A saltwater crocodile in Indonesia is shackled by a tire. (ARFA/AFP/Getty Images) (Arfa/AFP/Getty Images)

Human activity has annihilated wildlife on a scale unseen beyond mass extinction, and it has helped put humans on a potentially irreversible path toward a hot, chaotic planet stripped clean of the natural resources that enrich it, a new report has concluded.

Populations of mammals, birds, fish, reptiles and amphibians have declined by 60 percent since 1970, according to a report released Monday by the advocacy group World Wildlife Fund. The animals that remain will fight against warming oceans choked with plastic, toppled rain forests may zero out fragile species, and refuges such as coral reefs may nearly die off.

That will transform life as humanity knows it, said Carter Roberts, the chief executive of the WWF in the United States, if societies do not reverse course to protect the food, water and shelter needed for survival.

“The numbers are astonishingly bad,” Roberts told The Washington Post. “It’s death by a thousand cuts.”

The Living Planet Report, released every two years, is a biopsy of sorts for wildlife and the numerous threats to it. The group points to overexploitation of the environment — activity such as mining and deforestation — unsustainable agriculture and climate change as some of the engines driving the death of species worldwide.

The consumption and discarding of materials have entered a vicious feedback loop of destruction. For instance, in three decades nearly all seabirds will carry shards of plastic in their digestive tracts, the report found.

Toxic plastic also ends up in fish, which could hasten consequences for people who rely on fishing for industry or those who consume it. More than 4 billion people eat fish for at least some daily protein, the report said.

Slashing of biodiversity can have other dire consequences for humans.

More than a third of crops globally are partially pollinated by animals, the report found. And tens of thousands of medicinal and aromatic plants are harnessed for human use. Meanwhile, researchers have increasingly looked to natural sources for medical cures, the report said.

But the rate of animal population drop-off is 100 to 1,000 times the rate of decline before human activity was a factor, the report found, accelerating the disappearance of not just life but the ecosystems it inhabits.

That comes as the world population explodes and nature untouched by man shrinks from about a quarter of the world to a tenth by 2050, the report found, forcing animals into unsuitable and occupied environments.

“There is a connection between loss of the natural environment and human health,” Roberts said. “Where does our food come from? Where does our water come? Go to Latin America and Africa, where ecosystems are struggling,” he said, and where some governments are struggling with food scarcity and drought.

Crop failures brought on by climate change have been linked to an exodus in Central America toward the United States, for example.

“Something’s got to give,” Roberts said, “and it’s not a pretty picture.”

Tanya Steele, the WWF’s chief executive in Britain, put it more bluntly to CNN: “We are the first generation to know we are destroying our planet and the last one that can do anything about it.”

In its report, the WWF report urged governments and businesses to forge understandings on how to harvest resources without ultimately destroying them.

“In the next years, we need to urgently transition to a net carbon-neutral society and halt and reverse nature loss — through green finance and shifting to clean energy and environmentally friendly food production. In addition, we must preserve and restore enough land and ocean in a natural state to sustain all life,” WWF Director General Marco Lambertini wrote in the report.

International panels will meet in two years to discuss progress on the way forward, Lambertini noted, with optimism tinged with the understanding that there may come a time when we won’t be able to pull life back from the brink.

“We have before us a rapidly closing window for action and an unparalleled opportunity as we head into the year 2020,” he wrote.

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