Green Space and CO2 & the City Dark

  • The Milky Way above an AZ observatory. (Credit: Wicked Delicate Films, LLC.)

Scientists know a lot about how natural places process carbon dioxide.  But there hasn’t been a lot of research into what happens throughout the year in the green spaces in cities and suburbs.

Emily Peters is an author of a paper out this week in the Journal of Geophysical Research.  She’s been looking at how plants and trees in one suburban neighborhood take in carbon dioxide during the year… and how they offset the carbon dioxide people in the neighborhood emit – by say, driving their cars.

“In the summer we found the uptake of carbon dioxide from the vegetation is enough to offset fossil fuel emissions – just in the summer.”

She says evergreen and leafy trees took in more CO2 during the middle of the summer. Lawns did the best job of taking in CO2 during the spring and fall.  But Peters says those plants did NOT balance out the total amount of carbon dioxide released in the suburban neighborhood by burning fossil fuels over the year. 

If you're wondering: do certain species of trees do a better job than others?

"That is the question everybody wants answered – we can’t go out with this study and tell city foresters they should plant more of this kind of tree vs. this kind of tree."

 (music bump)

This is the Environment Report.

When was the last time you were someplace so dark that you could look up at the night sky and actually see the stars? Not just a handful, but hundreds or thousands?

“The Milky Way when it rises here looks like a thunderstorm coming toward you. And you think, oh my god, it’s going to cloud over and it’s not, it’s the Milky Way rising, it’s the edge of our galaxy coming up.”

That’s a scene from a new documentary. It’s called The City Dark and it airs tonight on PBS stations (check your local listings).

The film takes a look at our love affair with artificial light – and why humans and wildlife need the night sky.  Ian Cheney directed and produced The City Dark and he joins me now.  Ian, you grew up in rural Maine – and in fact we’re talking to you from your parents’ house in Maine right now, but you’ve been working in New York City – and obviously, those are two big extremes. Why did you want to make this film?

Cheney: Well, when I moved to New York City, one of the first things I realized was that I was missing the night sky, and that launched me on a journey to explore this broader topic of light pollution and how artificial light affects our world.

RW: So what do you think we lose when we’re in cities or suburbs with bright street lights when we can’t see the sky?

Cheney: Well, it probably varies person by person but a lot of the things I came to feel and a lot of the things I heard from the people I interviewed involved a loss of a sense of perspective, a sense of place in the universe, a sense of connection to the cosmos, the stars beyond the everyday world in which we live that provides all sorts of inspiration.

RW: I have to tell you your photography of the night sky in this film is so beautiful.  What kind of challenges did you have shooting the footage?

Cheney: Well, the word photography of course means writing with light. So the idea of making a film in the dark was challenging from the beginning, especially on a budget with small cameras. So we used a lot of time lapse photography in the film, using regular SLR still cameras, not video cameras, to shoot still images of the night sky in sequence. We would shoot hundreds of images of stars over the course of the night, then string them together in time lapse imagery so you can watch the stars rise up over a mountain, or in many cases, watch city lights twinkle throughout the night as a few stars pop up as best they can.

RW: Ian Cheney is the director and producer of The City Dark. It airs tonight on PBS stations (check your local listings). Thank you so much!

Cheney: Thank you!

RW: Michigan has one of only six International Dark Sky Parks in the country.  That’s a designation for a place with an exceptional view of the night sky. Ours is The Headlands, in the northwest Lower Peninsula about two miles west of Mackinac City. 

That’s the Environment Report for today. I’m Rebecca Williams.