Recently my wife suggested that we offset all our emissions. Even though I found this a noble idea, I was worried that we might lose a fortune by doing so. This worry is unfounded (at least for a Swiss): Offsetting my yearly emissions costs around $300, possibly even less.
Here is an observation about this number: If everybody were to live a carbon-neutral life, then offsetting emissions would be much more expensive. In that case, it would cost me (to make an arbitrary guess) $10’000 rather than $300 to “compensate my life”. If everybody else were to offset their emissions, I couldn’t just pick the low-hanging fruit of cheap mitigation measures but would have to make use of very costly emission reduction measures. So, which number is the right one? Can I claim to actually have offset my emissions if I only pay $300? In some sense, the answer is “yes”. There is nothing incorrect about the following assertion: The atmospheric concentration of CO2 is the same if I emit and pay $300 to an offsetting company as it were if I weren’t around on this planet at all. Thus, my payment of $300 actually does offset my emissions. (Admittedly, many people don’t believe that offsetting works in practice; let’s set these worries and the uncertainties aside for the moment).
However, many are interested in compensating their emissions for a certain specific reason: they want to do their fair share in humanity’s common task of protecting the climate. If that is the reason for their interest in compensation, then things look different. If you are keen on doing your fair share and if you believe that the fair share consists in bearing your part of the overall costs that would arise if everybody were to do the right thing (and if you believe the right thing presently consists in living a carbon-neutral life), then your fair share would consist in paying $10’000 rather than $300. Another way to see this goes as follows: In order to do your fair share, you have to pay two bills. First, you pay $300 to actually offset your own current emissions. Second, you pay $9’700 on account of making mitigation measures more expensive for others in the future. Mitigation measures are more expensive for them because you have already exhausted the low-hanging fruit – your mitigation imposes an externality on them, so to speak.
An objection to this line of reasoning might arise: It is unrealistic that everybody else will offset their emissions. So, yes, if you want “to do your part” you have to pay the first bill of $300. But the second bill must be calculated differently: You have to estimate how much more expensive future mitigation will be on a realistic assumption about how much more future mitigation there will be (rather than on the assumption that everybody will fully do their fair share of mitigation in the future). In that case, the true price I would want to pay for compensating my yearly emissions would be something in between $300 and $10’000.
These thoughts are all rough. The basic message is this. Going carbon-neutral might seem extremely cheap. However, in order to know whether the moral goal you want to achieve by going carbon-neutral is really as cheap as it seems, you need to go into difficult philosophical territory. You cannot know how much it costs you without carefully examining the moral reason you have for going carbon-neutral in circumstances where others don’t go carbon-neutral. The literature on duties under partial compliance is the place to look for answers (and, when it comes to calculating actual numbers, the economic literature on the shape of Marginal Abatement Costs curves is relevant as well).