[msandford]

Right but that's incredibly naive and uncreative. It presumes that fossil fuels are the ONLY way to do certain things, unless you can spend millions of dollars proving otherwise.

For example, right now most steel is made in electric furnaces which can be powered by coal, nuclear, gas, oil, solar, hydro, etc. What's the right tax for imported steel then?

Let me now make a list of a bunch of other things that are in a similar category: aluminum, most other metals, rubber, plastics, glass, etc.

Machines that are used to process raw materials may themselves be made of raw materials which are sourced in various ways. And those machines may be powered by dirty fossil fuels or clean renewables. Which means that components -- as opposed to raw materials -- are also going to be very difficult to properly classify and tax.

The same for subsystems and full assemblies and entire products.

It's a lot more complicated than "do some math and then apply a tax"