AYESHA RASCOE, HOST:
The heaviest rainfall in more than a century this past week has spurred South Korea to take massive steps to make the country more prepared for the impacts of climate change. The city of Seoul announced it will spend more than a billion dollars to build massive underground holding tanks to prevent flooding. And it also vowed to prohibit people from living in basement apartments, like the one where one family drowned. The flooding is just one example of how cities around the world will be affected by climate change. Joining us now to explore how is Eric Chu, an assistant professor at the University of California, Davis. He does a lot of work on climate change and urban planning. Thank you for joining us.
ERIC CHU: It's good to be here. Thanks for having me.
RASCOE: The South Korean president said the heavy rainfall was, quote, "believed to be due to climate change." Can you link this heavy rainfall directly to climate change?
CHU: It is possible, although linking one specific event to this specific place to a complex kind of global challenge like climate change is quite difficult. However, the main message here is the events that we saw - the unfortunate events that we saw in South Korea are part of a longer trend of increasingly extreme, erratic weather climate events that we have observed and seen across the world.
RASCOE: The images out of Seoul - they were so dramatic. You had the man on top of his car in the middle of this flooded intersection. Reuters is reporting that at least 11 people died. Are these the sorts of dangers that cities face if they don't act quickly enough to address changing climate and the way climate change is affecting these cities?
CHU: Yes, the losses, both financial and human, will inevitably increase because the capacity of our infrastructure and our communities and our economies to adjust and adapt to increasingly variable and extreme climate events - that capacity will decrease.
RASCOE: And so in response, you have Seoul now looking at banning basement apartments. What other cities and regions have started to take steps against climate change? Like, what can you do for things like flooding but then, I guess, also for things like heat?
CHU: A lot of cities are making some progress on dealing with floods. One of the main issues with heavy downpours is that the way that we've built cities - full of concrete and surfaces that are not permeable with only very specific but few drainage entry points. When you get a downpour, all the water sort of rushes down into this one drain. And when that one drain is blocked, then the entire street, the entire neighborhood is flooded.
RASCOE: Yes, I know about this personally, yes, in my neighborhood (laughter).
CHU: Yeah, so one way of doing that is if you have porous pavements, streetscapes, parks that allow for drainage of water, seepage of water through it, that sort of relieves the drainage system from when those heavy downpours are happening. So that's one. Some cities are retrofitting their wastewater pipelines - going in and building in water storage tanks and cisterns across the city so that the water has somewhere to go.
RASCOE: What about when it comes to, like, extreme heat, which we've seen throughout the U.S. this summer?
CHU: Yeah, I live in California. This is our normal. We do this every summer. It's getting worse. We have new building technologies around passive cooling and ventilation. So rather than sort of block, block, block buildings, you have central courtyards, or you have different ventilation spaces throughout the building with windows and kind of build different architecture techniques, so that naturally ventilates the building because the last thing you want to do is to put in more air conditioning units because that sort of defeats the purpose.
RASCOE: That's what I was thinking because I'm, like, it seems like to deal with heat, you need AC, but that seems like that would lead to more carbon emissions.
CHU: Absolutely, absolutely.
RASCOE: OK.
CHU: There are circumstances where more air conditioning is needed, especially for maybe vulnerable neighborhoods that take time to retrofit buildings. Yeah, they can do quick things like put in reflective paints on their roofs or on their walls so that that helps reflect some of the sunlight and the heat from the buildings themselves. But retrofitting buildings takes time, and it's expensive. And historically disadvantaged communities, poorer neighborhoods in cities don't have the kind of ventilation, don't have the green space to allow for that kind of natural ventilation that can happen.
RASCOE: Eric Chu is an assistant professor at the University of California, Davis. Thank you so much for speaking with us.
CHU: Thanks for having me. Transcript provided by NPR, Copyright NPR.