Good Cities 2: Ecology & the Restorative City
Bosco Verticale (‘vertical forest’), Milan
By Tim Thorlby
6 mins
This is the second blog in a series looking at what makes a ‘good city’. Taking the idea of the 15-minute city as a starting point this blog explores the ecology of cities and what ‘greening’ them could mean and why it matters.
1 – Introduction
What is a ‘good city’? What does it look like? Who does it benefit? Why should we care?
Given that over 80% of us live in towns and cities in the UK it is an important question and the answer we give will shape our lives, our impact on each other and, indeed, the planet.
The first blog in this four-part series introduced the idea of the ‘15-minute city’. I’m not suggesting that this provides a full answer to the question – life is rarely that neat - but I think it’s a pretty good starting point. Each blog in this series is exploring one of the four features of the 15-minute city – proximity, ecology, fairness and democracy. This second blog is looking at the ecology of the city.
2 – The 15-minute city, briefly
My first blog explained the ideas behind the 15-minute city and so I will not repeat all of that here, just give a brief reminder.
The ’15-minute city’ is a simple concept, drawing on longstanding ideas about what a ‘liveable’ city might look like. The idea is that in our towns and cities our daily requirements – work, shops, schools, healthcare, etc – should be easily reached within a 15-minute walk or bike ride. The aim is to make cities healthier, more environmentally sustainable and improve the quality of life for all residents, rich and poor. Some have described it as a ‘return to a local way of life’ with less long-distance commuting and less reliance on the car and a more decentralised city pattern. The aim is to spend less time commuting between places and more time actually in those places.
No-one is proposing that we demolish our urban areas and start again, or introduce draconian policies, so the challenge is to retro-fit such ideas onto existing places, which is why making it happen would require some creativity and time and no doubt move forward in fits and starts.
There are four dimensions to the 15-minute city which I am considering in turn in this series of blogs:
Proximity
Ecology
Solidarity (or fairness)
Participation (or democracy)
The rest of this blog will explore ‘ecology’ and what role this has within a ‘good city’.
3 – City ecology
What do we mean by the ‘ecology’ of a city? Here, I mean it in the broadest sense, encompassing all of the environmental aspects of our urban living:
Our buildings – the concrete, tarmac and bricks that make up our towns and cities represent an impact on the environment both in terms of where the raw materials were sourced from and also how they have been assembled to construct places for us to use.
Local nature – urban areas often have more wildlife than you might suppose, including everything from insects and rodents to the local trees and parks.
Our ambient environment – this is the immediate environment as we experience it, through air quality, water quality, even background noise.
Atmosphere – like it or not, our actions in one place usually have a wider impact on the atmosphere in some way, through pollution or burning fossil fuels which deliver emissions and drive climate change.
In thinking about how we impact upon urban ecology - and how it impacts on us – as well as how we might do things differently, I want to look at three core elements – an ABC of ecology:
Ambient environment – air and water quality, noise, etc
Biodiversity – the nature and extent of local flora and fauna
Carbon – the emissions driving climate change
4.1 – A is for Ambient environment: restoring humanity
There is plenty of evidence to show that the design of our urban areas impacts directly upon our experience of it, and our resultant physical and mental health. What makes us happier in our towns and cities is things like these:
Green spaces make us happy – spaces where we can enjoy nature, get exercise and meet people. There is surprisingly good evidence about the benefits of urban green spaces for our overall health, including lower anxiety, stress and depression and even relieving the symptoms of some psychiatric disorders[1]. Trees, gardens, parks and greenery are definitely good for us.
Social spaces make us happy – sociable spaces where we can meet friends or make new ones, whether cafes, community centres or parks. Research suggests that even saying ‘hello’ with people we don’t know well can lift our mood and promote a sense of belonging to a place.
Quieter neighbourhoods make us happy - where our lives are not dominated by noise and where our sleep is not interrupted by traffic noise or neighbours. A single noisy motorbike roaring past at night (about 80 dB in volume) can wake up to 30% of the neighbourhood[2]. In the UK, noise levels are almost entirely unregulated in practice. In Germany, they have laws about acceptable noise levels at night (50 dB, as you’re asking), so it seems you can regulate it.
Cleaner air makes us happy – fresh air is better for physical and also mental health. Poor air quality is associated with lower levels of mental wellbeing, particularly amongst children and young people[3]. Currently in the UK, it is not great in many of our towns and cities and its particularly damaging to our children.
Safer streets make us happy – feeling safe in the street unsurprisingly lowers our stress levels and builds confidence; no-one likes a menacing neighbourhood.
The Centre for Urban Design and Mental Health[4] has published an intriguing book called ‘Restorative Cities’, exploring how urban design can promote better mental health and, well, just make us happier.
It is quite clear that our physical environment influences our behaviour and mood and can therefore encourage, or discourage, certain habits. Things like well designed, good quality green spaces that people are drawn to can encourage sociability, a sense of belonging, even kindness to strangers.
