Why Do We Assume that Biodiversity is Good?
The argument that human activity should be controlled to protect biodiversity often rests on an undefended assumption that biodiversity is good and human activity is bad.
You may have heard people claim that several species are facing extinction because of human activity—that humans are destroying Earth’s “biodiversity.” A recent report by the World Wildlife Fund claims that wildlife populations monitored by scientists declined an average of 70% between 1970 and 2018. Although this headline sounds like 70% of all wildlife has disappeared, what it actually means is that the populations rare or significant enough to warrant scientific attention have declined by that average (some more so, others have stayed stable or grown). In short, the claim is that certain species are at high risk of extinction, which would reduce the diversity of life—and human activity is a factor in that change.
Setting aside the question of how accurate these figures are, the thing that is often missing in this conversation is serious discussion of the question: Why is biodiversity important? Many take it for granted that, if human activity leads to a species becoming extinct, that’s a bad thing. Is it also a bad thing, therefore, that 99% of all the species that have ever existed on Earth died out before humans even existed?
The answer to both questions depends on what it means for a thing to be good or bad. Good and bad are moral concepts; they apply when an entity with a mind that thinks in abstract concepts (which, to the extent of our current knowledge, means a human being) judges something to be good or bad against his or her standard of moral value. Without human beings (or other conceptual beings, if they exist) to give things moral value, there is no good or bad.
What this means is that biodiversity is only good insofar as it is valuable to human beings. Although biodiversity is also important to the survival of animals, animals can’t think in or value abstract concepts, meaning they can’t value biodiversity or judge things to be good or bad. The importance of biodiversity to animals becomes a question of good or bad only if those animals are, in turn, valued by humans.
That leaves two essential ways in which biodiversity might be valuable: The extent to which humans depend on it for our survival and flourishing, and the extent to which it gives us other values, such as enjoyment or scientific learning. The former category applies to all human beings, the latter depends on different individuals’ personal values.
Now consider the human activity and technology accused of causing this threat to biodiversity. Are cars, planes, nickel mines, and oil rigs good or bad things? Why do we value them? For essentially the same two reasons: We depend on them to survive and flourish, and they give us other values, such as enjoyment, comfort, convenience, and the ability to produce all manner of things, from paintings and movies to telescopes and space stations.
Fundamentally, the proper standard of whether or not something is good or bad is to what extent it improves and sustains human life. If technology and industrialization enhance human life, as they have done enormously over the past three centuries, they are good things, in general. If a rare species enhances human life, it is a good thing, in general. But these are broad categories. It doesn’t mean that a car or a rare Amazonian snake is inherently valuable. It means they are valuable if and to the extent that they enhance human life. The car is valuable to the person who owns and drives it, and the snake is valuable to the person who wants to study it.
So how do you decide whether or not the impact of human activity on biodiversity (to whatever extent it has one) is a good or bad thing? By considering whether, and to what extent, it enhances human life. If there are species that human beings cannot survive without, it is in all our interests to save them. If there are species which are of interest to a small group of naturalists, but of no real consequence to anyone else, then it is down to those who value them to work to protect them. But they should do so while being respectful of the fact that other individuals value other things, and nobody has the right to force others to prioritize one person’s values over another's. The naturalist has no right to stop the lumberjack from buying up a forest, just as the lumberjack has no right to force the naturalist to sell his nature reserve.
If humanity does face a crisis of survival in the coming years, the thing that will get us through it is the same technological ingenuity that is currently being demonized for its impact on nature. Going back to a pre-industrial lifestyle will not help us—it will, in fact, reduce the length and quality of human life.