Dollar costs of physical things (pre tax) quite accurately measure how much effort it takes to produce/acquire that thing. Hydrogen being more expensive than X quite stronly suggests that it is much more effort to get than X.

I agree, that’s why I say tax the right things and subsidize the right things.

All well and good until you have producers burning (or otherwise using) the cheap, taxed fuel to produce the expensive, subsidized one while creating more net pollution in the process. It's hard to get this stuff right at the best of times.

Carbon credits should also fix that. The bigger problem is getting everyone to agree something needs to be done.