Anthropocene ethics is a bit different from normal ethics. The rules change with population size . We need to learn to accept this and live by it, now that we are in an ecological emergency.
If you are a caveman living 60,000 years ago and you need to catch a flight to a very swampy New York for the annual conference on dinosaur security, it wouldn’t be an ethical problem from the point of view of climate change. Yes, the ride would be bumpy – the stone seats uncomfortable, and the worm and locust paté so-so – but there only seven of you on the flight, and there’s only one scheduled flight from London to New York every three months. So we can overlook the emissions there.
If you are making the same flight in the 1970s, as a distinguished professor of anthropology, where there are only a few billion people on the planet, then … well only a very few insightful thinkers know about climate change … and yes there is an oil crisis and air pollution … but the impact is miniscule. Only the rich world has aeroplanes and the flying population is still relatively modest – about one tenth of today’s.
But now if you fly to New York it is very different. Yours is one of five billion passenger flights each spewing out from a few hundred kg to a few tonnes of CO2, each contributing to runaway climate change, whose effects are now well known.
So the same act in one age is ok ethically because it doesn’t cause any harm. But in another age it is a crime except in the very generous, avuncular legal system we enjoy.
The same goes with food. Your Tyrannosaurus burger was actually doing us all a favour back then – no-one liked the aggressive and egoistical Tyrannosaurus Rex, so when we did manage to bring one down with a plucky ,well-aimed slingshot, it was burgers all round and double chips for the lad with the sling. No-one was too worried about the impact of that burger on emissions, deforestation in Gondwana, the dead zone in the Tethis Sea, or plastic packaging clogging up the Panthalassic Ocean. Now, as we all know, or should know, meat eating is implicated in a myriad of ills. (https://www.theguardian.com/environment/2018/may/31/avoiding-meat-and-dairy-is-single-biggest-way-to-reduce-your-impact-on-earth). Now, it is very bad news to eat meat.
That is hard for us to grasp. It riles us. How come if it was ok to eat meat when we were little, it is now no longer ok to eat meat?
We are used to ethical rules being stable, permanent. If something is wrong, then it is wrong, full stop. Like the ten commandments. We also like our ethical rules to be unconditional – if such and such is wrong, it is always wrong. But with environmental ethics, right and wrong change as a function of the population. The more crowded the planet is, the wronger it becomes to eat meat and fly.
Why is that so, when the impact of the individual act is just the same? It is something to do with the “if everyone did” test. When contemplating an act in the Anthropocene age (i.e. the age of billions of humans trampling over all other living things), there is an extra test to apply to see if an act is ethical or not. We have to ask: “What if everyone did this?”
This requires recognising that we are not just individuals (hard to do in an age of individualism). We have to acknowledge that we are also nodes in a vast network of individuals like a swarm of bees. Each thing we do influences others, so that the act of eating the meat burger is no longer just a personal rite. It is a signal to all the others that the act is ok. Giving that signal increases the probability that “everyone else” will do the act. Since by committing the act, we increase the likelihood of others committing the same act, it is incumbent on us invoke the “if everyone did test” to see if that act is ok.
Obviously in times of large population, the outcome of the “if everyone did” test is different from in times of small population. Hence under Anthropocene ethics, when using the “if everyone did” test, we have to be much more careful than we used to be.
 Not just population. Technology, too. And other things. But this is a short blog post not an essay.