the CO2 reduction goals.

For simplicity’s sake, I’ve assumed a three percent inflation rate. As you can see, the tax almost doubles by 2025. A two percent inflation rate reduces that only slightly, with the tax going from 25 cents per gallon down to 24 cents per gallon in 2025.