Presumably what should matter (assuming preference utilitarianism) when we evaluate an act are the preferences that exist at (or just before) the time of commission of the act. If that's right, then the non-existence of those preferences after the act is performed is irrelevant.
The Spanish Inquisition isn't exculpated because it's victims' preferences no longer exist. They existed at the time they were being tortured, and that's what should matter.
So it's fine to do as much environmental damage as we like, as long as we're confident the effects won't be felt until after everyone currently alive is dead?
Haven't had one of these for awhile. This thread is for questions or comments that you've felt silly about not knowing/understanding. Let's try to exchange info that seems obvious, knowing that due to the illusion of transparency it really isn't so obvious!