Unspoiled wilderness is an increasingly rare phenomenon as humans open up more and more landscape to industrial activity and settlement, according to a new study published in the scientific journal Nature.

The report found that 70% of the world’s remaining untouched wilderness exists in just five countries, and these areas are preserved largely because they’re far from human civilization, suggesting that countries just haven’t gotten to them yet.

As a sign of that, 77% of the world’s land and 87% of the world’s oceans have so far been modified by humans.

“Numerous studies are revealing that Earth’s remaining wilderness areas are increasingly important buffers against the effects of climate change and other human impacts,” James Watson, the report’s lead author and director of the science and research initiative at the Wildlife Conservation Society, wrote in an article for Nature. “But, so far, the contribution of intact ecosystems has not been an explicit target in any international policy framework, such as the United Nations’ Strategic Plan for Biodiversity or the Paris climate agreement.”

“This must change if we are to prevent Earth’s intact ecosystems from disappearing completely,” he wrote.

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The researchers behind the report, from the University of Queensland (UQ) and the Wildlife Conservation Society (WCS), created a map to show where these landscapes and marine environments exist.

The largest remaining tracts of pristine wilderness are the vast forests and plains of Northern Canada, Alaska, and Russia.

In recent years, industrial interests have made inroads in these regions to extract fossil fuels and harvest wood.

Russia also holds most of the world’s remaining untouched marine environments.

Brazil is another member of this group because of the Amazon rainforest, the largest tropical forest in the world. Notwithstanding a brief period of environmental regulation that protected the forest in the mid to late 2000s and early 2010s, the Amazon has faced relentless destruction over the past several decades, and has shrunken by 20%. The country’s new president Jair Bolsonaro is expected to be greenlight logging, mining, and more throughout the Amazon.

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The final country holding the bulk of the world’s wilderness is Australia, which is home to vast deserts.

Zooming out, 94% of the world’s remaining wilderness exists in just 20 countries.

The research highlights the need for these countries to adopt strong environmental measures to protect these landscapes to maintain ecological balance and integrity.

It also emphasizes an inequality of natural resources around the world, a matter which will become of increasing concern as water resources become strained in the decades ahead. By 2050, more than 5 billion people are expected to be affected by water shortages.

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Untouched wilderness is crucial to generating, cleaning, and distributing water around the world, and could help to mitigate the looming water crisis.

These landscapes also clean the air and act as carbon sinks, regulate the global environment, buffer countries from natural disasters, and they’re critical refuges for countless species.

The precedent for conservation, however, is not especially promising, according to the authors.

Globally, the world has lost 1.2 million square miles to human activity between 1993 and 2009, which is around 20 times the size of Germany.

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“Wild places are facing the same extinction crisis as species. Similarly to species extinction, the erosion of the wilderness is essentially irreversible,” Watson said in the article. “Research has shown that the first impacts of industry on wilderness areas are the most damaging. And once it has been eroded, an intact ecosystem and its many values can never be fully restored.”

“Already we have lost so much,” he added. “We must grasp this opportunity to secure the wilderness before it disappears forever.”