You’ve probably seen pictures of tree-lined rooftops on skyscrapers and new buildings. But are these green roofs just for show? Or do they have real benefits? This week on Possibly we take a look.

Megan Hall: Welcome to Possibly, where we take on huge problems like the future of our planet and break them down into small questions with unexpected answers. I’m Megan Hall.

Can you imagine going up to the top of your apartment building and enjoying a walk through some trees or doing yoga among some plants? These green roofs are popping up across many American cities. But, what are they exactly? And do they offer more than just some nice greenery?

We had Hamid Torabzadeh and Andrea Li from our Possibly Team look into this question.

Hamid Torabzadeh: Hi, Megan!

Andrea Li: Hello!

Megan Hall: So, what exactly is a green roof?

Hamid Torabzadeh: Basically, wherever we can grow plants such as vegetables, herbs, flowers, and fruits on top of a roof, that’s a green roof.

Andrea Li: There are many different types of green roofs – for example, you could build a vegetable garden or a small park.

Megan Hall: Sounds cool! And how are they actually built?

Hamid Torabzadeh: It can get complicated pretty quickly. But here’s the basic gist: a green roof needs a waterproof membrane, soil, and vegetation.

Megan Hall: A membrane?

Andrea Li: Yeah, the waterproof membrane is basically a layer of material under all the dirt that protects the actual roof from getting wet.

Hamid Torabzadeh: Above it, there’s soil, to help the plants grow and retain just the right amount of moisture.

Andrea Li: And then above this, of course, are all the plants!

Hamid Torabzadeh: To learn more, we went straight to the source and spoke to Mark Winterer, co-founder and owner of Recover Green Roofs.

Andrea Li: Recover is a company focused on the design, installation, and maintenance of green roofs.

Hamid Torabzadeh: Mark says there’s a range of options for green roofs, depending on how much weight your roof can hold.

Mark Winterer: Extensive is the lightweight, shallow system. Intensive is the heavier system that can support trees. And then semi-intensive, I call it the goldilocks. It’s not too heavy, it’s not too light, it’s the sweet spot.

Megan Hall: Got it. And why would we want these green roofs in the first place?

Hamid Torabzadeh: Good question. There are a lot of reasons. These roofs are part of a bigger strategy to make cities more green and livable.

Andrea Li: For one, they can make our cities cooler.

Hamid Torabzadeh: Research shows that green roofs can reduce air temperatures on the roof by up to 20°F.

Andrea Li: They can also potentially save costs by being more energy efficient.

Hamid Torabzadeh: This is because plants can act as natural insulators, reducing the need for AC in the summer and heating in the winter.

Megan Hall: So this could cut down on heating and cooling costs?

Andrea Li:  Yes, but the amount of savings can vary depending on the type of roof.

Hamid Torabzadeh: One study found that a building with a green roof with smaller plants and no trees uses approximately 2 to 17% less energy than the typical roof during summer time.

Andrea Li: But, the building with the green roof was colder in the winter and cost more because the typical roof had better insulation materials.

Megan Hall: Got it. So it can get a little complicated.

Andrea Li: It absolutely can.

Megan Hall: But it seems like there are some serious benefits to these roofs, especially in the summer. Why don’t I see more of them?

Hamid Torabzadeh: The main challenge is the cost of installing a roof- they can be pretty expensive.

Andrea Li: And while these roofs offer benefits, they aren’t necessarily financial.

Hamid Torabzadeh: For example, Boston Medical Center has two rooftop farms installed by Recover on their hospital roofs.

Andrea Li: In 2024, the farms produced almost 10,000 pounds of produce, which they use to feed patients.

Hamid Torabzadeh: But, Mark says, the food Boston Medical Center grows isn’t saving them any money.

Mark Winterer: Profit wasn’t the driver on that one, there is data points on how much yield the rooftop farms are generating. It’s basically equivalent to the cost of what it would cost to to buy the that produce in the first place.

Andrea Li: In other words, green roofs can accomplish plenty of goals- cooling buildings, growing vegetables, and increasing green space. But, saving money usually isn’t one of them.

Megan Hall: Got it! Thanks, Hamid and Andrea!

That’s it for today. You can find more information, or ask a question about the way your choices affect our planet, at askpossibly.org. You can also subscribe to Possibly wherever you get your podcasts or follow us on Instagram, Facebook, LinkedIn, or Bluesky at  “askpossibly”

Possibly is a co-production of Brown University’s Institute for Environment and Society, Brown’s Climate Solutions Initiative, and Ocean State Media.

