Talk about action on climate change almost always comes around to the matter of saving future generations from ecological disaster. Certainly, an argument might be mustered for the view that action is required because future generations ought to matter to us. It’s here, in talk of sustainability and future people, that a difficult objection sometimes surfaces in philosophical quarters. 

The thought is owed to Derek Parfit, and it’s called the identity problem. Here’s the gist of it.

Personal identity is a hit and miss affair. If an alarm hadn’t gone off when it did, if someone missed a bus, if the lighting and the music weren’t quite right, the particular sperm and ovum required to make you wouldn’t have met, and you just never would have been. The ecological policies we adopt will have all sorts of consequences, not just for alarms and buses, but on who ends up existing. 

Suppose we pursue business as usual, and continue pumping greenhouse gasses into the atmosphere willy-nilly. We wreck the planet and leave to those who come after us a very unpleasant world. Given the contingency of personal identity, the people alive in that unpleasant future wouldn’t have existed had we adopted greener policies. So they’ve got no grounds for complaint about the world we leave to them.  Therefore, the lives of future generations need not figure into our reflection on the environment.

That can’t be right, can it? Reflection about action on climate change depends a lot on right and wrong, responsibility, justice, in short, on doing the right thing. When we think about the morally right course of action, say how we treat a friend, what we don’t think about is whether or not that person has grounds to object to our course of action. We think about their pleasures and pains, their preferences, their hopes and needs, maybe guiding moral principles or maxims and so on. The identity problem seems to miss this fact about reflection on ethical action generally and on the moral dimension of action on climate change in particular. We want to do what’s right, and that’s something other or more than ensuring that others have no grounds for objection.

You can also, if you like, go utilitarian and think of the happiness of future people. You’ve got a choice between two sets of people: unhappy ones in an unsustainable world or happier ones in a better world. If you think happiness matters, you should choose latter, shouldn’t you?