This is the first article that I have read that seems to give some options/guidance in how to report on carbon emission.

Our company is a small to medium sized estate agents and other than office equipment being used our main carbon emitting asset would be our fleet of cars. we have been changing these to electric as the leases come to an end and use golf carts on private roads but this article has given me food for though on how to incorporate emissions into internal reports.

There would appear to be two barriers for us to impliment one of these options and that would be to find a cost per tonne of carbon and also to measure the carbon tonnes. an arbitrary number could be used for costs much as the war Acciona did as it kept increasing the charges but I would need to investigate ways to measure the usage.