We're huge supporters of a carbon tax, but there are significant challenges, both technical and political. If we had perfect information and the political will, I think the approach you describe would be great—in the meantime, unfortunately, the market needs tools like Bend.

I actually wrote a blog post on the subject, if you're curious: https://bend.green/blog/the-path-to-a-carbon-tax

"It’s a relatively simple idea: corporate CO2e emissions are tracked and companies are charged some flat rate of dollars per kilogram."

As I mentioned, tracking and measuring emissions is hopelessly complicated. It's far easier to tax the carbon content of the fuel where the fuel is produced.

As for taxing, we already tax gasoline (rather heavily). I don't really understand why taxing the carbon content is resisted so strongly. Taxing the carbon content would also do things like make natural gas more attractive than coal, because ng has twice the energy in it per carbon atom.

As for the amount of the tax, one starts out with a small carbon tax, then gradually increase it until the CO2 emissions go down. This also gives the market time to adapt.

It is impossible to determine the carbon footprint of a mere pencil, let alone some large business operation:

https://news.ycombinator.com/item?id=32175325

One is grass roots and the other top down.