ecological rewards

In addition to percentages, points, cash back etc, does anybody have experience with 'ecological rewards' programs tied to a credit card? In the Netherlands, one of our banks here recently launched what could be called a 'climate credit card'. When using this card to pay for my expenses, the bank calculates the climate consequences of my consumption. This is expressed as the number of kilograms CO2 that have been emitted to deliver the product of service of my purchase to me. The bank then commits to invest in projects that aim to reduce the same amount of emission elsewhere, preferably in developing countries. Costs me nothing, and appears to be a voluntary scheme. Any views on this?

[Jeremy]

Very interesting. But no, I've never heard of such a card in the US. I don't understand how they could know what the impact of your purchases are. If you spend $100 at the grocery store, all they know is the amount and location of purchase, not the actual items, so I don't see how they could calculate that.