Life on earth is dying, thanks to one species

The Living Planet report provides shocking proof that humans have to change our behavior

The hoolock gibbon is just one species whose numbers have crashed since 1970 and is now endangered Photo: Alamy
The hoolock gibbon is just one species whose numbers have crashed since 1970 and is now endangered Photo: Alamy

Five times in the past 440 million years, life on earth has suffered a great dying – a mass extinction eliminating between half and 97 per cent of species. In the words of the palaeontologist and conservationist Richard Leakey, such events “restructure the biosphere”. Life takes millions of years to recover – and only does so by undergoing fundamental changes, such as mammals succeeding dinosaurs.

Yesterday a report demonstrated how we are now, as Lord May, the former President of the Royal Society once put it, “on the breaking tip of a sixth great wave of extinction”. And while past ones have been blamed on intense warming or cooling of the climate, or asteroid impact, this is in danger of being the first to have been brought about by one of the very species ultimately at risk – ourselves.
The Living Planet report, produced by WWF (once called the World Wildlife Fund) in collaboration with the Zoological Society of London, has found that the number of vertebrates – mammals, birds, reptiles, amphibians and fish – on earth has fallen by more than half since 1970. It came to this conclusion, much the most alarming yet reached, by analyzing 10,380 populations of 3,038 species around the globe.

Terrestrial and marine creatures have each slumped by 39 per cent, it adds, while freshwater ones have done almost twice as badly, crashing by 76 per cent. In all, the report concludes, there are 52 per cent fewer vertebrates alive on Earth than there were when someone now in their forties was born.

Its finding meshes closely with that of another study, reported in The Telegraph in August, which concluded that the number of insects worldwide had fallen by 45 per cent since the Seventies, while human populations had almost doubled. The two reports – together forming a rounded picture of what is happening to both vertebrate and invertebrate life – depart from most previous studies by looking at what is happening to the absolute numbers of animals rather than to individual species. And – though they thus tell us less about which particular forms of life are disappearing forever – they add a valuable new dimension.

It is the number of animals in an ecosystem that decides its health and functionality. Species seem to be disappearing rather less rapidly than was once feared, since the last few members of them have often proved quite adept at hanging on, partly thanks to the establishment of reserves to protect them and partly through their own adaptability: many tropical forest species, for example, have managed to move to the trees that regenerate an area after the original ones have been felled.

And it is the health of ecosystems that matters most to us, for we depend on them, for example, to provide freshwater, protect against flooding, absorb air pollution, mitigate climate change and provide much of our food, both at land and sea. One recent report estimated that these, and other “ecosystem services”, are worth a staggering $125-$145 trillion a year to humanity.

Particular beneficiaries range from the rich inhabitants of the world’s mega cities – more than half of which are vulnerable to natural disasters such as floods and droughts – to the world’s poorest rural people, often almost entirely dependent on their natural surroundings. Not for nothing is it said that the world economy is a wholly owned subsidiary of its environment.

And yet the world’s wildlife and wild places have suffered from decades, sometimes centuries, of accelerating assault. Forty per cent of the planet’s forests, for example, have been felled since the 18th century, while 60 per cent of the globe’s “ecosystem services” have been degraded in the past half century alone. And population growth – which, far from slowing down as had been expected, may almost double human numbers this century – and ever-increasing consumption threaten those that remain.

The illegal wildlife trade wreaks horrendous damage on some species: yet another report last month showed that ivory smuggling has tripled over the past decade, while Africa’s black rhinos – poached for their horns – collapsed from 100,000 animals to 2,410 between the Sixties and Nineties. And increasing emissions of carbon dioxide make things far worse, both by warming the climate and by turning the oceans more acidic than they have been for 300 million years.

Establishing national parks and other protected areas can help. Yesterday’s report says wildlife has declined less than half as much in them, and some – such as tigers in Nepal and gorillas in the Congo – have increased markedly. But such areas must be well managed and defended and, even at best, are vulnerable to a climate change forcing species to move out. Curbing the illegal trade is also important, as governments are increasingly realizing.

In the end, though, the only solution is for the species doing the damage to tread more lightly. That does not mean living less well, only less wastefully. There are signs that it is beginning to happen. The report says that Brazil, Turkey – and even China – are on track to achieve the same standard of living as Germany in the Eighties, with smaller ecological footprints per person. Yet humanity as a whole is still consuming each year what it would take one-and-a-half planets to provide sustainably. Preventing a sixth great dying requires a rapid return to equilibrium.