Microsoft announced its commitment to become 100% carbon neutral for all of its operations worldwide (data centers, software development labs, offices, and employee air travel) in the upcoming fiscal year. Fantastic!
A couple of interesting aspects of this are:
First of all, they are using CarbonSystems, not any of the known other players like HARA or SAP. This provides them with better real time view into their footprint and can drive immediate actions by the various business units.
Secondly, they implement a carbon fee chargeback model for all emissions which gets pooled in a central fund from which they buy Renewable Energy Credits. A good idea - they included the CFO as a prinary stakeholder. In this approach, every business units knows about its impact and is incentivised to take action to reduce exposure to the CFO.
For more details, here is their recently released white paper.