This story originally appeared on Yale Environment 360 and is part of the Climate Desk collaboration.

It is a frosty March morning in the Hoh Rainforest, deep within Olympic National Park in Washington state. The forest is full of Jurassic ferns, hanging moss, and towering spruce and cedars, but what I hope to find is an absence. I seek a spot known as the “One Square Inch of Silence”—one of the quietest places in the contiguous United States, free from chattering people, humming power lines, and the whoosh of cars.

When I find the moss-covered log surrounded by a collection of red stones marking the spot, I listen. I hear the roar of the river and maybe a waterfall. There is an occasional bird song. And nothing else. I had worried that something would ruin it—that there would already be someone there, a plane would rumble overhead, or I would hear kayakers yelling on the river nearby—but as I sit and close my eyes I can’t hear a single human sound. It feels amazing. I needed this quiet. We all do.

As the global population soars, cities and towns sprawl out, and roads stretch into even the most remote parts the world, quiet is becoming increasingly scarce. The noise of buzz saws and trucks infiltrate deep into the Amazon rainforest. The blast of ship horns ring out over the Arctic Ocean. The U.S. has become a highly developed landscape, with just a fraction of its original wilderness remaining, split up into parks and protected areas. Now, even in these refuges, cars, planes, motorboats, helicopters, and crowds contribute to the growing din.

A 2017 study by scientists at Colorado State University and the National Park Service found that human noise doubled background sounds in 63 percent of U.S. protected areas. In 21 percent of parks, human noise increased background sounds 10-fold, “surpassing levels known to interfere with human visitor experience and disrupt wildlife behavior, fitness, and community composition.”

In popular spots like Zion National Park in Utah, music blares in campsites and on trails. Hiker Erica Langston from Wilmington, North Carolina recalls the end of a Zion backcountry hike in 2017: “We converged with a popular trail and could hear the human traffic from it well before we reached it,” with people playing music or yelling to be heard over the din,” she says. “The last few miles felt more like standing in line at Disney World than walking out of the woods.”

Part of the problem is simply numbers. National parks received over 327.5 million visitors in 2019, up 9 million from the year before. Yellowstone, Rocky Mountain, Joshua Tree, Acadia: tourism is surging. While Covid-19 closures provided rangers and wildlife a temporary respite, federal parks are starting to reopen. In addition, people flocked to local parks and trails during the pandemic, raising noise levels in previously out-of-the-way spots. “If you want to go hiking on a weekend, be prepared to stand shoulder to shoulder,” says Laurabeth Roundy, a member of the Facebook group PNW Hiking with Kids who lives in Washington state.

There are still some quiet places left, however, where the sounds of humanity give way to the natural world. A 2019 study pinged both the noisiest U.S. national parks and monuments—including parts of the Grand Canyon, Arches National Park in Utah, and Rocky Mountain National Park in Colorado—and also the quietest places, which included Great Sand Dunes National Park in Colorado, Lassen Volcanic National Park in California, and El Malpais National Monument in New Mexico.

Now, a growing coalition of environmental organizations, scientists, and grassroots activists are working to protect and restore quiet places. Scientists at Colorado State University and the National Park Service are working to document where quiet has been lost and the most prominent drivers of noise in the places people go to escape it. Local activists in Hawaii and Washington state are petitioning policymakers to reduce or stop helicopter and plane flyovers near wilderness areas. And the nonprofit Quiet Parks International is turning public attention to the fragility of quiet by flagging remaining quiet areas as worthy of special protection.