The world, if the biologists' projections turn out to be correct, will soon begin to revert to the Bible's fourth day of creation. There will be grass and "herb-yielding seed" and "the fruit tree yielding fruit". But "the moving creature that hath life", the "fowl that may fly above the Earth", or the "great whales, and every living creature that moveth" may one day be almost unknown to us.
Last week, the journal Nature published a report suggesting that, by 2050, around a quarter of the world's animal and plant species could die out as a result of global warming. To these we must add the millions threatened by farming, logging, hunting, fishing and introduced species. The future is beginning to look a little lonely.
Does it matter? To most of those who govern us, plainly not. To most of the rest of us, the answer seems to be yes, but we are not quite sure why. We have little difficulty in recognising the importance of other environmental issues. Climate change causes droughts and floods, ozone depletion gives us skin cancer, diesel pollution damages our lungs. But, while most people feel that purging the world of its diversity of animals and plants is somehow wrong, the feeling precedes a rational explanation. For the past 30 years, the conservation movement has been trying to provide one. Its efforts have, for the most part, failed.
The problem conservationists face is this: that by comparison to almost all other global issues, our concerns about biodiversity seem effete and self-indulgent. If we are presented with a choice between growing food to avert starvation and protecting an obscure forest frog, the frog loses every time. If climate change is going to make life impossible for hundreds of millions of human beings, who cares about what it might do to Boyd's forest dragon?
So they have sought to confront utilitarianism with utilitarianism. If the rainforests are destroyed, they argue, we may never find the cure for cancer. If the wild relatives of our crop plants die out, we might lose the genes that could be used to breed new pest-resistant strains. Many of the world's indigenous people depend upon a wide range of species for their survival. An impoverished environment is likely to be less stable, and so less productive, than a diverse one.
All this may be true, but it doesn't solve the problem of justification. Most of us don't need biodiversity to survive. The farmers who produce our food try to keep the ecosystem as impoverished as possible. A utilitarian approach, long favoured by communists as well as capitalists, would integrate indigenous people into the mainstream economy, drag almost all the population of the countryside out of its "rural idiocy", and turn every productive acre of the Earth over to crops.
Utilitarianism also suggests that the value of biodiversity is exhausted once it ceases to be useful to us. When a rainforest has been screened for pharmaceutical compounds, it offers, according to this doctrine, no further benefits. We can grow the useful species in plantations, or produce the compounds they contain in the lab, and junk the rest. By arguing for biodiversity on the grounds of human need, in other words, conservationists play into the hands of their enemies.
The lovers of fine art or rare books don't feel the need to set this trap for themselves. They never suggest that money and effort should be spent on restoring old masters because one day someone might want to eat them. They can defend the things they value, even while accepting that there may be a conflict between their protection and other social needs. We could solve London's housing crisis by levelling its historic buildings, grubbing up the parks and building high-rise homes in their place. But the aesthetes can confidently assert that the lives of its people would scarcely be improved by those means.
The special problem the conservationists of nature face is that in many parts of the world their cause has been used as an excuse for the maintenance of a colonial model of exclusion. Nothing has done more harm to conservation than the work of people like Richard Leakey, Joy Adamson and Diane Fossey. To white tourists, who now have more or less exclusive access to the places they helped to protect, these people are heroes. To local people they are villains, and the wildlife they protected is perceived as a threat. If every time a public gallery was built, thousands of us were kicked out of our homes to make way for it, then told we could enter only by paying the equivalent of our annual income, we would feel the same way about art.
This legacy of exclusion makes conservation look harder to justify on the grounds of aesthetics. But it seems to me that this is the only sensible argument that can be made. It is surely sufficient to say that wildlife should be preserved because it is wonderful.
But, somehow, most conservationists can't quite bring themselves to do so. Even those who admit that they want to protect it because they love it can't leave it at that, but insist on seeking some higher justification. It used to be God; now they claim to be acting for "the sake of the planet" or "the ecosystem" or "the future".
As far as the planet is concerned, it is not concerned. It is a lump of rock. It is inhabited by clumps of self-replicating molecules we call lifeforms, whose purpose is to reverse entropy for as long as possible, by capturing energy from the sun or other lifeforms. The ecosystem is simply the flow of captured energy between these lifeforms. It has no values, no wishes, no demands. It neither offers nor recognises cruelty and kindness.
Like other lifeforms, we exist only to replicate ourselves. We have become so complex only because that enables us to steal more energy. One day, natural selection will shake us off the planet. Our works won't even be forgotten. There will be nothing capable of remembering.
But a curious component of our complexity is that, in common with other complex forms, we have evolved a capacity for suffering. We suffer when the world becomes a less pleasant and fascinating place. We suffer because we perceive the suffering of others.
It appears to me that the only higher purpose we could possibly possess is to seek to relieve suffering: our own and that of other people and other animals. This is surely sufficient cause for any project we might attempt. It is sufficient cause for the protection of fine art or rare books. It is sufficient cause for the protection of rare wildlife.
Biodiversity, in other words, matters because it matters. If we are to protect wildlife, we must do it for ourselves. We need not pretend that anything else is bidding us to do so. We need not pretend that anyone depends upon the king protea or the golden toad or the silky sifaka for their survival. But we can say that, as far as we are concerned, the world would be a poorer place without them.
