In the Attica region of Greece this August, says Bas Smets, wildfires ripped through forests left parched by record-hot temperatures, with heat waves starting June 12, earlier than ever before.
“They had to close the Acropolis,” he said, “which is the most visited tourist attraction in Athens.”
By the end of the summer, the fires had claimed one person’s life and left more than 150 acres scorched. The ongoing drought, following Greece’s hottest summer on record, forced residents to surrender tourism income when they couldn’t supply water for their guests. And, this fall, chestnut and olive farmers yielded diminished harvests. Experts warn that Greece’s water crisis will be ongoing.
Smets, professor in practice of landscape architecture at the GSD, is at work alongside his students in Athens this semester, developing an intervention as part of his multi-course series on biospheric urbanism, which involves carefully measuring each city’s climate and infrastructure, mapping the climate for the next hundred years, and then “hacking” into the system to create what he calls microclimates, which aid in human and nonhuman survival and, ultimately, mitigate climate change. “Biospheric Urbanism is the study of the built environment as the interface between meteorology and geology,” Smets writes in an introduction to the studio. “It seeks to transform the critical zone between the above and the below, to better adapt to uncertain changes in climate while optimizing the use of underground capacities.” So far, Smets’s courses at the GSD have focused on New York and Paris, operating in tandem with his firm’s projects at Notre-Dame in Paris, Luma Park in Arles, and the Scheldt River park in Antwerp.
As climate change wreaks havoc around the world, says Smets, he believes the solution requires systemic thinking and wide-scale collaboration. Noting common factors in the recent floods in Valencia, Spain, as well as other similar catastrophes in Europe over the past few years, he pointed to how, “the construction of the city restricts the river. So, when we make a design proposals, of course we make it for a specific site and context. But, we are also thinking of it as a systemic concern. How can it be designed in different variations that then could be taken up by other designers, in other cities?”
Building on the work he undertakes at Bureau Bas Smets, he is creating with his students a catalogue of at least 60 scalable hacks that could be adapted worldwide, creating an endless series of urban microclimates that both improve habitability and help fight global warming. “The problem is so big today that the only way out is a collaborative effort,” Smets said. “It’s not about who has the best idea. It’s about, How can we have as many good ideas as possible together? I really believe in that. That’s why I started teaching at Harvard, to share ideas.”
This fall, Smets presented his work in “Changing Climates,” an exhibition and related talk at the GSD that illuminated how deeply he involves his students in his urban biospheres projects. The sense of collaboration that he cultivates in his studio over the course of the semester was evident in the students’ final presentations, as they described how their Athens designs might work in tandem, and how those ideas could be adapted in any city.
A New Kind of Cartography
Smets’s studios depart from the traditional studio format by beginning not with a designated site, but with exploring a city. He wants his students to think critically, finding their own hacks within the urban landscape. The first phase in every project is to create a map, examining, “all the elements of the microclimate, from heat islands to wind speed, humidity, soil, trees, and canopy cover. We try to make a new map of the city by taking into account all the microclimatic elements.” In addition to taking meteorological measurements from across the city, students gather GIS data, study topological and historic maps, look at underground systems like subways and old plumbing infrastructure, as well as parks, building height, and even construction sites.
“I care about cartography, like Alexander von Humboldt and explorers who made their own maps of reality. I want students to make a new map of reality,” Smets said of his approach. “I don’t give them a site, but I ask them to find the site that has a problem. I’m trying to create critical minds that don’t respond to a question, but that ask the question themselves.”
For example, when studying Manhattan in Spring 2023, student Jiyoung Baek (MLA I ’23) found that scaffolding on building facades covers an area equivalent to one third of Central Park. Baek discovered that building owners relied on a loophole to save money: It was cheaper to keep up unsightly scaffolding and pay the city’s fine for failing to remove it, than to pay the cost of removing it and reinstalling it every ten years for required maintenance. Baek proposed transforming each of the scaffolds into green spaces—improving both the aesthetic and environmental quality of the city.
Another student, Parama Suteja (MArch I ’24), looked at the original topography of Mannahatta, as it’s called by the Lenape nation, before it was leveled and developed. Suteja proposed reintegrating the island’s original hills by planting gardens on rooftops and other abandoned spaces. In Paris in the Fall of 2023, Crane Sarris (MLA I ’24) proposed using old underground car parking lots as refuges in the +5 degree future, creating a multilayered underground park, “Musée du Parc,” inspired by the 1867 Paris Exposition. And, Leila Breen (MLA I ’24) hacked one of the abandoned underground quarries in Paris, Bergerye Soutterrain, to create “climate-proof underground spaces along lines 2 and 6 of the Paris Metro,” including space for dancing, reading, swimming, and mushroom agriculture.
Smets argues that, by looking at the city and finding their own interventions, students develop themes that can be applied in other urban landscapes. “They make a project not only for their site, as we traditionally would do, but for the theme that is applied to their site. That way, it becomes systemic.”
