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Can cities help us fight climate change?

19 minutes 28 seconds

Speaker 1

00:00:00 - 00:00:32

This is The Guardian. If you're a regular Science Weekly listener, you'll know that the outlook for the planet right now is a bit... Bleak. But the climate crisis also gives us an opportunity to reimagine how we live for the better. So we're asking what do we want the future to look like?

Speaker 1

00:00:34 - 00:01:16

Whether it's our diets, our homes, our families, what should lie ahead for humanity? Today we think of them as smoggy concrete jungles. But how could our cities help us create a climate-friendly future? Heatwaves like those currently sweeping India, China, Thailand and even Spain are even more punishing and deadly in cities, as human-made hard, dry surfaces absorb and trap the heat. And on the flip side, that also makes them more prone to flooding when the rain finally arrives.

Speaker 1

00:01:17 - 00:02:05

So forget smart cities, giant shiny skyscrapers, huge screens flashing with adverts, robots flying above us. The future of cities is wilder and greener than you think. From The Guardian, I'm Madeline Finlay and this is Science Weekly. To form an idea of what the alternative future city might be like, I headed to Colchester in the east of England to meet Ben Wilson, historian and author of Urban Jungle, a book about the relationship between nature and cities. Colchester was a fortuitous place to meet.

Speaker 1

00:02:05 - 00:02:30

It's often called Britain's first city, becoming a Roman capital in 49 AD. Then, after a rather long hiatus, last year its city status was returned. So now it's our newest too. As we stood on the River Cole, with some blocks of flats on 1 side and a disused area of weeds and reeds on the other, I asked Ben how he envisaged a future city.

Speaker 2

00:02:30 - 00:03:12

The city of the future, if we're protecting ourselves, if we're serious about protecting biodiversity, is developing cities that are a bit more in tune with nature, that can acknowledge the fact that cities are destructive forces, but cities are adaptable things. They change and meld as very complex systems. The way they're dealing with complexity now and the way they're evolving now is that they are taking some account of nature. That is happening in city after city around the world. Now, I would expect in the future that we will see cities where that dividing line that we've kind of built up to divide city from nature, that barrier will break down and there's a bit more of a mash-up of those kind of things.

Speaker 1

00:03:13 - 00:03:33

And there is plenty of opportunity, if we're willing to let go of the idea of neat, orderly nature in allotted areas like parks and instead welcome in a bit of messiness, rewilding them with local, hardier plants that can take care of themselves and even revive ecosystems.

Speaker 2

00:03:33 - 00:04:14

Cities in a way can be a refuge because they have lots of these marginal, leftover edge spaces. The things between uses are really important because that's where nature can really insinuate itself into the landscape. The Dutch have a really good thing where they leave building sites for longer because there's a huge amount of uptake of pioneer plants on building sites. It could be really good locally for nature before it's built upon and it can look wonderful but you can only really appreciate it I think if you take your mind away from sort of seeing wanting to see tidiness in the city and you want to see biodiversity, really, really well reflected in this classic kind of post-industrial landscape in Colchester, which is very typical and sort of shows the urban ecosystem at its best because it's unexpected.

Speaker 1

00:04:17 - 00:04:32

A study from the conservation charity Zoological Society of London found that restoring biodiversity in urban environments could boost wildlife and help protect city residents from forest fires, heatwaves and flooding.

Speaker 2

00:04:33 - 00:04:40

Roads here in London were flooded on Sunday as thunderstorms and heavy rains battered the British capital.

Speaker 1

00:04:40 - 00:04:47

Every year around the world, we're increasingly seeing our cities getting hit by dangerous and damaging floods.

Speaker 2

00:04:47 - 00:04:52

July last year, we saw flash flooding in London. 2 months worth of rain fell in 2 hours.

Speaker 3

00:04:52 - 00:04:56

Parts of Sydney have received about 8 months of rain in 4 days.

