Heat mapping: adult science project can be fun too!

I didn’t get a ton of science projects as a kid, but no matter, I learned recently that there is such a thing as a fun adult science project! I volunteered as a “citizen scientist” this summer for the Museum of Science, and boy, did I have a grand time.

I heard about this opportunity through Greenovate Boston – a citywide initiative to empower residents to carry out community level actions in support of Boston’s climate goals (think urban wild cleanups, weighing in on climate resilience plans, etc). The project I volunteered for is called urban heat island mapping.

Hot girl summer, on repeat

If you haven’t heard of the concept of “urban heat island”, the gist is that a metropolitan area is often significantly warmer than its surrounding rural areas due to human activities. There are many causes of the urban heat island effect: burning fossil fuels for transportation, air-conditioning that sends out hot air, building/road materials like asphalt and concrete that absorb heat from the sun during the day and release the heat at night. This means cities don’t get as much of a chance to cool down at night, compared to surrounding non-urban areas.

An illustration of the urban heat island effect. Image credit: World Atlas.

Why does this matter? For one, our cities are getting hot, fast. You have probably heard that Europe shattered its temperature record this summer, with Paris hitting an all-time high of 109 degrees. This is true even in New England, where summers tended to be cool and heat waves used to be rare.

According to the Museum of Science, the average summer temperature in Boston from 1981 to 2010 was 69°F, but might reach 76°F in 2050 and 84°F in 2100 (note the word average!!!) Same goes for heat waves, see graph below. Now imagine what it’ll feel like to live in Alabama if it’s 90°F every day in Boston!

A map of land surface temperature showing how much hotter metropolitan Boston is compared to surrounding areas (image credit: MAPC). The right bar shows the estimated days above 90°F in Boston (I copied this image from the slides the Museum of Science created, but I’m not sure who to credit here. Sorry!)

Extreme heat is not only deadly for humans and animals, it is crushing to our already under-invested infrastructure, such as power grids, roads, and waterlines. More importantly, the impact of extreme heat isn’t distributed evenly across the population; seniors, kids, people with outdoor jobs, the chronically ill, and low income people (e.g., lacking access to ACs) are especially vulnerable.

The first step in mitigating the urban heat island effect is better data, because the impact of human activities on city temperatures is hyper-local (by hyper, I mean block-by-block hyper). This is where the urban heat island mapping project came in.

“Wicked Hot Boston”

As a “citizen scientist” I was part of a 50-person volunteer group that collected ambient air temperature data in various neighborhoods of the greater Boston area. Volunteers drove or biked on pre-planned routes with sensors that recorded such data at different times of the day, during 3 heat waves in late July and early August. The end goal was maps that show how heat fluctuates in certain parts of the city throughout the day – data that will be valuable for city planners and public health officials.

For my 6am “shift” on July 29 I was paired up with Peggy (who was a retired nurse practitioner specializing in HIV care, garden designer, and local climate activist, aka basically who I want to be when I grow up <3). We attached the sensor to Peggy’s car, and my task was to navigate us (on pre-planned routes selected by city planners) while Peggy focused on driving under 35 mph. (This is important because driving at high speed will lead to wind that starts to cool the air around the sensor so the data won’t be as accurate. And if you are familiar with Boston’s aggressive driving culture, you can imagine staying under 35mph is no easy job!)

This task was repeated by volunteers in 10 neighborhoods in Boston, Brookline and Cambridge. The data were then used in combination with satellite data to create maps that show the absolute and real-feel temperatures across the city.

The results? Maps that show temperature differences as high as 15°F in the same city, depending on where you are! Wow, wow, wow. It’s one thing to learn about something in the abstract; it’s totally another to feel it and see it in your own city. Unsurprisingly, the denser an area is and the less green space it has, the hotter it tends to be. The researcher in me is dying to see this map layered with some neighborhood-level income data, as the correlation between higher heat and lower income is well-documented.

Boston isn’t the only city that has engaged residents in such fun and meaningful work. Seven other cities were selected and funded by the National Oceanic and Atmospheric Administration this summer for similar campaigns, and I can’t wait to check out their work.

What’s next?

With better data on where and who to target, what we need now are thoughtful policies, programs and individual actions that will mitigate the urban heat island effect. This could include actions to ensure safety during heat waves (such as increasing access to ACs), funding to protect infrastructure, or more preventative policies to cool the city (tree-planting, installing green roofs or reflective surfaces). While I know a couple of maps won’t get us there, I’m incredibly proud to be a part of a project that’s helped to raise the issue of extreme heat in the press. Dealing with climate change can feel so existentially daunting as an individual, and I can’t tell you how refreshing and empowering this experience has been for me.

What can you do? Even if your city isn’t one of the eight participating in heat mapping, I’ve still got a long list of action items for you:

  • Use extreme heat as an example to engage in conversations with others about climate change, because this is something most people have tangible experiences with.
  • Educate yourself about the urban heat island effect, and contact your local representatives about the importance of putting resilience strategies in place.
  • Find a citizens science project that you (and your kids) can contribute to!
  • If you live in the Greater Boston area, sign up for the Greenovate newsletter already!