Creating a Breathable Boston

Linear forests are different from normal trees that dot roads because of their robust root systems and long lifespans. “You dig out a long linear trench and stuff as many trees in there as possible,” Schwartz explains. “You can plant 300 trees in six parking spaces.”
By Akila V. Muthukumar

Martha Schwartz thinks narrower streets could save the world.

“The idea that there’s just not enough room to plant trees is just something we all made up,” said Schwartz, a professor of landscape architecture at the Harvard Graduate School of Design. Schwartz, along with her colleague Edith Katz, recently submitted a proposal to the Harvard Climate Change Solutions Fund to shrink roads and grow more trees. “[The] thesis is that it can bring down the temperature of a city. We have this great opportunity in our streets. There’s a lot of surface area covered that could be recovered in material that allows the Earth to breathe.”

Schwartz believes that Americans don’t value their land enough: They pay attention to what can be built upon that land, rather than how we can best maintain it. Even if trees are not the most profitable or cutting-edge option, “we don’t really have a choice now,” she explains. “We’re not smart enough to be able to reproduce the benefits of natural systems. We have to be very clever in integrating and regenerating these systems through technology.”

While an undergraduate studying fine arts and biology at the University of Michigan, Schwartz was drawn to the “big, beautiful outdoor” scale of landscape architecture .She got her first taste of landscape architecture through Warren Wagner, a botanist and one of Schwartz’s best teachers in college. Working with Wagner, she started thinking about how plants evolve and adapt, as well as how humans can engineer plants.

Four years ago, Schwartz closed her architecture private practice to think about larger issues. “[I] decided that I had to pay attention to climate change,” she explains. “I pretty much put my practice aside and just self-taught. I’ve read lots and lots and lots of books about climate change, and I ended up putting forth a seminar about geoengineering, which I think made everybody think I was absolutely crazy.”

“As I was reading [about climate change science] I found out that the people who are really very active in this are right around the corner from me at the GSD,” she said. “I had a nice friendship with them. I would just go and ask them questions.”

Schwartz began to see how plants, animals, organic matter, and carbon cycles all worked together to keep humans safe.

She realized that we had been conquering nature. It was now time to regenerate it. She incorporated ideas for such regeneration into her designs, which became the beginning of her proposal to the Climate Change Solutions Fund.

“We put so much carbon up into the atmosphere. Now that we have to take down, it turns out that soil and plants are the natural decarbonizing [elements] that we have on the Earth.”

“I actually found a new value for the profession itself,” she continues. Although it felt at times like a niche field with tedious work day to day, Schwartz was spurred on by the realization that a well-designed landscape could define “this kind of next cycle of humanity and humankind.”

One of the ideas within the proposals was to address the urban heat island effect — in which inner cities are ten degrees Fahrenheit hotter than their outlying counterparts, especially when people live in concrete or brick buildings that absorb heat during the day and release it in the night. In places where air conditioning is scarce, Schwartz says, this effect is even more extreme.

Trees might bring relief: They naturally create shade and provide cool habitats while dehumidifying the air.

The proposal took shape in 2017 Schwartz’s studio in the depths of the Graduate School of Design, which she shares with Edith Katz.

Schwartz and Katz set out to integrate a lot more trees into our cities. They worked with Harvard Forest and studied four of the most densely populated townships in the area: Boston, Brookline, Cambridge and Somerville.,

By 2060, they reasoned, cars will be smaller — much smaller. This means city streets could be narrower, reimagined to make room for more trees.

Katz and Schwartz’s team determined we could shave 20 to 25 percent off of all the streets and plant linear forests with the new space. Linear forests are different from normal trees that dot roads because of their robust root systems and long lifespans.

“You dig out a long linear trench and stuff as many trees in there as possible,” Schwartz explains. “You can plant 300 trees in six parking spaces.”

Of course, a research proposal only exists in the ether: How will these 300 trees actually be planted? To answer this question the team turned to Shubhendu Sharma, founder of Afforestt, an organization that plants trees native to particular regions to plan for the practical methods.

Once planted, how would the trees be watered? Natural aquifers take thousands of years to regenerate and drilling for water is a temporary solution. Realizing that it takes a village to create a landscape, the team turned to another collaborator :Rob Adams, a city planner in Melbourne helped them understand how to water these trees once planted.

His method involves adding devices in tree trenches to capture water that would normally run off the sidewalk and into a sewer. This means older cities like Boston will actually be less prone to disease since their sewer systems are no longer attached to stormwater drains.

Schwartz knows progress will be gradual — at times, painfully so. She anticipates years of advocacy and outreach to convince people to narrow their streets. In the end, however, she hopes to afforest as much of the city as possible.