Take a walk around Boston, especially along the Tremont Street edge of the Common.  That’s where most of the sculptures in the environmental art exhibit, “Cool Globes,” have landed. Some of the globes have been commissioned from Boston artists such as Nancy Schön, who fashioned the ducklings in the Public Garden and the tortoise and hare on Copley Square. The other globes have traveled to 14 cities as part of an exhibit intended to highlight climate change and encourage viewers to find solutions to our heating planet.

The artists were given plain white five-foot spheres. Then they applied paint, objects—all kinds of mixed media—to fashion one-of-a-kind pieces.

It’s a welcome event in a city where public art has been lying low lately. Not that we don’t have a lot of it—statues along Commonwealth Avenue, mayors behind City Hall. And, you can’t get any better horsemen than George Washington in the Public Garden and Paul Revere on the Prado in the North End.

We’ve endured some retreaded public art. A piano was installed in London, so we installed a piano. Remember the cows, or maybe forget the cows. I saw them in Seattle, then London, Toronto, New York, and finally Boston. It’s not that retread art is bad (except for the cows.) It’s just that better art would be unique and fascinating, with a sense of place.

Cool Globes is retread art in some ways since it has been in other cities. But its purpose is to travel, so we won’t quibble, and besides the globes are fun.

There was a hot phase for public art when the Red Line extension to Alewife was built — if you’ve lived here awhile, you might remember the excitement over the gloves along the escalator at the Porter Square T station.

Most recently, the Greenway has been carrying the torch for public art—a favorite is still Harbor Fog, which puffs out steam as people go by. Some of the Greenway’s efforts were panned as too timid, but its Dewey Square mural, Os Gemeos, installed by the Institute of Contemporary Art, was criticized as too provocative. You can’t win.

In any case, Os Gemeos will be replaced this fall with a piece that may be less controversial. Or maybe not. Perhaps the Greenway’s carousel, due to open at the end of August, will be Boston’s newest type of public art.

Karin Goodfellow, director of the Boston Art Commission, points out that public art has actually not been lying low. It has just been dispersed to many locations. Coming up is a statue of Edgar Allen Poe, complete with raven, on a wide sidewalk at the intersection of Boylston Street and Charles Street South.

Bill Russell’s statue will find a place on City Hall Plaza. The Brighton and Mattapan branch libraries are slated for abstract sculptures. Three pieces of art will go into the new Dudley Municipal Center, which is transforming the old Ferdinand Building and two new buildings into city offices in Roxbury. Design Museum Boston has sponsored “Street Seats,” in which artists installed benches along the Fort Point Channel. Private property owners, such as Liberty Mutual, have also installed sculptural pieces outdoors. There are sculptures enlivening the bleak Christian Science Plaza right now. Temporary exhibits like this one are as welcome as Bill Russell in bronze forever.

Goodfellow said the city has a couple hundred thousand dollars a year from the Browne Fund to pay for public art. That is supplemented by private foundations’ and individuals’ donations. Stephen King was a donor for the Poe statue.

What’s missing is big art. The Bay Bridge between San Francisco and Oakland has been lit with a kinetic display for the past few months. And you’ll probably remember when Christo wrapped Central Park in orange cloth.

Goodfellow said projects like these are expensive. It’s hard to pay for them.

But a little bit of funding is available for something little. The Paintbox project pays artists to decorate utility boxes like the ones that control the city’s traffic lights. Check it out at www.publicartboston.com/content/paintbox‎.

Alston-Brighton is filled with these delights. But historic districts aren’t. One location was proposed in the Back Bay in 2009, said William Young, senior preservation planner in the city’s environment department. The commission denied it. Equipment such as traffic light control boxes are not historic, and the commissioners want to reduce their visual impact, he said.

Unfortunately, the boxes sometimes attract graffiti, heightening their impact.

These ugly boxes themselves need fixing. When a camera, a gps, a calendar, email, the Internet and dozens of apps can fit inside a phone measuring 2 ¼ by 4 ½ inches, there is no excuse for the transportation department to install boxes that block pedestrians and degrade the streets.

It’s time for engineers and industrial designers to transform these necessary but utilitarian objects into something small and beautiful. That would be the best kind of public art.