Credit: University of Washington

The modern city is a place where a vibrant array of ideas, sights, sounds and smells intermingle to spawn creativity, expression and innovation. We are drawn to the noise, the constant connectivity and the delicious food.

Simply put, society is tuned to the pulse of the city—but at what cost?

That's the question explored in a recent Science perspective piece co-authored by University of Washington researcher Peter Kahn. Its authors discuss the growing tension between an arguably necessary role urban areas play in society and the numbing, even debilitating, aspects of cities that disconnect humans from the natural world.

"Kids in large cities are growing up having never seen the stars. Can you imagine that—having never in your life walked under the vastness of the star-lit sky, and there's that feeling of awe, restoration and imaginative spark?" said Kahn, a professor in the UW's Department of Psychology and School of Environmental and Forest Sciences.

"As we build bigger cities, we're not aware how much and how fast we're undermining our connection to nature, and more wild nature—the wellspring of our existence."

Kahn, who directs the Human Interaction with Nature and Technological Systems Lab at the UW, and co-author Terry Hartig at Uppsala University in Sweden, point to research that shows the emotional and mental strain cities can have on people. Mental illnesses and mood disorders are more common in urban areas, and while many factors share the blame, reduced access to nature is a contributing cause, Kahn said.

"There's an enormous amount of disease largely tied to our removal from the natural environment," he said.

City dwellers in increasingly dense urban areas may have little or no contact with the natural world in their daily lives. That void is producing "environmental generational amnesia," a term Kahn coined and elaborates on in a recent book that describes how each generation creates a new idea of what's environmentally normal based on experiences in childhood.

If, for example, a child never crawls through the dirt looking for critters, or never cranes her neck to take in the upward expanse of an old Douglas fir tree, she may not see as an adult that forests are degraded or certain species need protection.

To take that a step further, the authors write:

"This helps to explain inaction on environmental problems; people do not feel the urgency or magnitude of problems because the experiential baseline has shifted."

Packing people into cities, then, can have serious consequences for future generations, the authors argue. There may also be such a thing as too much urban density, if the goal is to achieve access to nature alongside the advantages cities can offer.

"I'm willing to say there's a naturalness we can achieve in cities, but not at the scale we're building or at the scale we're headed with many cities," Kahn said. "There's nothing natural about a megacity."

There are steps cities can take to introduce nature into the urban core, including requiring buildings to have windows that open to allow in fresh air and natural light; incorporating more rooftop gardens and urban agriculture; and creating spaces within and around buildings to touch, see and smell native plants.

But these remedies first require an appreciation for nature in urban centers, as well as the space, resources and collective will to make these changes.

Kahn argues that it's more than just introducing nature into urban areas. People must be able to interact with these elements using more of their senses in order to experience physical and psychological benefits of nature, as well as to shift the collective baseline toward better understanding and appreciation of the natural world.

For example, looking at an office plant on the windowsill might be soothing, but having a place to sit in the grass on a lunch break and perhaps even sink one's feet into the soil are sensory experiences that can deepen a person's engagement with nature.

Thoughtfully designed cities with nature can offer both the stimulation and energy of an urban area and meaningful interaction with a psychologically restorative natural environment. The authors conclude:

"Thus, cities designed well, with nature in mind and at hand, can be understood as natural, supportive of both ecosystem integrity and public health."

More information: T. Hartig et al, Living in cities, naturally, Science (2016). Journal information: Science T. Hartig et al, Living in cities, naturally,(2016). DOI: 10.1126/science.aaf3759