Using Succession to Create Microclimates
Once students have found their intervention, Smets asks them to do a close analysis of the site, considering how it will look far into the future as climate change takes hold. “We work with four scenarios: 2 degrees more, in 2025; 3 degrees more, in 2050; 4 degrees more, in 2075; and 5 degrees more, in 2100. That also allows to have a range of proposals that get more and more drastic. It works well to see the gravity of the problem in stages, as well as the necessity of solutions that become more adapted.”
Rather than planning merely for survival in each time period, Smets’ landscapes are made to predict and help advance succession, the natural progression that forests undergo as they develop from open spaces to mature canopies. “How can we accelerate that process?” Smets asked. “How can we use the force of nature to have it come back to the city?”
He applies natural conditions found in the “wild” to atmospheres created in urban landscapes, implementing, for example, water retention systems and forests that would take hundreds of years to grow, to create cooling systems that allow people to enjoy the city while promoting climate resilience. In considering the wind, Smets studies how it would bring sediments, trees, shrubs, and ground cover to the site. As the force of succession proceeds, the slope of the earth and therefore wind patterns would change, and the vegetation would change. For each subsequent succession, the design is pushed further into the future. Three hundred years later, there’s a new ecology. This speculative design process is done in collaboration with pedologists, hydrologists, and ecologists, as well as with climate engineers from Transsolar, which continues to track conditions at the site after the design process, above and below ground.
At Luma Parc des Ateliers in Arles, Smets was presented with a flat, industrial wasteland, and planned a landscape that included 80,000 trees and shrubs, which they planted one by one. In the years after, one hundred of those trees are continuously monitored, as the team returns to the site for visits, helping the site to develop. One species might be found to thrive where another falters, and the team can swap them out. At the team’s Arles site this summer, the perceived temperature was lowered by 20 degrees, in large part due to evapotranspiration—the water trees emit from their leaves during photosynthesis—and the evaporation from the lake the team created. This, says Smets, is proof positive that microclimates can be created in urban landscapes.
Striking Water in Athens
In Athens this summer, temperatures soared 1.6 degrees above normal. “Two degrees,” said Johnny Zhong (MLA I AP ’25), “is the warning before the dominoes begin to fall.”
The immediate solution, he suggested, begins with a sustainable tree canopy, which provides shade as well as the cooling effects of evapotranspiration. Citing a checkerboard of abandoned lots across the city with neoclassical facades that he’d maintain, Zhong illustrated how he could increase the city’s public tree canopy by 138,673 square meters, with underground water aquifers to collect rainfall for the trees.
Thinking at the level of the neighborhood, Carlo Raimondo (MLA I ’25) turned to Greece’s “stoa typology” to transform urban pathways into vine-covered shaded walkways, bougainvillea blooming over formerly scorching sidewalks. Because certain crawling plants, such as Roman hops and wine grapes, flourish in drought conditions that would kill a tree, Raimondo imagined using bollards, installed to protect pedestrians on the sidewalk, to create stoas. This makes Athenian’s existing pathways more useable, and creates new, shaded paths around the city.
Moving further into the climate crisis, to +3 degrees, Muyao Zhou (MLA II ’25) proposed a toolkit—adaptable to any urban context—for collecting rainwater from city roofs and growing rooftop forests, because, as one of the critics noted, “water is the new gold.” Meanwhile, Sitong Wang (MLA I AP ’25) created a citywide shaded walking loop, and Hayden Bernhardt (MLA I ’25) looked below ground, finding limestone pockets underneath abandoned lots. Capitalizing on limestone’s permeability rate of 25-30 percent, he transformed the deposits into wells whose ground-level pools are equipped with misters to cool the area and help vegetation flourish. He noted that the wells could be filled with rainwater collected by Zhou’s rooftops.
The possibilities for inter-reliance among the projects seemed endless, and, Smets emphasized that these projects represent not 11 distinct ideas but a collective intelligence. “Students help each other. We create a community,” he said.
Ultimately, Smets’ concept of urban biospheres, “transforming the critical zone between the above and below to better adapt to uncertain changes in climate,” is grounded in hope. He explained that, working in Athens, a city that’s full of reminders of thousands of years of human history, “it’s interesting to think of the past and the future.”
Smets has an optimistic view of what’s possible, noting that as we move through the effects of climate change, the interventions we make now could be altered later: “The unexplored archeology sites in Athens are amazing opportunities to make carbon sinks. What if we put an anti-root layer to protect those sites, add soil, plant a mini forest for the coming 200 years.” Then, once we’ve survived this phase of warming, people might harvest those trees and excavate the sites to learn about how we lived two thousand years ago. “Maybe the urgency now is to make the planet livable. It’s a whole different way of looking at both the past and the future.”