Spotlight: Suzy Li, Graduate Smart Surfaces Scholar
This interview is part of a series of blog posts highlighting prominent members of our Smart Surfaces team. Over the coming months, we will publish interviews with Coalition members as they talk about their work, our environment and the Smart Surfaces mission.
Suzy Li, LEED AP, received her Bachelors in Urban Planning at Beijing University of Technology, and her Master of Urban Design and Master Science of Architecture in 2013 and 2014 at Carnegie Mellon University (CMU). She is an adjunct instructor at CMU, co-instructing the course Urban Design Methods. An urban design professional in the Urban Planning and Design Academy of Beijing University of Technology from 2016-2018, Suzy has returned to pursue her Ph.D. in Building Performance & Diagnostics at Carnegie Mellon University. She has worked with the USGBC Orange County Market Leadership Advisory board, advising on strategic and tactical activities to expand the green building marketplace for the USGBC. Smart Surfaces is the focus of her thesis — developing a smart surface taxonomy and finding quantified benefits for the environment and quality of life.
As part of her work with the Coalition, Li created a five-minute animated video that illustrates the transformative power of implementing smart surfaces. View the video, and read about her Smart Surfaces research.
PL: What unique angle or perspective do you think the Smart Surfaces Coalition brings to like the issue of climate change?
SL: In academia, there's a research gap, missing a comprehensive understanding of smart surface impacts on heat, water and carbon. How do we call the attention of the policymakers and the decision-makers to think all about all of the different impacts at the same time? Because different cities have different problems. Some have heat problems, and some have flooding problems. If you talk about a flooding problem, it’s harder for drier cities to recognize the importance of that problem. And if you're talking about an urban heat island effect [where cities are, on average, 9 degrees warmer than the surrounding countryside], some colder cities won’t care. The power of the coalition is to bring the silos together, bring the separation together as a unified result. It's everybody. It's amazing. That power is amazing.
PL: Can you talk to me about your first-ever encounter with the idea of climate change?
SL: When I started my Ph.D. in 2018, I was trying to [define] the direction of my research at the time and encountered the idea of an urban heat island. Before that, I was an urban designer. What I did was focus more on the quality of the space, the aesthetic, the flow of people and transportation. I wasn’t paying a lot of attention to the climate part at that time, but climactic urban design has become a big part of my interest right now, [thinking about] how to integrate the climate impact of design into the process. It’s an urban design theory that needs more attention in the education program right now, especially with the current rate of climate change.
PL: Can you talk about how your research is connected with smart surfaces?
SL: Starting this [Ph.D.] program, I was focusing on building energy efficiency. In a lot of my coursework, professors spoke about the impact of increased building energy consumption, which leads to an increase in the peak electricity demand. And when the power plant generates more electricity, it has a consequence of increased carbon emissions, which would lead to climate change. So it’s a very big topic that was missing from my experience in urban design.
But especially [through] studying with [Coalition Steering Committee chair] Vivian Loftness, I know there is the difficulty of having people paying attention [to the issue] or investors willing to invest in strategies to mitigate the climate change or urban heat island issues — because developers or city decision-makers would most likely pay attention to the first [up-front] cost or the financial impact of a project, rather than paying attention to long-term impacts and the impact on the society or the environment. All of this is sort of leading me, guiding me to identify the benefits of smart surfaces in all three bottom lines: financial benefits, the climate environmental benefits and human benefits.
Part of my thesis was to collect data and do a mapping and statistical analysis on how smart surfaces are really impacting quality of life, energy use and climate change. It's a combined effort of all three bottom lines. So then, it's easier or more likely to convince city decision-makers to say, “Hey, when you only look at the up-front cost, what kind of choice would you make on the city surfaces? And if you are also showing the second and the third bottom line, the environmental and the human benefits to your city, is your decision going to change?”
I think that shares the same goal with the Smart Surfaces Coalition, right? That's the focus of my thesis.
PL: How did you get involved with the Coalition?
SL: Vivian Loftness is my advisor, and it has been a great opportunity for me to work with her on the development of the smart surface taxonomy. We realized there was an absence of the typologies of all city surfaces right now, and if want to do a study, that's more comprehensive, that includes heat, water and carbon, and all types of urban surfaces, we have to figure out, how many types of surfaces are there, and what are their quantified benefits?