Speaker 1

00:04:56 - 00:05:19

A once-in-a-century weather event has now happened twice just this year. And scientists at the non-profit organisation Climate Central... ...Estimate that 275 million people worldwide... ...Live in areas that will eventually be flooded... ...At 3 degrees Celsius of global warming But it's a problem that Ben said we needed to start working on now.

Speaker 2

00:05:20 - 00:05:56

A lot of the modern cities aren't designed to cope with the amount of water that is already falling on them and will likely fall on them. And the sea level rises that we're going to undoubtedly going to experience and will be the biggest danger to urbanization in the 21st century and going forward. The only solution really is what a lot of cities are doing, which is to mimic the natural hydrology of what was there before. To treat water not as something you need to get rid of really quickly, but something the water's got to go somewhere, it's got to be contained somewhere and released back into the environment in a clean and filtered way rather than the filth and dirt that comes with flooding. So how do you do that?

Speaker 2

00:05:56 - 00:06:44

1 city I'd look at is Copenhagen that had an enormous downpour in 2011. Rather than wait for the next rainfall to come along and not do anything about it, they were proactively looked at re-engineering conventional parks, play parks, recreational parks, re-landscape them so they were more undulating so when the rain does come they can flood as temporary wetlands and water parks, turn streets into temporary rivers and streams, similarly with underground car parking spaces that can be flooded, but also change the, go back to what Copenhagen was before it was built on, to bring back that hydrology of where does water want to go. So that's using green infrastructure really, taking out the hard carapace and replacing it with things that can soak up water makes a huge amount of difference.

Speaker 1

00:06:45 - 00:06:49

1 piece of natural technology can protect us and our cities. Trees.

Speaker 2

00:06:50 - 00:07:13

So trees provide this amazing air conditioning for cities. As they're warming up we see their value and we see, you know, the trees actually have an economic value. It's a horrible way of looking at a tree. It's called treeconomics, of course, because of the services they provide in terms of cooling, also soaking up rainwater. So we can't really have enough trees in cities in a way.

Speaker 2

00:07:13 - 00:07:40

There's this enormous, sprawling, thick, tangled, swampy forest right in the middle of Dallas, Texas. Not something you associate with Dallas, but because it's been neglected, it has this incredible kind of ecosystem. It's a real sort of jewel in the crown of a city like Dallas. Madrid is planting a big sort of circling, protecting ring of forests, so is Beijing, because cities really need that. They're the sort of city walls of the modern age.

Speaker 2

00:07:40 - 00:07:47

And the value that trees bring to the wider ecosystem is in their understory, what they do to the soil, fungi, you know, things like that.

Speaker 1

00:07:48 - 00:08:00

Why is good soil so important? As the climate changes and more areas become unusable for agriculture, we'll need to work out how future city dwellers are going to be fed.

Speaker 3

00:08:01 - 00:08:31

Hello, I'm Jess Davis. I'm a professor of sustainability and an environmental scientist at Lancaster University. And I've become really interested in urban soils and their potential for supporting food growing. There's a lot of passionate opinions out there about urban food growing, with some people saying you know that we need to grow everything in our gardens and others suggesting we ought to have skyscrapers or underground tunnels filled with indoor farms. Other people just saying oh they're pipe dreams and that can't happen.

Speaker 3

00:08:32 - 00:08:45

And so with our research we wanted to come in and try and look at this objectively and explore what could we grow in urban places and what might that do for how much food we have available, what it could do for our environment and what it could do for our health and wellbeing.

Speaker 1

00:08:45 - 00:08:54

Jessica, when you were investigating the green spaces in towns and cities that could be used to grow food, what kind of land were you looking at?

