The United States’ National Park Service estimates that protected public lands in the US are worth about $92 billion, but that figure is actually likely too low.

In fact, national parks’ unique offerings have such a positive effect on mental health that they save trillions of dollars in healthcare costs — but for the US, those benefits may be in danger.

National parks like Yosemite and Grand Teton save healthcare systems around the world about $6 trillion dollars, according to a new paper. And that’s a “conservative” estimate, according to Ralf Buckley, chair of ecotourism research at Australia’s Griffith University.

The massive savings stem from a “de-stressing” effect that comes from spending prolonged time in nature, Buckley tells Inverse.

The article was published this week in the journal Nature Communications.

National parks bring big benefits

The new estimate jibes with a wave of research hinting at the mental health benefits of natural surroundings — particularly green and blue spaces. Even in crowded cities, green spaces may improve mental health, says Buckley — but they might not be quite so good for you.

“We compared park visits and non-park green-space, which of course is one of the more common workplace wellness approaches,” Buckley tells Inverse. “We found that both had positive effects, but the effect of parks was several times larger.”

A view of Glacier National Park in Montana. Shutterstock

What is it about national parks that makes them so good for you? One theory is that they’re simply more natural than other types of parks. In most cases, parks like Glacier National Park in Montana or the Peak District in England are relatively devoid of wifi signal and far from urban environments.

But they may not stay that way for much longer. As national parks begin to change, striking a balance between improving park facilities without robbing them of their restorative qualities is a top priority, experts say.

Do national parks need modernized?

In October this year, the “Made in America” Outdoor Recreation Advisory Committee issued a letter to the United States Department of the Interior suggesting that they begin to “modernize” some aspects of the country’s national parks. The recommendations included expanding wifi access, allowing private businesses like food trucks to operate inside park grounds, and even letting Amazon make deliveries within them.

In November, the committee was terminated and no actions have been taken based on their suggestions. But as more and more people visit the parks, it could be a sign of things to come.

In 2018, there were 318.2 million visits to national parks in the US — the third highest number since 1904. But the increased traffic has also strained resources. For example, between June and September 2017, the road to Cadillac Mountain summit in Acadia National Park was closed 49 times due to “gridlock congestion and public safety concerns,” according to the National Park Service.

Overcrowding at Acadia National Park in Maine. Rhonda Wanser/ National Park Service

Edward Truch, an information systems professor at Lancaster University’s Management School tells Inverse that there’s pressure on parks to “Disney-fy” to keep people entertained and coming back for more.

“One of the challenges the national parks have is to attract younger visitors. To do that they bring in zip wires and things that ultimately cause damage to the landscape,” says Truch.

Adding amenities that contribute to “Disney-fication” could detract from the powerful effects of parks on mental health, says Aaron Schwartz, a graduate student at the University of Vermont. Schwartz studies how green spaces impact mental health. In a paper published earlier this year, Schartz and his colleagues showed that people tend to be happier in larger, regional parks than they are in neighborhood parks or civic plazas.

The regional parks were greener and further from urban environments, which could have given them an edge over traditional urban parks, he says. Other studies have also suggested that tree canopy exposure is associated with lower psychological distress compared to exposure to other types of green spaces, like grass fields or low-lying shrubbery.

If a park is modernized in a way that reduces green space, that could soften their health benefits.

“Adding a variety of modern amenities or wifi could detract from the experience that people are seeking when they visit these spaces,” Schwartz says. “There’s some evidence that spending time in nature allows you to reduce stress or get your attention back after spending all day on the computer. If you go into nature and go on your phone you lose that opportunity.”

Buckley agrees that taking away from the “real world” experience of being in a natural park would “probably reduce mental health benefits.” But both he and Schwartz note that there could be ways to modernize these parks and preserve the unique benefits they offer.

Modernizing national parks, the responsible way

Not all modernization may be bad. Accessibility is a major issue for many national parks. There are plenty of medical, economic, or mobility concerns that deter people from spending time in them — and from reaping their mental health benefits.

"What we’re suggesting is the use of smart technologies which are almost invisible."

Wifi in a park could actually help offset some of these concerns, because it can provide “a safety backup and information source,” says Buckley.

Another possible strategy is to create “Smart Parks,” an idea Truch describes in a 2018 report.

“What we’re suggesting is the use of smart technologies which are almost invisible, and yet they can also make a visit to a park far more exciting, fun, education and healthier,” Truch says.

“For example, if people suffer from particular health problems like asthma, then you could send them a message saying, ‘If you are asthmatic, it’s best not to go into this particular valley today.’”

Ultimately, these strategies could allow even more people to benefit from them, Truch says.

“I think there’s a balance to be struck between making those places accessible, but also maintaining the features that make them beneficial for us,” he says.