flickr/ kusito

When you step out your front door and catch a breath of fresh air, how does that taste? When you look at the nearby trees, what are you really seeing? When you smell the flowers, what is that smell?

That is nature, and it feels good to be in it. This goodness of nature is more than just a mixture of senses and feelings though, it's also a growing science. In 2015, a number of insights reiterated what we already know: that we don't spend enough time outside.

These days the average American spends 93% of their life inside; 87% in buildings and 6% in vehicles. A study by the Harvard School of Public Health determined that American adults do indeed spend less time outside on average, less than 5% of each day, than they do in vehicles. As humanity gathers in cities and around screens, time spent outdoors is likely to get squeezed even further to the margins.

For evidence of why this unfortunate trend should be bucked, look no further than National Geographic's recent "This Is Your Brain on Nature" story. David Strayer, a cognitive psychologist at the University of Utah who specializes in attention, told National Geographic that spending just three days outside "is a kind of cleaning of the mental windshield that occurs when we’ve been immersed in nature long enough."

“If you can have the experience of being in the moment for two or three days, it seems to produce a difference in qualitative thinking," he said.


In the same article, Lisa Nisbet, a psychology professor at Canada’s Trent University, said that “people underestimate the happiness effect” of being outdoors.

“We don’t think of it as a way to increase happiness," she said. "We think other things will, like shopping or TV. We evolved in nature. It’s strange we’d be so disconnected.”

When considering spending time outdoors and reconnecting with nature, it helps to remember that simply being outside isn't the equivalent of being in nature. And the benefits can vary.


A study this summer found that walking on quiet, tree-lined paths encouraged people to think more positively and ruminate less than walking along busy highways and roads.

Gregory Bratman, a graduate student at the Emmett Interdisciplinary Program in Environment and Resources at Stanford University and co-author of the study, told the New York Times the results “strongly suggest that getting out into natural environments” could be an easy and almost immediate way to improve moods for those living in cities.

With more than half the world now living in urban areas—a percentage that is expected to increase to more than two-thirds by 2050—finding ways to get outside and enjoy nature will become increasingly important, especially considering how much of modern life revolves around screen time. One recent report found that children aged five to 16 spend an average of six and a half hours a day in front of a screen. Other reports put this number at over seven hours a day. Just 20 years ago in 1995, that number was closer to three hours.


As the National Wildlife Federation puts it, "this shift inside profoundly impacts the wellness of our nation’s kids:"

Childhood obesity rates have more than doubled the last 20 years; the United States has become the largest consumer of ADHD medications in the world; and pediatric prescriptions for antidepressants have risen precipitously.

Our kids are out of shape, tuned out and stressed out, because they’re missing something essential to their health and development: connection to the natural world.


One additional benefit of being in nature: it's time not spent staring at a screen.

A study published this year in the journal Frontiers in Psychology looked at four ways contact with nature seems to promote human health: air quality, physical activity, stress reduction, and social integration.

"Time spent in and around tree-lined streets, gardens, parks, and forested and agricultural lands is consistently linked to objective, long-term health outcomes," wrote Ming Kuo, associate professor of natural resources and environmental sciences at University of Illinois at Urbana-Champaign and author of the study.


In identifying the mechanisms underlying this link, Kuo came up with 21 pathways, "each of which has been empirically tied to nature and has implications for specific physical and mental health outcomes."

This Figure summarizes the state of the scientific literature on nature and health, listing (1) the “active ingredients” in nature that have been identified as having impacts on health or health antecedents; (2) physiological/psychological states, behaviors, and conditions tied to both nature and health; and (3) specific health outcomes that have been tied to nature (controlling for socioeconomic variables). Note that physical activity (in brackets) is only sometimes tied to nature; and that allergies, asthma, and eczema are sometimes positively and sometimes negatively tied to nature. DHEA: didehydroepiandrosterone; acute UTI: acute urinary tract infection; ADHD: attention deficit hyperactivity disorder; IDIC: infectious disease of the intestinal canal; MUPS: medically unexplained physical symptoms; URTI: upper respiratory tract infection.

Just looking at that chart makes me want to get outside, but you get the picture. Kuo is saying that there's empirical evidence showing if you want certain unwanted things to go away, like migraines and depression, committing to more outdoor time could make a real difference.


When it comes to the increasing number of city dwellers, Kuo thinks that urban oases like ball fields and quiet walking areas are just as "health-promoting" as larger recreation areas located outside of cities. In designing these urban greenspaces, she suggests incorporating trees, soil, and water designed in a way to "induce feelings of deep relaxation, awe, and vitality."

"Providing these green oases, especially in areas where health risks are high and landscaping is sparse, might be an inexpensive, powerful public health intervention and address persisting health inequalities," she concludes.

One potential way to increase time outdoors is to combine it with time spent commuting. The average American commute time to work is around 25 minutes each way, and spending any of that time walking, biking, jogging, and even surfing, is a way to get more out of sunk time.


There is significant room for improvement in this realm. According to the Harvard School for Public Health, "travel behavior trends in the U.S. could hardly be worse for public health." Americans only use bikes for about 1% of commutes, compared to more than 25% who do in the Netherlands. About 18% walk for transportation, a number that hasn't increased in decades.

The most recent Census found that young adults, i.e. millennials, still get to work much the same way their parents did, by car. Some 73% drive to work while only 6% of 16 to 34 year olds take public transit. And yes, just 1% bike.