Speaker 3

00:08:54 - 00:09:46

So we wanted to do this national scale analysis and we considered all the spaces. So we looked at all the residential gardens and private grounds, sports pitches, parks, small green verges at roadside, school grounds, and even cemeteries. So we looked at that all together, and we found that if we used all of that space, then we could grow the equivalent of more than 4 times what we currently grow and import for crops well suited to the UK, so not considering things like bananas. We also looked at lots of different towns and cities across Great Britain and we found that they could all be self-sufficient in fruit and veg production, growing enough to meet dietary requirements for the inhabitants of those places. But of course we really wouldn't want to use all that land for food growing but it just goes to show if we just use a small amount of that land it could be a very meaningful boost to our supplies.

Speaker 1

00:09:46 - 00:10:03

And obviously agricultural land is in part used because it's good soil to grow on, but that isn't really always the case in cities and towns, is it? So how did you explore the potential productivity of the spaces and soils that you were looking at.

Speaker 3

00:10:03 - 00:10:31

So we brought all the data together that we could find on urban food growing yields from across the world. And what that analysis showed was that urban food growing could be just as productive or even more productive than conventional growing. In our towns and cities, people are there to tend that space much more intensely and you can have multiple crop rotations and you can manage it more closely than you would within a big field setting.

Speaker 1

00:10:31 - 00:10:41

It's pretty impressive, but you're not going to use all your green spaces for food. We do need them for other things. So how should we decide where to grow?

Speaker 3

00:10:41 - 00:11:17

I think it needs to be a dialogue. It needs to be something we talk about as communities and decide what we want to do with this precious space that we have and think bigger and be more creative. We've explored this in Lancaster, working with our city council and working with local people here and bringing together data that helps us understand where these spaces that we could use might be. But local people had a lot of knowledge about what's going to work and what's not going to work. And there's lots of ways we could support people, families, communities to grow food and open up space for that.

Speaker 3

00:11:17 - 00:11:36

There's a right to grow bill at the moment that's being championed by Incredible Edible founder, Pam Moorhurst, that's calling for legislation that would mean that local authorities would have to look at their land holding and open up space for communities to grow food and that we have a right to access to land for growing.

Speaker 1

00:11:36 - 00:11:42

Jessica, if you were to design a futuristic city keeping this all in mind, what would it look like?

Speaker 3

00:11:42 - 00:12:16

For me, I think I'd really love to incorporate diversity into it. We need to get away from a monoland use mindset where we use spaces for just 1 thing. You know, we need to introduce diversity into our spaces to get the most from them. You know, maybe flowers for pollinators and food growing around the school football pitch, solar panels and veg beds on large rooftops together, orchards that are lining our canals and walkways. We can bring these different purposes together in all these spaces and of course I'd want them to be all supported by healthier city soils.

Speaker 1

00:12:19 - 00:12:44

So in the city of the future we all grow food. The thing is, not everyone in cities is even near a green space, let alone has 1 of their own. Several studies have found that people from ethnic minorities and lower socioeconomic backgrounds don't have as much access to green spaces as wealthy white people. And as Ben told me back in Colchester, this isn't anything new.

Speaker 2

00:12:45 - 00:13:26

Cities are very contested places and actually when it comes to green spaces those unlikely spots may be kind of you know commons, forests, allotments are places that have been fought for and contested all the time and you find it in Indian cities now where trees are being taken away, green spaces are being lost. Giving people access to that kind of space that they can shape for themselves is really important. And so we should revive that idea and put that sort of in the heart and soul of urban regeneration. Now, throughout history, the nice green thing has been the preserver of the rich. The poor have always suffered from having the least amount of nature in the cities.

Speaker 1

00:13:30 - 00:13:47

To understand more, I called Professor Diane Jones-Allen, an author and landscape architect at the University of Texas at Arlington, whose research looks at environmental justice. She described how racial inequalities were built into cities across the US.

Speaker 4

00:13:47 - 00:14:52

Post-slavery as people of color began to move around they were placed into certain areas and it was government sanction racism and so they would make these maps for each city. You can actually look them up, but these maps of the city would be color-coded, and green areas would be areas that were good for you as a real estate agent, because that's who usually used them to send white people. Then you would direct people of color, blacks, Latinos, whoever was the minority that's not in favor, you would direct them to the red areas. And then, you know, the next thing that happened is the development of the freeways, which landed right in the middle of communities of color and divided them and also increased segregation. A great example is the Treme community in New Orleans when they dropped I-10 and it replaced the longest stand of oak trees in North America.

