Three kinds of offsetting

Distinguish the following kinds of "offsetting" behaviour:

Preventative offsetting -- when potential harms depend on just the global amount of something (say, greenhouse gas emissions), it seems that one can prevent the potential harm done by one's contributions by "offsetting" or paying to reduce others' contributions, so that the net effect of one's behaviour leaves the global magnitudes unchanged.

Cause-specific (or harm-type) offsetting -- when you cause a harm of a certain type, but then seek to 'offset' the badness of this by preventing a like harm from occurring elsewhere.  E.g. donating to a relevant environmental charity after polluting your local river.

Cause-neutral (or net utility) offsetting -- when you cause a harm of a certain magnitude, and then seek to 'offset' the badness of this by preventing a similar amount of harm elsewhere.  E.g. donating to a global poverty charity after polluting your local river.



Preventative offsetting seems the most easily justified.  While he doesn't use this exact terminology, this is the basic idea that Will MacAskill appeals to in Doing Good Better to distinguish carbon offsetting (which he thinks can justify our carbon emissions) from things like murder offsetting (which surely can't justify murder).

But preventative offsetting can only get us so far.  For one thing, it's not entirely obvious that even carbon offsets are entirely preventative: it seems an empirical possibility that there could be some localized effects to greenhouse gas emissions, such that planting trees in Peru doesn't literally undo the effects of flying around Europe.  Moreover, our modern lives entail all sorts of localized environmental harms (e.g. air pollution from driving cars, creating demand for electricity that's partly from non-renewable sources, habitat destruction to make room for our housing and food needs, adding to oceanic plastic buildup, etc. etc.) that aren't subject to preventative offsetting.  So if we want to be able to "make up for" these harms we (and our children) cause, we will need to appeal to some form of non-preventative offsetting (whether cause-specific or cause-neutral).

Perhaps the most promising way to do this (without absurdly justifying murder offsets or the like) would be to develop Scott Alexander's idea that "you can offset axiology, but not morality."  Scott happened to appeal to a specifically rule-utilitarian conception of morality, but we can broaden the idea beyond this.  The basic idea (as I would prefer to develop it) is just that you can offset diffuse harms but not specific wrongs or rights-violations.

On any plausible conception of rights (whether foundationally consequentialist, contractualist, or taking the rights themselves as foundational) we have a right that our neighbours not murder us, but no right that they refrain from exhaling carbon dioxide into the atmosphere.  So there we have our easy cases: carbon offsetting is legitimate, whereas murder offsetting is not.  This analysis also plausibly identifies the difficult cases: reasonable theories disagree about whether factory farming involves rights violations or just harms to the animals' welfare, and so the legitimacy of meat offsetting (e.g. paying others to become vegetarian in your place) is a similarly open question.

My hope is that this analysis could convince even non-consequentialists that we can legitimately offset the environmental harms entailed by procreation (and indeed by our own continued existence), thereby undermining the environmental anti-natalist arguments of Travis Rieder, Sarah Conly, and others.  Our everyday environmental externalities seem like precisely the kind of diffuse, untargeted harms that can legitimately be offset, after all.

I'm further inclined to think that there's no clear moral reason to prefer cause-specific moral offsetting: if we can more efficiently make the world a better place through other means, we should feel free to do so.  And this makes it much more feasible in practice to successfully offset the harms we cause: rather than having to somehow find specific charities that address each specific kind of harm we cause, it suffices to simply do more good than harm overall in our lives (which I expect is already achieved by most law-abiding folks just through their everyday social and economic contributions to society, before even taking into account any explicit philanthropy).

Any thoughts / objections?