I like the idea of a ‘restorative city’ – literally a city that is thoughtfully designed to restore us as human beings, to build us up, to make us healthier and happier. And isn’t a greener, cleaner, safer and more attractive neighbourhood something we all want anyway?
4.2 - B is for Biodiverse cities
Rural areas are naturally more bio-diverse than urban areas and probably always will be, but as a predominantly urban nation, the diversity and abundance of nature within our towns and cities remains a factor in the UK’s overall environmental vitality. It can also convey benefits to city dwellers. For example, lots of greenery and green spaces help to keep urban areas cool in the summer and reduce rainfall runoff, helping to reduce local flooding. And who doesn’t like to watch the local chaffinches or woodpeckers fluttering around their neighbourhood?
Well, first the bad news. The UK’s official Biodiversity Indicators[5] monitored by the government continue to show decline:
Relative abundance - The government recognises 2890 ‘priority’ species of all kinds in the UK and monitors the relative abundance of 228 of these (almost 10%). From 1970 to 2021, these species showed a 63% decline in the UK.
Distribution – the government also monitors the distribution of these same priority species to assess how many places they can be found in across the UK. From 1970 to 2018, there was a 4% decline. This decline masks a mix of trends, with one in five species doing well, but one in three in decline.
Now the more surprising news.
Taking England as an example, only 8% of our green and pleasant land is actually urban (less than you thought?) Within these urban areas, there is also more evidence of nature than you might think. Across England, 30% of urban areas are actually public green space, like public parks, commons, allotments, golf courses and playing fields. A further 30% of the urban area is accounted for by domestic gardens – although not all of these are entirely ‘green’ if they are paved and patioed[6]. But, the majority of our urban area (60%) is actually not all ‘built’ but in some way ‘green’ or ‘green-ish’.
We can thank previous generations for this, leaving us a legacy that is not just concrete and tarmac but with many spaces protected for essential greenery, making our towns and cities more livable. Urban planning gets a bad press but is often the last line of defence between a small green space and a bulldozer. Next time a politician promises to dismantle the planning system, perhaps remember this.
Urban tree cover is also more than you might think. A number of projects are underway to map urban trees in the UK, including Urban Tree Cover and i-Tree Eco.
The evidence so far suggests than an average of 16% of urban areas are covered with trees (‘canopy cover’), on public and private land. By way of example, i-Tree Eco surveys have shown that Greater Manchester has 11.3 million trees (four trees for every Mancunian!) providing nearly 16% canopy cover of their urban area, with 192 different species of tree recorded[7]. Boffins have estimated that this removes 847 tonnes of air and water pollution every year for the benefit of the people of Manchester. Greening our cities provides immediate environmental and health benefits.
Just by the by, I recently had a look at the trees in my own neighbourhood. I live in a fairly dense urban neighbourhood in north London but I still found nearly 30 different species of tree within 100m of our flat, including some rather unusual ones. (I spent a lot time staring at oddly shaped leaves whilst flicking through my book of trees!)
The point here is not that everything in our towns and cities is fine, as it clearly is not, but also that not everything is terrible either. We can see and feel the benefits of biodiversity in our cities, and the challenge is to increase this. Could we have the greenest cities in Europe? Why not?
4.3 - C is for Carbon: how do we decarbonise our cities?
Much has already been written on this already, so I will keep this short.
There are three ways that we continue to rely upon fossil fuels in our towns and cities:
Fuel for transport
Fuel for heating our homes and workspaces
Emissions from the process of constructing new buildings
If we are to reach Net Zero by 2050, we will need to make changes to how we live in our towns and cities. The good news is that this may also make life more enjoyable for a lot of us.
a) Decarbonising transport in cities
Living in urban areas is usually more energy efficient than country living – people share buildings (e.g. living in flats) and they live closer to shops and work and rely more on public transport. The carbon footprint of an urban resident is typically a third less than a country dweller.
Moving towards a 15-minute city model would strengthen this, bringing different types of activity closer to together and designing urban areas where walking, cycling and public transport become more attractive options.
One of the key changes required to embed this approach is to allow higher density neighbourhoods with a greater mix of uses – more ‘urban villages’ and less low density housing-only suburbs. The argument for this is well made in a recent report by the Centre for Cities[8]. The report also includes an interesting chart showing which towns and cities are denser and they are amongst some of the most popular places to live in the UK; many people want this and buy into this, but we have a house-building industry wired to build suburban housing as the safest way to maximise their corporate profits. That is for another blog though.
The significant expansion of home and hybrid working since the pandemic may help to accelerate this change as more people spend more time in their neighbourhoods.
b) Decarbonising heating
How we heat and insulate our homes is a huge factor in carbon emissions. We are getting better at this, but over 60% of the UK’s homes still do not meet energy efficiency targets (ratings of A to C). This is not only an environmental challenge it is also costing many of us a fortune – energy efficient homes cost thousands of pounds less to heat each year.