Speaker 4

00:14:54 - 00:15:08

And that freeway, besides dividing the community, having very negative economic impact, it had very negative environmental impact on people because instead of trees now they had carbon.

Speaker 1

00:15:09 - 00:15:37

This is something called redlining and recent studies have shown that redlined areas in the US are on average 5 degrees warmer than non-redlined areas. Studies have also found that redlined cities have higher levels of air pollution. So these are parts of the city that need to be rewilded and regreened first. But it isn't necessarily as straightforward a process as you might imagine. It has to be done in the right way.

Speaker 4

00:15:38 - 00:16:08

So green gentrification is the idea that redevelopment, property values, and the shifting of populations that happen often when new green infrastructure comes, when there are new parks and new greenways, right? Because property values go up. So often when developers see, oh, there's a capital improvement happening here. They're redoing the streets, they're putting in a greenway, they're putting in a new park. So then they start to look for investment.

Speaker 4

00:16:08 - 00:16:26

That's a good area to develop condos, right? So then people end up getting displaced. The challenge is how do you let those that have lived around and have suffered not having this improvement, how do you let them stay?

Speaker 1

00:16:27 - 00:16:33

How do you green without gentrifying? According to Diane, there's 1 critical point.

Speaker 4

00:16:33 - 00:16:55

The key is community participation. But the engagement has to be more than, here's the plan, what do you think? Goodbye and go do it. It has to be really working with the community to make sure they're participating not just in the design and planning but all the way through and participating in the benefit.

Speaker 1

00:16:56 - 00:17:26

That could be introducing more social housing, implementing rent controls, getting locals involved in nature projects, like the community food growing Jessica described. So, the city of the future. It's diverse in terms of its people, transport and of course nature. It's wild, messy and directed by the communities that live there. A far cry from the sleek and shiny cities we're often sold as the next big thing.

Speaker 1

00:17:27 - 00:17:29

Back to Ben in Colchester.

Speaker 2

00:17:30 - 00:18:02

When you think of the future and what we call smart cities, I mean the smartest cities of the future are going to be ones that use nature and green infrastructure for their own protection. I went to the world's most advanced, was touted as the world's most advanced smart city which is called Songdo in South Korea which was built as a green city, as a kind of like hyper smart, digitally organized city. It was supposed to be the city of the future. And even in this sort of like hyper advanced smart city, the weeds were already poking through the concrete. And I found that the most exciting thing I saw there.

Speaker 2

00:18:02 - 00:18:20

Forget all the gadgets and things like that. Singapore may be a good, simultaneously a good and bad example. Singapore is a place that's been hugely impacted by human use. A lot of its native vegetation stripped away. But even in that very densely packed city state, a huge amount of investment is being put into making it greener.

Speaker 2

00:18:20 - 00:18:43

Green walls, green buildings, roof gardens, urban farming, lots of kind of greenness woven into the city. And that's what makes it a modern city, I think, not its kind of gleaming skyscraper. I think we're always besotted with cities as places of technological control, but I think we should really see them as something else you know something that where nature does play a part in offering us some kind of protection and mitigation from the worst effects of what we've done to the planet.

Speaker 1

00:18:45 - 00:19:11

A huge thanks to Professor Diane Jones-Allen, Professor Jessica Davies and to Ben Wilson. We've put a link to Ben's book Urban Jungle on the podcast web page at theguardian.com. And that's it for today. The producer was me, Madeline Finlay, the sound design was by Joel Cox and the executive producer was Ellie Burey. We'll be back on Thursday.

Speaker 1

00:19:12 - 00:19:11

See you then. This is The Guardian.