Scientists Warn That World’s Wilderness Areas Are Disappearing

MELBOURNE, Australia — Scientists are warning that if human beings continue to mine the world’s wildernesses for resources and convert them into cities and farms at the pace of the previous century, the planet’s few remaining wild places could disappear in decades.

Today, more than 77 percent of land on earth, excluding Antarctica, has been modified by human industry, according to a study published Wednesday in the journal Nature, up from just 15 percent a century ago.

The study, led by researchers from the University of Queensland in Australia and the Wildlife Conservation Society in New York, paints the first global picture of the threat to the world’s remaining wildernesses — and the image is bleak.

“We’re on a threshold where whole systems could collapse and the consequences of that would be catastrophic,” said James R. Allan, one of the study’s authors.

In the study, Mr. Allan and his colleagues urged the participants of a United Nations conference on biological diversity, scheduled for next month in Egypt, to protect all of the world’s remaining wilderness areas.

“We cannot afford to lose more,” he said. “We must save it in its entirety.”

The parts of the world most in need of protecting are in some of the largest and most powerful nations, the study found. More than 70 percent of wilderness areas can be found in Russia, Canada, Australia, the United States and Brazil.

Wilderness, the study’s authors said, is defined as an area not subject to direct human use.

These areas are the only places on earth that have natural levels of biodiversity, and can continue to sustain plant and animal species on an evolutionary time scale.

Moreover, these spots often act as the world’s lungs, storing carbon dioxide that would otherwise be released into the atmosphere.

“Wild areas provide a lot of life support systems for the planet. We’d lose those benefits and those ecosystems services, and the cost of having to replace that would be immense,” Mr. Allan said.

In 2016, the scientists mapped the world’s terrestrial wildernesses. This year, they did the same for the world’s oceans.

More of the oceans have been affected by human industry — including oil exploration, shipping and commercial fishing — than have the world’s land mass, the study found.

According to the study, “87 percent of the ocean has been modified by the direct effects of human activities.”

“This astonishing expansion of the aggressive human footprint is happening everywhere,” said William Laurance, a professor of environmental science at James Cook University in Cairns, Australia, who was not involved in the study.

Dr. Laurance said that while he “wholeheartedly” agreed with the researchers’ message to policy experts, even more aggressive action was needed to stop global resource extraction and industrial expansion.

He warned that developing countries like Brazil and China are eager to catch up with more industrialized nations. Each step those countries take has a compounding effect on the environment: Developing mines also means building roads and refineries.

Healthy ecosystems are crucial in their own right for biodiversity and mitigating climate change, but more importantly, said the researchers, they are home for hundreds of millions of indigenous people, who rely on the wilderness to survive and thrive.