Journalist Florence Williams looks at the scientific research about the innumerable benefits that time outdoors brings us.

According to the World Health Organization, 27 percent of Europeans (approximately 83 million people) experienced at least one mental health disorder in 2017. It’s no secret that the problem is not limited to Europe. Depression, anxiety, and stress continue to affect people across the globe at alarming rates.

Technological advancements pave the way for new communication and innovation, but they are simultaneously proven to decrease the human capacity for empathy, focus, and connection. Children in America and Britain spend up to seven hours a day in front of a screen (not including the school day), cutting their time spent outdoors in half when compared to their parents as children.

Not only are people choosing to spend their time differently than previous generations, but cities are also being planned and structured differently. For example, prior to World War II, most hospitals were intentionally placed near or in a park. However, after the rise of the Technological Revolution and the close of the Second World War, proximity to nature was no longer an essential consideration for the building of hospitals. John Muir might have noted this as part of the shift toward a mechanized view of humanity, where efficiency takes precedence over other aspects of human well being.  

We must ask ourselves how new human habits negatively impact the human experience and examine if nature has the capacity to override these outcomes. A growing body of research strongly suggests the tremendous benefits of nature and the detriments of not immersing oneself in it.

In 2008, the World Health Organization noted that, for the first time ever, more people lived in urban environments than in rural ones. But having evolved in nature, what are we missing by not being immersed in it?

Japanese research supports the biophilia hypothesis, an evolutionary adaptation that understands humans as innately connected to other living organisms. The effect of this hypothesis supports the positive physiological and emotional response of humans to nature. For example, Japanese researchers Miyazaki and Lee have tested hundreds of subjects and various data points, finding that “forest bathing” produces positive neurological changes, as well as boosts immune cells.

According to cognitive psychologist David Strayer, urban environments are not suitable for optimal brain functioning. The three main brain networks are the Executive, which controls intellectual and task performance; Spatial, which orients humans; and Default, which produces empathy and creativity and allows the Executive network to rest in order to rebound to peak performance. Nature supports the Default network, thereby repairing our ability to stay focused, and to think clearly and creatively.

To set ourselves up for success, we must consider the fact that our physiology is evolutionarily wired to respond differently to various environments. Miyazaki suggests that, “During everyday life, a feeling of comfort can be achieved if our rhythms are synchronized with those of the environment.”

The effects of nature can be defined in both the presence and absence of certain things. In our post-modern society, it is not easy to escape electronic hum, transportation, and other people. Alternatively, nature—even in small doses—provides a retreat from the societal norm, as well as an immersion into something different. 

The physiological benefits of nature begin with our sense of smell. Scents tap into the primal portion of the human brain, which activates fight-or-flight responses, as well as the hippocampus, which stores memories and regulates emotion. We can think of the nose as “a direct pathway to the brain.” Far fewer pollutants in natural environments as opposed to urban ones is a contributing factor in why we are more cognitively aware in nature. The presence of therapeutic smells—aromatherapy—is scientifically thought to improve both mood and functioning.

Anthrophone refers to the soundscape created by human activities. Due to the rise of cars, planes, deforestation and urban development, anthrophone noises double nearly every thirty years. Sound Engineer Gordon Hempton found less than a dozen places in the continental U.S. where one cannot hear any human-made noise for at least fifteen minutes at dawn. Sound enters through the ear, reverberates against the eardrum, and is picked up by the nervous system, which sends signals to the brain for processing. The increase in anthrophone noise is often interpreted by our brains as danger, providing a feasible explanation for the increase of chronic stress. Conversely, the sounds of birds, creeks, and other natural noise are interpreted by our brains as relaxing and rejuvenating. Biobehavioral health psychologist Joshua Smyth recommends twenty minutes a day in a quiet place as an acute stress intervention tactic.

Qualitative research points to the positive effects of light and landscape views from hospital windows. Similar to sound, certain visual patterns communicate stress and others, relaxation. According to research by Richard Taylor, a nanoparticle physicist, specific fractal patterns found in the natural environment (and reproduced in certain pieces of art and artificial environments) engage the frontal lobe to produce a state of relaxation, as well as engaging the parahippocampus to regulate emotions. His research also finds that one does not have to meditate on these patterns to make them effective. Environmental exposure via a walk through a fractal-patterned hall is enough to achieve the desired outcomes. The “fluent visual processing” that occurs while processing an abundance of eye-pleasing fractal patterns explains why we feel most at peace in nature—even if we don’t necessarily like the outdoors.

