As an interesting aside to carbon taxes and such (which appear to be working to a degree):

Was shopping for ETFs a while back and came across the WealthSimple SRI portfolio which is based on their funds. They use a normal ESG index but it also de-lists any companies in the top 25% of emissions for their category.

This would seem to help avoid some collusion and complacency in industries like software that are just at a natural advantage in absolute terms compared with, say, coal plants.

Of course, it's a retail investor and consumer driven thing which leaves too much on the table for some, but I think there's something to the idea of getting companies to compete on the rate of improvement relative to each industry, in addition to internalizing some of the costs through taxes.