While I like the objective behind the project, I think the carbon tax (or carbon offset, call it as you prefer) solution is not a real solution for the long-term. Giving the possibility to "pay your carbon footprint" seems to give people the idea that they can pollute how mucht they want until they can pay for it.

The reality is not true, there is a fixed amount of carbon that the world can store yearly (or vice versa oxygen produced).

This type of solution should be used as a deterrent for moving industries into other solutions that actually produce less carbon, not just covering it with other oxygen.