Because my Ph.D. thesis is on smart surfaces impacts on climate change, human health and social equity, joining the coalition was a natural step. According to Greg Kats, I am the first Ph.D. candidate who is studying the impacts of smart surfaces. I am very honored to be the first, and I think it’s a very valuable topic for more attention to fight against climate change.
PL: Can you say a little bit more about the process you went through to quantify smart surface benefits?
SL: So, first of all, for the taxonomy, what I did was, given the three types of surfaces — parking lots, roofs, streets and sidewalks — I brainstormed all the different possibilities for each type and called it a surface component library. There are different perviousness levels and different colors — which indicates the albedo level — as well as different levels of greenness. Greenness coverage is a separate metric for smart surfaces because albedo cannot accurately capture trees’ cooling capacity.
For each type, you can have these three different metrics in different combinations. And for water management, you can also have the potential to have water storage underneath. For greenness, [a surface] can either have just trees, or trees combined with bioswales. There’s also PV, which is only for roofs and parking lots for now.
PL: Where are you now with your research?
SL: I’m working on identifying what are the outcome benefits and potential benefits from each of these metrics? For example, what is the effect of albedo on surface temperature and CO2 reduction capability, or the impact of permeability and rainwater retention rate on stormwater management? [Smart surfaces] can reduce the surface temperature, carbon emissions and also increase the ability to absorb more rainwater.
The three ways of measuring outcome benefits of smart surfaces are surface temperatures, rainfall retention per event and carbon benefits, translated to cars driven avoided per year. These three measurements were chosen because of public awareness, and because they are easy to understand. Jargon — like albedo or curve number — is hard for the general public to process. This is also part of the contribution of this thesis, to overcome the technical barriers for decision-making.
Through a systematic literature review, I was able to identify the comparable values for each type of surface. To quantify surface temperature, I identified values for reflectivity for each surface type, and then identified the surface temperature benefits from field study or experiments. To quantify stormwater benefits, I used a curve number and runoff calculation equation, found out to maintain the runoff amount as zero and calculated the maximum rainwater retention capacity per event. To quantify the benefits of carbon, I developed three different paths: albedo-related carbon savings due to avoided energy consumption and negative radiative forcing when albedo increases; greenness-related carbon benefits due to avoided energy consumption and carbon sequestration; PV-related carbon benefits due to avoided electricity CO2 emissions from power plants. It was a very long process, but it fills a very significant gap in the research field.
There are a lot of people focusing on these city surfaces and their impact on climate change, but they are scattered and siloed — they either just focus on heat, or just focus on the rainwater, and so on. My job is to bring all these together so the decision-makers can see them all at once.
PL: What else is next for your research on smart surfaces?
SL: I have the taxonomy with the different types of surfaces, so the next step would be to see how to classify this larger, more specific set of surfaces using image processing, on a larger scale, say, for a city. I want to see if it's able to classify surfaces based on the taxonomy that I developed so that I can do further statistical analysis to get the correlations between the smarter surface texts on coverage and the different outcome benefits such as air quality, urban heat islands, flooding, etc.
PL: If cities were to make one or two widespread changes, which ones do you think would be the most effective and why?
SL: Of the three categories, roofs, parking lots and streets, I would say parking lots, because they cover such a large percentage of city land area. It has so much potential to change the current situation, compared to the streets and sidewalks, because parking is such a blanks surface right now. And it's over-designed because of the zoning code that requires parking lots to have a maximum capacity for Thanksgiving, for Black Friday, those days. But most of the time very little of the space is actually used, and it just stands there as the dark black impervious surface and which will generate a lot of runoff and impact on the surrounding neighborhoods. So if, if developers and the cities can start to change these regulations or incentivize the change in the parking lots by introducing more green surfaces, like trees and bioswales, it will reduce a lot of the flooding risk as for the surrounding neighborhoods. Parking lots also have the potential of having PV as a shelter. You can integrate all kinds of smart surface solutions into this.
PL: What are the top two pieces of advice you’d give to someone thinking about implementing smart surfaces?
SL: I think the [cost-benefits] analytic engine is a very powerful tool to show that if you invest in smart surfaces, you have an extraordinary amount of financial benefits. It’s a powerful tool to change their mind.
The other thing is that it’s very necessary to start from community engagement. You have to start with public education in the community, in the neighborhoods — to let them know and be aware that not having smart surfaces is negatively impacting their quality of life, and in their neighborhood.