Are Historical Emissions Harmful? Postscript

And then, there is of course a fourth reason why it is debatable whether historical emissions count as harmful: The Non-Identity-Problem.

The Problem in a nutshell is this: If in 1970 a people decided to pursue a policy of rapid economic growth which at the same time has a big impact on climate, this decision not only worsens the condition of persons living in 2070 but it also influences the whole course of history, including which persons exist at all in 2070. A given person in 2070 who would not exist but for the policy chosen in 1970 cannot claim to be worse off had a greener policy been pursued in 1970 because with such a policy the person would not be better off but rather not exist at all.

Quite a mindboggling problem.

A lot of the solution turns on, roughly, whether one can understand "harm" in other ways than "making worse off". For a discussion, see Lukas Meyer's entry in the Stanford Encyclopedia of Philosophy on intergenerational justice.