Credit: Barcroft Media via Getty Images Nearly half of the world's natural World Heritage Sites, including Yellowstone National Park, are threatened by humanity, according to a new report.

Almost half of the planet’s natural World Heritage Sites, areas designated as holding “outstanding value to humanity,” face growing threats of destruction due to human activity that has already caused lasting damage to places like Yellowstone National Park, a new report says.

The study, published Monday in the journal Biological Conservation, found more than 100 internationally protected sites around the globe are “rapidly deteriorating and are more threatened than previously thought.” Natural World Heritage Sites are selected by UNESCO for their beauty and biological importance, and include famed areas like the Congo’s Virunga National Park, the Galapagos Islands and the Everglades.

“These sites have been inscribed by the United Nations as some of the most important, beautiful places on earth,” James Watson, a professor at the University of Queensland and a senior author of the study, said in a video release. “They hold incredible numbers of species, they are the jewels of the crown when we think about nature.”

Wildlife Conservation Society Areas shown in yellow, orange and red show the amount of forest lost in natural World Heritage Sites around the globe.

The research, conducted by a team that included experts from the University of Northern British Columbia, the Wildlife Conservation Society and the International Union for the Conservation of Nature, used a metric to measure the human footprint on protected heritage areas that includes the building of roadways and destruction of forests for cattle and farming.

The report found 63 percent of natural World Heritage Sites across every continent, except Europe, saw an increased presence of humanity since the year 2000.

That pressure has already resulted in dramatic losses for some regions. Yellowstone, a hallmark of the U.S. national park system, has lost 6 percent of its forests in the past two decades, and the Waterton Glacier International Peace Park, which spans the American/Canadian border, has lost almost one-quarter of its forest area.

“These are the same as the Pantheon, the Acropolis, the pyramids,” Watson said. “Would we accept putting a car park or putting a deforestation run right in the middle of these cultural World Heritage Sites? Absolutely not. But with natural world heritage we seem to be ignoring it, we seem to be accepting that these sites aren’t really globally significant and we’re happy to lose them.”

The study is the latest in a series highlighting the destruction of natural World Heritage Sites. Last year, a UNESCO report found dozens face serious threats from climate change, and another from the World Wildlife Fund said half of all natural heritage sites were threatened by development and human expansion.

The Wildlife Conservation Society said the results should impact the priorities of the World Heritage Committee, which meets annually to monitor the status of protected areas around the globe.

“It is time for the global community to stand up and hold governments to account so that they take the conservation of natural World Heritage sites seriously,” James Allan, a lead author of the study, said in a press release. “We urge the World Heritage Committee to immediately assess the highly threatened sites we have identified. Urgent intervention is clearly needed to save these places and their outstanding natural universal values.”