I recently moved from a place that had a backyard that looks like this,
to one that looked like this.
There are a lot of great things about cities,
but access to nature isn't always one of them.
Many days I felt like the closest thing I got to nature
was looking at grainy cat videos on YouTube.
(Laughter)
I'm sure some of you can relate.
Sometimes you don't realize how important something is to you until you lose it.
I wasn't like Woody Allen who once said:
"I love nature, I just don't want any of it on me."
(Laughter)
I wanted it on me, and I missed it.
When I moved for my husband's job from Boulder, Colorado, to Washington DC,
I wasn't too happy about it.
But I was still surprised by how swiftly my sense of well-being plummeted.
I got depressed, I was anxious, I felt irritable.
My brain felt sluggish and dull.
I had to get used to new sounds, like overhead aircraft all the time,
helicopters and those ubiquitous leaf blowers that I hear all the time.
But fortunately, shortly after I moved,
I was given a dream assignment by Outside Magazine
to go visit the national forests of Japan
to write about an obscure practice called "shinrin yoku," or forest bathing.
This essentially involves just being on a trail:
walking, sometimes sitting, sometimes just lying on a boulder
and letting nature pour into all of your senses.
So perhaps imagine with me for a minute what this might be like.
You're sitting there and you're hearing the birds and the crickets.
You're smelling the rich loamy earth and maybe the scent of fresh pine trees.
You can feel the breeze on your cheek and the moss under your feet.
How do you think this makes you feel?
Well, scientists in Japan wanted to answer precisely that question.
And so in a series of experiments they sent 84 stressed-out college students
to go hang out for 30 minutes in these forests
and then also to go hang out on a city street.
And here's what they found -
this is me doing one of the experiments:
A 16% drop in the stress hormone cortisol.
A 2% drop in blood pressure.
A 4% drop in heart rate.
This is among the forest visitors.
None of that happened in the people who went to the city.
And the people who went to the forest also reported less anxiety and better moods,
whereas the opposite happened in the people who went to the city.
So, nature has superpowers for us.
And there's even a dose effect:
it looks like the more time you spend in nature, better things can happen.
So in Japan they sent some of these students,
or some other people, some volunteers,
to go spend three days at a forest lodge.
And they found a 40% increase
in an immune cell called natural killer cells
It's critical to the immune system.
When they went to vacation in the city that didn't happen.
So it's not just a vacation effect, there's something about nature.
I became so intrigued by this story and by this science
that I took another assignment from National Geographic.
And this one sent me to a handful of other countries around the world
studying this topic to improve the health of citizens,
sometimes even going as far as to recommend nature as medicine.
So in Japan, as we just saw, there are these forests therapy trails.
They have 48 of them.
Korea will have 37 healing forests by next year.
These are entire forests.
And to go along with that, they're training 500 healing rangers
to lead programs for everyone, from digital addicts to school bullies.
The school bullies, by the way,
take a train called "the happy train" from the city to the forest.
(Laughter)
Also programs for firefighters with PTSD,
and even prenatal women and cancer patients,
I mean, it just goes on and on what they're doing there.
I also went to Finland.
And Finland has gone so far as to recommend, it's a very precise country,
they recommended a specific dosage of nature to ward off depression.
And what they recommend, take note:
five hours a month of being in nature or a little over an hour a week.
Now, Finland is really fortunate because it's a country covered with forests
and coastlines and parks.
But many parts of the world are not so lucky.
Already, over half of us in the world live in cities.
And by 2050 that proportion will be 70%.
So making cities green and livable
will be one of the greatest challenges of our century.
How can cities and civic institutions make spaces of awe and restoration?
The city of Wellington, New Zealand, has made a space of awe
by designating and signposting a snorkel trail very close to downtown,
where you can just jump in the water, swim around,
and she things like octopus, and butterfish and seahorses.
How cool is that?
Seattle offers low-tide walks
where children love to see sunstars and moon snails.
In Singapore there are parks interspersed with public housing projects
so that people from all over the city have access to nature.
And the city also encourages architects and developers
to incorporate butterfly-loving vertical gardens
into corporate and residential towers.
When my cab driver dropped me off at this hotel,
he said how handy it was I was staying here,
because I could just wake up in the morning and start grazing.
(Laughter)
The University of California at Berkeley has created a space of awe
by protecting one of the tallest hardwood groves in North America.
And this is great because the students can go here to recover from stress
and psychologists at the University can study it happening.
So one way to do this
is they sent students go look up at this grove of trees for one minute
and they also sent another group
to look up at a building on campus for one minute.
And in a clever bit of trickery,
a research assistant dropped a box of pens in front of each subject.
So guess who helped her and picked up more pens:
people in the forest or the people looking at the building?
If you guessed the forest, you are correct.
And it only took one minute of them feeling awe
to behave in a more generous way.
So it looks like time outside in nature can also make us more creative.
When we spend time outside in beautiful places,
a part of our brain called the subgenual prefrontal cortex quiets down.
And this is a part of the brain
that's associated with negative self-involved thoughts.
A researcher at Stanford made the nature connection
when he sent a group of subjects to go walk
in a beautiful park in Palo Alto for 90 minutes,
and he sent another group to go walk in a city street,
and then he imaged their brains.
And it was only the people who walked in the park
who experienced this beneficial change.
So nature can be so helpful to us in so many ways.
It can also make us creative in small doses.
For example, here's Facebook,
and hi-tech communities all over are now figuring out
that if they incorporate green roofs and trails into their very structures,
that this can benefit their business.
We've known this for a long time.
Everyone from Aristotle to Beethoven,
to Darwin, the Brontë sisters, Wordsworth, Einstein,
the list goes on and on,
so many people attribute walking in these beautiful spaces
to being critical to their creative process.
What happens, though, when we spend even more time in nature,
as far as our brains and our psychology?
We know that physiological changes happen,
which we saw with the natural killer cells.
But what happens on a more psychological level?
This was something I was fascinated to actually witness,
when I met a woman named Tania Herrera.
She had just returned from two tours of Iraq,
and she'd been badly injured in rocket grenade fire and also by a car bomb.
She'd experienced a bad concussion, she'd lost the use of one of her arms.
She experienced seizures, anxiety, depression.
She had trouble performing simple tasks and even reading.
She never wanted to leave her house,
because she felt like she was a prisoner in her own body.
But when she'd been young, she'd participated in a program
to take inner-city kids out into nature.
And she'd remembered that that had given her some comfort.
So she signed up for a six-day river trip down the Salmon River in Idaho.
She and her other fellow warriors on this trip paddled and swam,
and slept under stars and talked in the camp, around the campfire.
And I had the privilege of watching them emerge from cocoons of sadness
to full-bodied full-sensory survivors helping each other,
relishing their new friendships and the possibilities ahead.
She said to me:
"When I'm home I feel overwhelmed, there's nothing to brace on,
and I'm overwhelmed by bad thoughts and feelings.
When I'm out here life is simple, there's something to brace on,
there are good thoughts, there is balance."
Wilderness advocate John Muir understood the power of wilderness
to help heal our psyches.
He wrote:
"Between every two pine trees, there is a door leading to a new way of life."
There is a simple recipe to improve the quality and meaning of our days.
And it's to open Muir's door.
Go outside, go often.
Thank you.
(Applause)