According to research by Finnish economist and ecologist Liisa Tyrväinen, natural landscapes can be monetarily quantified. Of course, nature views increase property values, but the health benefits of spending five hours in nature per month are proven to improve mood and health, thereby decreasing healthcare expenses. The cost-benefit savings of natural preservation are high. This discussion has transformed the topic of saving the planet from humans to saving the planet for humans.

In Scotland, however, researcher Richard Mitchell has examined the ramifications of the visible socio-economic disparity related to access to nature. And the statistics are shocking. In some Glasgow neighborhoods life expectancy for a man is 54, while only 12 miles away in more rural areas, it is 82. But perhaps most noteworthy is Mitchell’s research in England. His findings clearly indicate that “income-related health disparities were greatest in areas with the least green. Here, poor people were twice as likely to die as their rich neighbors.” The trend decreases in greener areas, where poor populations “catch up” to the mortality ages of the rich.

The opportunity for exercise and the proven propensity of nature to decrease human stress may both play a contributing role in these disparities. However, the message is clear: Nature must be made accessible to everyone. Local and civic responsibility are vital to protect and maintain green spaces. More nature-based social programs for at-risk communities would allow a holistic approach to mental and stress-related illnesses. This will drastically reduce the cost-burden of hospitalizations and treatment.

Muir, Emerson, and Thoreau all write of the Transcendental experience of nature. Emerson writes, “Standing on the bare ground, my head bathed by the blithe air and uplifted into infinite space, all mean egotism vanishes. I become a transparent eyeball; I am nothing.” Nature places us in a position to realize that we are a part of something greater than ourselves. This feeling of awe can evoke wonder, humility, and trepidation. But scientists and psychologists indicate that awe can be even more powerful than happiness.

Awe reinforces social connections, which in turn lower inflammation, which boosts the immune system. Furthermore, awe promotes curiosity and generosity. In a study measuring reactions to various emotions, participants experiencing awe shared resources at a rate of 40 percent more than their counterparts.

Lee Kuan Yew is credited with his vision of the Garden City, which has done much to develop Singapore into a green oasis. Stunning towers and careful botanics are all a part of the cityscape designed to be a true Biolithic space. Metropolises across the world are taking a cue from Singapore and becoming more dedicated to planting trees and increasing accessible greenspace for their residents.

While Yew’s vision of the Garden City is better than a concrete one, it still falls short in comparison to the natural environment. Urban nature serves us best when it’s allowed to be wild, inspiring awe and cultivating connection. City planners must develop a “nature ethic,” committed to promoting greenery in all neighborhoods. It’s unrealistic to think that humanity will ever emigrate from urban areas in mass quantities, so we must do what we can to make our urban environments as healthy and happy as we can.

Whether you have the ability to access nature on a small-scale, a more regular pattern of at least five hours per month, or intensely with immersive wilderness trips, you will reap the benefits.

The good news for urbanites is that even small doses of nature offer near-immediate benefits. For example, walking under trees reduces cortisol levels at higher rates than walking down a busy street. For better results and an increased capacity for rumination and concentration, ditch your cell phone. Studies show that people who walk while talking on their cell phones scored an average of 50 points less on a memory test than those who did not use a phone at all along the same routes.

For those struggling with mental health disorders, five or more hours a month spent in nature will be more beneficial. At least 30 minutes a few times every week will set you up for success. Of course, by increasing the dosage you will increase the benefits.

Those suffering from PTSD, and children with ADHD, are proven to benefit from longer doses of immersion in the natural environment. For example, veterans who go on wilderness trips experience a 9 to 19 percent improvement in mental health. Furthermore, veterans immersed in similar wilderness experiences reported flashback decreases of up to 40 percent. Children with attention disorders may find themselves better suited to the freedom of the outdoors. And while their prefrontal cortex is still developing, it is imperative for all children to go outside so they can reap the benefits—manual dexterity and teamwork among them.

Whether you have 30 minutes a week or 72 hours a month, the best way to apply the research is to get outside. You won’t regret it.