It's free in the same way that stealing is a way to get things for free. When you pay for petrol for example, the money you pay goes to the oil extractors, refiners, distributors, etc. for the transfer of oil from the ground to your car. But you're not paying the earth for the taking of those resources (carbon budget I can be considered a "resource"). It's analogous to paying for someone to steal for you.
In an efficient market, the price you pay would include a carbon tax paid to the "Earth fund", and the fund would be used to replenish the planet's resources (eg. by carbon capture and storage).
But until then, the version of capitalism we operate is one where the largest participant (planet Earth) is only being stolen from; never being paid.
That's pretty much what carbon credits are. We have them, they just need to be expanded and developed. And ideally not subverted and transformed into just another tax.
The current system, as far as I understand it, is a market. One of the better ideas I've seen governments implement. You can purchase carbon credits only to the extent other carbon credits are on the market - like people planting trees.
So do you think all the people breathing air right now are stealing it unless they first ask Mother Earth whether they may have it? What should the payment be?
Sorry, but it's not at all common sense to me. Where is the line? Am I allowed to cut down a tree on the property I own? Or is that stealing? I brought up the extreme case of breathing because it is literally putting carbon directly in the air.
How about this: The CO2 that you're breathing out right now has been bound during your lifetime, and can certainly be expected to become bound once more during your lifetime. The same cannot be said for CO2 emitted from the burning of fossil fuels.
In an efficient market, the price you pay would include a carbon tax paid to the "Earth fund", and the fund would be used to replenish the planet's resources (eg. by carbon capture and storage).
But until then, the version of capitalism we operate is one where the largest participant (planet Earth) is only being stolen from; never being paid.