Finding your way into the ethics of climate change isn’t easy. Our values; human values, grew up in little, local, tribal worlds of plenty. But climate change requires thinking on a much different scale. It’s easy to see that someone shoplifting a bottle of tequila does wrong. There’s a thief, standing red-handed right in front of you. But who does wrong in the case of climate change? Is overfilling the kettle wrong? Is a long, hot shower a sin? Is a long-haul flight for a well-deserved weekend break a kind of evil? We can make a start by thinking about climate change and the past, present, and future. We’ll begin with historical thoughts on responsibility, with reflection on the history of emissions.

Sometimes the history of the present distribution of resources matters. Suppose each day we all take an equal share of the limited amount of water which bubbles up from a common well. It turns out that I’ve been sneaking a bit more for my Jacuzzi. You might reflect on compensatory or corrective justice issues, in the thought that I should now take less water, to make up for my past excesses. Think now about the developed world’s historical use of a scarce resource, namely the carbon-absorbing properties of our planet, the Earth’s carbon sinks. The UN’s Food and Agriculture Organization categorizes countries as developed or developing. If we follow these groupings, then since 1850 the developed world is responsible for 76 per cent of carbon dioxide emissions. It has therefore used up a vastly disproportionate share of the planet’s carbon sinks. It doesn’t take much thinking about corrective justice to come to the conclusion that the developed world has a responsibility to take serious action on climate change. It was easy enough to see it in the case of the well.

Several thoughts get in the way of seeing this conclusion clearly. Maybe the most common one goes like this. Perhaps the past sometimes matters when we think about divvying up a scarce resource, but we are talking about the actions of people long dead. Maybe the activities of my parents and grandparents and so on conspired together to bring about climate change, but I didn’t do it. Saying now that I must tighten my belt because of a past injustice is nothing less than holding me responsible for the sins of my father.

We might be able to get away with that thought if it were true that our lives were entirely disconnected from the industrial activities of our forebears. However, as the philosopher Henry Shue points out, we owe the comfy lives we’ve got to all that past industrial activity. We in the west – with comparatively excellent health care and education, with nations bolstered by a sturdy infrastructure and healthy economies – are enjoying lives of plenty partly because of our histories. We’ve benefited from industrialization, and others will suffer for it as our climate changes. Do we not owe those who will suffer a few sea walls and the promise to reign in our emissions as quickly as we possibly can?