How can cities adapt to rising heat? Green design architects can help

RACHEL MARTIN, HOST:

The London Fire Brigade had its busiest day since World War II on Tuesday. The fires they have been fighting, more than 2,600 of them, began because of the record-shattering heat wave happening. Brigitte Clements is an architect specializing in green design. She's been helping cities adapt to climate change. But when I reached her in London, she said even she has been surprised by the heat.

BRIGITTE CLEMENTS: We're quite awestruck, I think. Luton Airport runway has melted. You know, flights had to be diverted. Also, the train lines to the airport were canceled. There's been fires across the capital and surrounding counties. You know, houses have been burning down. The London Underground was very, very hot yesterday. It got up to 36 degrees - I think that's about 96 degrees Fahrenheit - inside the subway cars. So the streets were quieter.

MARTIN: Well, let's talk about some of the design and construction solutions. Other parts of the world see temperatures this high regularly. How do they keep their airport runways from melting and their trains running?

CLEMENTS: I mean, it's not just about the materials. I mean, there's two things that we need to do when we're looking at extreme heat. One of them is reducing thermal absorption, the rate which we get hot. The second is, you know, how to integrate natural cooling strategies, right? That's a more holistic approach. So you need a kind of two-pronged approach to this.

MARTIN: What are those? I mean, barring putting new air conditioners into every building, which is not environmentally friendly, what are the cooling alternatives?

CLEMENTS: There are natural processes that are already in play and that have been used for a long time in a design sense. I mean, in a very simple way, you know, just cross-ventilation, making sure that there is wind movement through buildings and bringing cool air, having reflective roofs. Black absorbs more than white. If you go to Greece, you know, a lot of the roofs are white. That is a very, very simple intervention. I mean, in parts of Australia, they've just banned dark roofs completely. But I think the biggest one's evaporative cooling. This is when plants transpire. So like you and me, they sweat. And the process of evaporation has a cooling effect. So having a lot of greenery, you know, greening up the cities...

MARTIN: Green roofs.

CLEMENTS: Yeah. Well, green roofs is a very big one. I think this, for me, is probably one of the most obvious solutions. In Basel - this is in Switzerland - green roofs make up about 40% of the roofs' surfaces. This is a result of an initiative started about 20 years ago. They basically asked the residents, what would you think about having a 5% levy on our energy bills to help subsidize green roofs in Basel for all new builds and retrofit of flat roofs? Green roofs have, in summers, a benefit of reducing indoor temperatures by up to five degrees centigrade. And so this is free.

So if you, you know, asked anybody in London right now, you know, how would you feel about reducing your indoor temperature by five degrees, especially with these spiraling energy costs, I mean, everybody would be quite happy about it.

MARTIN: What are some of the biggest challenges in the U.K. to making that happen?

CLEMENTS: I think getting people to take it seriously.

MARTIN: Still?

CLEMENTS: Still. I think the penny is starting to drop. You have to realize that this heat event is our first at this level. So I think we need to get, you know, more cultural transformation and a shift in mindset. But ultimately, we can't rely on the goodwill of people; we need the government to have a strong leadership and create policy and legislation to help guide us through this and with very, very clear and quantifiable goals and targets.

MARTIN: Brigitte Clements is an architect in London focusing on sustainable design. Thank you so much for talking with us.

CLEMENTS: My pleasure. Transcript provided by NPR, Copyright NPR.