Human Activities Have Cut Animal Populations In Half Since 1970

CREDIT: Shutterstock

According to a new report, the Earth has lost half its vertebrate species — mammals, birds, fish, reptiles, and amphibians — since 1970.

The latest Living Planet Report, put out by a joint research effort between the World Wildlife Fund and the Zoological Society of London, found a stunning drop of 52 percent in the population of wild animals on the planet over the last 40 years. The most catastrophic drop was among the inhabitants of freshwater ecosystems — the last stop for much of the world’s pollution from road run-off, farming, and emissions — whose numbers declined 75 percent. Oceanic and land species both dropped roughly 40 percent.

“If half the animals died in London zoo next week it would be front page news,” Ken Norris, director of science at the Zoological Society London, told the Guardian. “But that is happening in the great outdoors.”

The researchers analyzed 10,000 different animal populations encompassing 3,000 different species. The data was then used to create the Living Planet Index (LPI) to represent the situation of the globe’s 45,000 known species of vertebrates. The LPI has also been adopted by the United Nations’ Convention on Biological Diversity as an effective metric of biodiversity.


CREDIT: World Wildlife Fund & the Zoological Society of London

The Guardian noted that the worst declines of animal populations have occurred among developing, low-income nations. That’s largely because they lack the institutional protections that more advanced countries have developed for wildlife, suggesting continued economic development and better institutional design will be key to helping the developing world catch up.

But part of the poorer nations’ outsized share of the damage is because most of the damage in rich nations was done before the start of the data in 1970; as the Guardian pointed out, the last wolf in Great Britain, for instance, was shot in the 1600s. More importantly, much of the damage done by poor nations is carried out to feed economic demand in rich nations. Between 1990 and 2008, Europe imported a third of the products which — like timber, beef, and soya — often drive deforestation. The developed world is effectively “outsourcing” its share of the damage.

According to the report, about seven percent of the decline could attributed to climate change. Over one-third was due to exploitation — over-fishing, over-hunting, poaching and the like — while almost another third was due to habitat alteration and degradation. Another 13 percent could be chalked up to straightforward habitat loss.

But all of these affects fall under the broader rubric of humanity’s “ecological footprint.” That’s the metric for our total impact on the global ecosystem — the fresh water we consume, the land we alter, the natural resources we extract, the carbon we emit, the pollution we dump and the animals we wipe out. Both this report and other institutions make efforts to calculate our ecological footprint, and according to the Living Planet’s latest numbers humanity’s total footprint comes out to 1.5 earths. What this means is we’re consuming all those resources at a faster rate than they can regenerate. If the Earth was a savings account, we’d be pulling money out of it faster than the account can be replenished by interest. And eventually the principal will drop to zero.

It’s also all interconnected; land-use change can affect climate change and animal species both, then the altered climate can in turn affect the animals, and the animals’ effect on their ecosystem can in turn alter the climate again. Animals and humans both are inherent parts of the ecological fabrics they inhabit.

Efforts have been made to economically quantify the world’s “stock” of natural capital and the yearly “flow” of ecosystem services they provide. The latest numbers are $142.7 trillion and $48.7 trillion, respectively. By comparison, the flow of incomes through the global economy is currently about $71.8 trillion per year. The research suggests that by 2013 we were eliminating that stock of natural capital at a rate of about $7.3 trillion per year, and that the flow of ecosystem services would be $23 trillion higher if not for human practices like deforestation, burning fossil fuels, and the like.

And underneath all this, there is the point that these creatures and the ecologies they inhabitant have an intrinsic moral worth irrespective of the dollar sign that markets can place on them. “Wildlife is and should be useless in the same way art, music, poetry and even sports are useless,” author Richard Coniff recently wrote in the New York Times. “They connect us not just to what’s weird, different, other, but to a world where we humans do not matter nearly as much as we like to think.”

“And that should be enough.”