Nearly one-third of the planet’s natural World Heritage Sites are under threat from oil, gas, and mining exploration, a new report by the World Wildlife Foundation (WWF) published Thursday has found.

According to its new report—Safeguarding Outstanding Natural Value: The Role of Institutional Investors in Protecting Natural World Heritage Sites from Extractive Activity (pdf)—the WWF says an increasing number of sites designated natural treasures, including Australia’s Great Barrier Reef, the Grand Canyon in the U.S., and the Selous Game Reserve in Tanzania, are at risk from mineral and fossil fuel extraction.

Nearly 31 percent of all the natural sites are already threatened by extractive activity, whether through commercial mining or oil and gas operations or through deals between companies and host governments that are poised to bring such activity to the sites in the near future.

And when narrowing the lens, the numbers become bigger—like in Africa, where 61 percent of vulnerable sites are subject to some form of extractive activity.

That’s a problem not just for environmental conservationists, but also for communities on the frontlines of the climate change fight. As WWF explains, extractive operations “can cause significant and permanent environmental damage both directly to landscape or water sources, and indirectly, by catalysing wide scale social and economic changes—especially in developing countries.”

“We are going to the ends of the Earth in pursuit of more resources—resources, including minerals, oil and gas, that are becoming more difficult and more expensive to extract,” said WWF-UK’s chief executive David Nussbaum. “Some of the world’s most treasured places are threatened by destructive industrial activities that imperil the very values for which they have been granted the highest level of international recognition: outstanding natural value.”