The post What’s the deal with green roofs? appeared first on TPR: The Public’s Radio.

The post What’s the deal with green roofs? appeared first on Possibly.

If you’ve been outside on a smoggy day, you’ve probably noticed that your body reacts poorly to bad air quality. Maybe you coughed, or got a headache. But what actually happens to your body when you breathe in polluted air?

Megan Hall: Welcome to Possibly, where we take on huge problems like the future of our planet and break them down into small questions with unexpected answers. I’m Megan Hall.

If you’ve been outside on a smoggy day, you’ve probably noticed that your body reacts poorly to bad air quality. Maybe you start coughing, or your head starts hurting. But what’s actually happening to your body as you breathe in that polluted air?

We had Andrea Li and Rachel Chae from our Possibly Team look into this.

Andrea Li: Hi!

Rachel Chae: Hey Megan!

Megan Hall: Before we talk about how air pollution affects our bodies, let’s take a step back. What do we really mean by polluted air?

Andrea Li: So there are six main types of air pollution which can be harmful to public health and the environment. Some you’re probably heard of, like lead and carbon monoxide.

Rachel Chae: But today we’re going to talk about a sort of catch-all air pollutant on the list: particulate matter.

Andrea Li: As the name sort of implies, particulate matter, is not a single type of chemical, but rather pollution made up of a whole host of things floating in the air as tiny particles.

Rachel Chae: If your throat has ever felt scratchy when there’s a wildfire nearby, you’ve probably inhaled these particles. But these particles can also come from lots of other sources. They’re…

Allan Just: released from exhaust from traffic… Emissions from large industrial sources, like coal fire power plants… It’s a mixture that comes from many different sources. 2:51

Rachel Chae: That’s Professor Allan Just. He’s an associate professor of epidemiology and Environment and Society at Brown University.

Megan Hall: Got it. So how does this type of air pollution affect us?

Andrea Li: Even though this air pollution is made up of tiny particles, it actually has a big impact on our health. Because the particles are so tiny, they…

Allan Just: get deep, deep into the lungs and get transmitted into the bloodstream and impact lots of different health endpoints in the human body. It has a long established negative impact on human health.

Andrea Li: For instance, it can worsen conditions like asthma.

Rachel Chae: Yup. It can also cause strokes and heart attacks. For example, high levels of air pollution in Mexico City have been linked to deaths from strokes. But did you know that air pollution can also alter how our brains function?

Allan Just: Our ability to perform work with our brain is negatively affected both by long term exposure to air pollution and even short term.

Rachel Chae: A recent study found that chess players performed better when they were breathing cleaner air.

Andrea Li: Another study found that people did better on standardized tests when they breathed in clean air instead of air with particulate matter.

Megan Hall: Ok. Let me get this straight. When we breathe in air pollutants, they can go into our bloodstream. Once they’re in our blood, they can hurt our heart health and even our brains.

Andrea Li: That’s right.

Megan Hall: Wow. What can we do to protect ourselves?

Rachel Chae: According to Just:

Allan Just: It’s hard for individuals to do as much about emissions, but they can try to avoid adding additional air pollution in their homes, particularly when there’s poor air quality outside.

Andrea Li: For instance, burning candles inside can create particulate matter, although the research is still out about how much of an impact they might have on your health. HEPA air filters are also another way to improve indoor air quality.

Rachel Chae: We can also check weather apps that show the air quality index in our area to stay informed.

Andrea Li: And mask up or stay indoors if those levels are unhealthy. Ultimately, though, it’s up to the government to regulate air pollution from large sources like the coal industry or even wildfires.

Rachel Chae: The good news is— that  it’s very doable to reduce particulate matter. Laws like the Clean Air Act in the US have dramatically improved air quality.

Andrea Li: Plus, cities that are reducing fossil fuel use and opting for clean energy are already seeing big improvements.

Megan Hall: Got it! Thanks, Andrea and Rachel!

That’s it for today. You can find more information, or ask a question about the way your choices affect our planet, at askpossibly.org. You can also subscribe to Possibly wherever you get your podcasts or follow us on Instagram, Facebook, LinkedIn, X, or Bluesky at  “askpossibly”

Possibly is a co-production of Brown University’s Institute for Environment and Society, Brown’s Climate Solutions Initiative, and the Public’s Radio.

The post How does air pollution affect our health? appeared first on TPR: The Public’s Radio.

The post How does air pollution affect our health? appeared first on Possibly.