The number of wild animals on Earth has halved in the past 40 years, according to a new analysis. Creatures across land, rivers and the seas are being decimated as humans kill them for food in unsustainable numbers, while polluting or destroying their habitats, the research by scientists at WWF and the Zoological Society of London found, says an article in the Guardian.
“If half the animals died in London zoo next week it would be front page news,” said Prof. Ken Norris, ZSL’s director of science. “But that is happening in the great outdoors. This damage is not inevitable but a consequence of the way we choose to live.”
One half of the animal population is lost and knowing this is driven by human consumption, it is clearly “a call to arms and we must act now,” said Mike Barratt, director of science and policy at World Wildlife Fund (WWF).
Declining Trend
The steep decline of animal, fish and bird numbers was calculated by analyzing 10,000 different populations, covering 3,000 species in total. This data was then, for the first time, used to create a representative “Living Planet Index” (LPI), reflecting the state of all 45,000 known vertebrates.
“We have all heard of the FTSE 100 index, but we have missed the ultimate indicator, the falling trend of species and ecosystems in the world,” said Prof. Jonathan Baillie, ZSL’s director of conservation. “If we get [our response] right, we will have a safe and sustainable way of life for the future,” he said.
If not, he added, the overuse of resources would ultimately lead to conflicts. He said the LPI was an extremely robust indicator and had been adopted by UN’s internationally-agreed Convention on Biological Diversity as key insight into biodiversity.
A second index in the new Living Planet report calculates humanity’s “ecological footprint,” i.e. the scale at which it is using up natural resources. Currently, the global population is cutting down trees faster than they re-grow, catching fish faster than the oceans can restock, pumping water from rivers and aquifers faster than rainfall can replenish them and emitting more climate-warming carbon dioxide than oceans and forests can absorb.
The report concludes that today’s average global rate of consumption would need 1.5 planet Earths to sustain it. But four planets would be required to sustain US levels of consumption, or 2.5 Earths to match UK consumption levels.
Freshwater Systems
The fastest decline among the animal populations was found in freshwater ecosystems, where numbers have plummeted by 75% since 1970. “Rivers are the bottom of the system,” said Dave Tickner, WWF’s chief freshwater adviser. “Whatever happens on the land, it all ends up in the rivers.” For example, he said, tens of billions of tons of effluent are dumped in the Ganges in India every year.
As well as pollution, dams and the increasing abstraction of water damage freshwater systems. There are more than 45,000 major dams – 15m or higher – around the world. “These slice rivers up into a thousand pieces,” Tickner said, preventing the healthy flow of water.
