There are four existential threats to our species.
The best known and most talked about, although still stubbornly disputed, is global warming. It is probably too late to head it off, even if we really knew how. It would help if people could agree it was a threat to life and not see the very idea as a threat to their profits, but there we are. We have absolutely no idea what the consequences will be but they are unlikely to be wholesome.
The second, of which I confess I have only just become aware, is that we are already in the middle of a mass extinction of animal life on the planet, comparable in scale and perhaps effect to the extinction of the dinosaurs. This has nothing to do with global warming as such, although our sheer numbers affect both, for it is simply an effect of the pressure which human life exerts on the rest of the biosphere. Animal species for example are being lost at an alarming rate as they are pushed to the margins of survival. The figure which stands out for me is that we humans and our domestic animals now account for over 95% of animals by mass on the planet. There is no “wild”. See for example this article. Can we continue to flourish without it? Probably, for a while but maybe not indefinitely.
The third is the threat of our own cleverness. Sooner or later and even though it has long been the stuff of science fiction our creations will get the better of us. We are not clever enough to foresee all the consequences of all our actions. We will create a bio-catastrophe through genetic engineering or a machine we cannot control or software than deems us redundant or some other technological oversight – provided of course we don’t just blow ourselves up.
The fourth has always been with us and come close to succeeding in wiping us out on several occasions – nature itself. We think we are in control, but a major volcanic event, for example, could bring us to our knees. Or a change in climate causing drought or famine. Or a naturally occurring disease might arise which we could not defeat in time – it is less than a hundred years since flu claimed more lives than a World War, for example. A compilation, in other words, of the old horsemen.
In my lifetime the human population of the earth has roughly trebled. There are a lot of us and it would take something extraordinary to get all of us. Fewer humans would paradoxically relieve some of the pressures from some of these four causes, perhaps even making the survival of the species more likely. But it would not be a pretty process. Imagine going back in short order even to the global population level of the middle of the twentieth century, or in other words wiping out two thirds – two out of three! – of the people on the planet.
It would be daft to claim that a stronger sense of values will make all these threats go away. A species which thought about what really mattered rather than, or even as well as, how to make a quick profit might have a better chance, though. And they might both live better and behave with more dignity when disaster arrived.