On this, we already know what we need to do, it is already measured and technologies exist for us to use. We know what to do. Government really needs the political will to make it happen and get on with it. It will cost money up front in terms of incentives and grants, but it will save many of us a small fortune in the years to come, as well as reducing emissions.
c) Decarbonising construction
The most environmentally friendly building is the one that already exists.
Any new building that is constructed requires a surprising amount of carbon emissions, not so much during the building process itself but in the manufacturing and transportation of the constituent materials like bricks, steel, glass and cement. This is called ‘embodied carbon’ and every time we demolish a building and replace it, the carbon footprint is enormous. There is currently no real Government policy towards managing this, according to the Green Building Council[9].
We need to be much slower to demolish buildings in this country. You don’t even need planning permission most of the time. Maybe you should? Could demolition be taxed, given its huge environmental impact? We need to be more creative in reusing existing buildings. When we construct new buildings they should also be designed for the longer term, not just for 30 years.
There is much to think about here for a new generation of architects and developers.
5 – Called to choose
I think the theology for greening our cities is perhaps not so difficult to unpack or too controversial.
I described a simple theology of ‘creation care’ in an earlier blog on farming, which I won’t repeat here. In summary, God has declared his creation to be “very good”, he notes that it all continues to belong to him so that we are “tenants” not owners and he instructs us to “take care” of it. Anyone who uses Christian theology to give support for pollution or exploitation of the planet is either wilfully misusing it or not really paying much attention to it.
Most interestingly to me, in the context of today’s blog, is the biblical idea that if we take care of the land, then it takes care of us. There is a feedback loop in our planetary ecosystem, not lost on the Bible’s ancient writers. The rather dry book of Leviticus includes instructions about leaving fields fallow on a regular basis “then the land will yield its fruit”. The Old Testament regularly returns to the idea that ‘we reap what we sow’.
This blog highlights research evidence that where we pollute our cities and build carelessly it comes back to bite us in the form of physical and mental ill health.
The idea of a ‘restorative city’ is an attractive one to me, and has strong theological resonance, because it builds upon the idea that we should be intentionally designing, building and managing our towns and cities in order to be healthy and green places not just for the good of the planet but also because it is better for us too. If we chose to build cities that are ecologically richer, it would bring life to us too.
I live in a dense urban neighbourhood on the second floor of a building and don’t have a garden. But there is a small patch of common grass at the front of our building along the edge of which my young son and I plant flowers every spring (‘sneaky gardening’ he calls it). They bring a patch of colour and life to an area of tired earth. It’s a small thing, but it makes us happy. And as we walk past those flowers every day they remind us that life is a choice.
5 – Next time…
In the next couple of blogs, I will take a closer look at the remaining themes of the 15-minute city:
Solidary/fairness
Participation/democracy
Thanks for reading!
This blog was written by Tim Thorlby. Please sign up for the free monthly email if you’d like to know about future blogs.
Notes
[1] Numerous studies provide evidence reviews. For example: Roe, J. (2016) Cities, Green Space and Mental Wellbeing, Environmental Science: Oxford Research Encyclopaedias. Available at: https://oxfordre.com/environmentalscience/display/10.1093/acrefore/9780199389414.001.0001/acrefore-9780199389414-e-93 Also: Greenspace Scotland (2008) Health Impact Assessment of greenspace: A Guide. Available at: https://www.scotphn.net/wp-content/uploads/2015/11/Health-Impact-Assessment-of-greenspace-a-Guide.pdf
[2] Some fascinating evidence about urban noise can be found at: https://earthjournalism.net/resources/noise-pollution-managing-the-challenge-of-urban-sounds
[3] Bhui, K, et al (2023). Air quality and mental health: Evidence, challenges and future directions. BJPsych Open, 9(4), E120. Available at: https://www.cambridge.org/core/journals/bjpsych-open/article/air-quality-and-mental-health-evidence-challenges-and-future-directions/FF3A143292CD1783BA7DC7B744573C5C
[4] www.urbandesignmentalhealth.com
[5] National Biodiversity Network, State of Nature Report 2023. Available at: https://stateofnature.org.uk/wp-content/uploads/2023/09/TP25999-State-of-Nature-main-report_2023_FULL-DOC-v12.pdf
[6] Environment Agency, Chief Scientist’s Group (2021) The state of the environment: the urban environment | Available at: https://www.gov.uk/government/publications/state-of-the-environment/the-state-of-the-environment-the-urban-environment
[7] From p110 of this enormous tome: Woodland Trust (2021) State of the UK’s Woods and Trees 2021 | Available at: https://www.woodlandtrust.org.uk/media/51705/state-of-the-uks-woods-and-trees-2021-thewoodlandtrust.pdf
[8] Quinio, V. & Rodrigues, G. (2021) Net zero? Decarbonising the city, Centre for Cities | Available at: https://www.centreforcities.org/wp-content/uploads/2021/07/Net-Zero-Decarbonising-the-City.pdf
[9] UK Green Building Council (2022) Decarbonising the built environment: Government policy scorecard | Available at: https://ukgbc.org/resources/decarbonising-the-built-environment-government-policy-scorecard/