I go back and forth on the push for carbon neutrality for large companies (as opposed to some form of carbon tax). I'll give a few examples that I've seen first-hand in my work as a consultant.

1. A large state-owned African agricultural company is using satellite and soil-sample data to measure the carbon sequestration potential of agricultural land if certain farming techniques are used (no-till, etc). They use satellite and soil-sample data feeding into a biological model implemented in fortran (from some academic paper that may or may not be replicated) for the estimation. The plan is to go to farmers and ask them to switch the technique. The company would sell carbon credits, give the participating farmers a cut and keep the rest. This has great potential! but the large-scale implementation is very difficult manage. The company would at least need to randomly check in on participating farmers. It should also take soil samples over time to make sure the technique is working. Carbon credit sellers should be auditable, but the government relations and size of the company might make that difficult to do rigorously.

2. An analytics tool hopes to help large companies identify the parts of their supply chain that can reduce the overall carbon emissions of a product with the lowest price increase to the end-consumer. Think about BMW sourcing steel from China for example. If this helps companies actively manage their supply chain in order to lower emissions, then suppliers will adopt to low-carbon techniques over time. The problem is that it requires suppliers to disclose their emissions accurately. Many supply chains in carbon-intensive industries are global and fragmented. If a bad-actor supplier on the other side of the world lied and got caught, they could just change their name and carry on.

3. Global supply chains also present issues with carbon taxes at the drilling/mining site. You can't force foreign countries to tax this (and if you did they would be incentivized to cheat), and you can't force foreign companies to accurately disclose energy use. A domestic energy tax would make local manufacturing uncompetitive, which is something most countries are not willing to sacrifice.

The debate between carbon neutrality vs carbon/extraction taxes is the choice between inventing an entire new bureaucracy of enforcement (carbon audits, carbon disclosure, etc) or the impossible task of rallying and enforcing global action (every country imposes the same tax, no exceptions). As an engineer, I understand the seeming beauty and efficiency of the second option, but I think the first is ultimately going to be our best bet.