Lessons from slums show why our cities need to go on a resource diet

The Mumbai slum Dharavi in 2007. Image: Getty.

Cities are the epicentres of human activity. They cover less than 2 per cent of the earth’s land surface but generate about 70 per cent of GDP and house more than half the human population. The importance of cities is only going to increase in coming decades as another 2.5bn people move to urban centres.

This intense production and consumption requires huge quantities of natural resources. Cities account for more than 60 per cent of global energy use, 70 per cent of greenhouse gas emissions and 70 per cent of global waste. Current practices are depleting the Earth’s finite resources, changing its climate and damaging its natural ecosystems. With our planetary life support system in the red, we need to put cities on a serious resource diet.

Resources efficiency in the New Urban Agenda

The New Urban Agenda adopted at the Habitat III conference outlines a vision for sustainable urban development. These global guidelines, along with the related UN Sustainable Development Goals, recognise the need to use resources more efficiently.

Habitat III included a number of sessions on resource efficiency and associated tools and initiatives. Organisations such as UNEP, UN-Habitat and the European Commission and its research centres typically led these events. The New Urban Agenda includes many references to efficiency and reduced consumption in cities.

We must now act urgently to translate words into actions. This will ease pressure on ecosystems and produce a range of co-benefits, including health, wellbeing and resilience.

How do we create more resource-efficient cities?

Cities use resources directly, such as burning fossil fuels for electricity and transport. However, indirect uses, such as water for growing food crops, are much wider-reaching.

It can be overwhelming to consider the resources used for all goods, processes and infrastructure in cities. Yet it is possible to measure this using a systems approach. Instead of considering components in isolation, the entire city is considered as an open system, connected to others.

This perspective ensures a much broader understanding of complex relationships between scales, resource flows, the built environment, socio-economic factors and ecological outcomes.

There are tools that embrace a systems perspective. For example, the urban metabolism approach considers cities as ecosystems, across which flows of resources (such as energy or water) are measured. Life cycle assessment measures resource use through the entire production, consumption and degradation process of a good or service.

These approaches have been successfully applied at various scales such as cities, neighbourhoods and buildings. This reveals that we are using more resources than shown by traditional assessment techniques (see this example on building energy efficiency regulations).

But measurement without action has no impact on the ground. How can these tools be used to transform our cities?

Recent research enables us to map the quantities of materials in buildings and predict when and where we can reuse or recycle these. Here a map of estimated steel quantities in each building of Melbourne, Australia. Source: authors' own; left: Google and TerraMetrics; right: Stephan, A. and Athanassiadis, A. (In Press) Quantifying and mapping embodied environmental requirements of urban building stocks, Building and Environment.

Many initiatives are targeting urban resource efficiency. The circular economy paradigm is a good example, where materials are reused, upcycled and recycled. It demonstrates that waste is a human concept and not an inherent property of cities. Waste does not exist in natural systems.

A range of projects by UNEP, the European Commission and other organisations support local resource efficiency initiatives and encourage local governments to implement related regulations. Blogging, data visualisation and disseminating research all help promote the adoption of resource efficiency concepts. In addition to the pioneering work of groups such as metabolism of cities, the uptake of open data is helping with this.

Learning from those who already live on less

Informal settlements provide interesting lessons in resource efficiency. Construction materials in these settlements are typically not very durable. However, because they are in short supply, they are constantly reused or repurposed, almost never discarded.

Other residents often reuse replaced materials, such as metal sheets, or store them for later use. This practice avoids additional resource use to produce new materials.

Although informal slum areas are often the focus of “upgrading” and improvement, lessons learnt in these settings can enhance material flow management and reduce waste elsewhere in cities.

Informal settlements like Karail next to Banani Lake in Dhaka, Bangladesh, can offer lessons in resource efficiency, waste reduction and material flow management to most cities. Image: Alexei Trundle.

Co-benefits of resource efficiency

More resource-efficient cities tend to result in better health outcomes. For instance, encouraging walking, cycling and public transport instead of car use can reduce fossil fuel consumption and greenhouse gas emissions, and improve population health through increased physical activity.

Food systems that promote consumption of fresh, local produce can benefit both the environment and nutrition. Energy-efficient housing reduces energy and water use and can improve occupants’ health at the same time.

Resource efficiency can also contribute to urban resilience. Nature-based solutions use relatively few non-renewable materials to increase resilience to environmental change and natural disasters. For example, a park can be designed to be flooded during storms or a tsunami, reduce the urban heat island effect, support urban ecosystems and provide areas for community activities, recreation and urban agriculture.

Efficiency can also ensure that redundancy – a core principle of resilience – is built into urban systems. This means resources can be repurposed in the event of an unanticipated shock or stress. For example, during the recent blackout in South Australia, a household with solar battery storage was able to maintain power for 12 hours “off grid”.


Working together for better solutions

Although these steps move cities in the right direction, more action from governments, the private sector and civil society is needed to transform our growing urban footprints.

Focusing solely on resource efficiency may neglect opportunities to generate co-benefits across sectors and will not provide robust solutions. We need to look at the entire city as a system and work together, across all disciplines, with effective and strong governance structures that support integrated policy definition and long-term implementation. If we don’t, we might simply shift a problem from one area to another, increase resource demand elsewhere, or create social divisions and tensions.The Conversation

Strong leadership, political stability, effective institutions and awareness-raising among citizens are vital factors for success. Urban resource efficiency is critical, but it should be considered along all other pressing issues highlighted in the New Urban Agenda.

This article was written by a team of researchers at the University of Melbourne. André Stephan is a postdoctoral research fellow; Alexei Trundle a PhD candidate in the Australian-German Climate & Energy College; Dave Kendal a researcher with the Royal Botanic Gardens Victoria (ARCUE); Hayley Henderson a PhD candidate in urban planning; Hesam Kamalipour a PhD candidate and research assistant in urban design, and Melanie Lowe a research fellow at the McCaughey VicHealth Community Wellbeing Unit of the Melbourne School of Population and Global Health.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

Was the decline in Liverpool’s historic population really that unusual?

A view of Liverpool from Birkenhead. Image: Getty.

It is often reported that Liverpool’s population halved after the 1930s. But is this true? Or is it a myth?

Often, it’s simply assumed that it’s true. The end. Indeed, proud Londoner Lord Adonis – a leading proponent of the Liverpool-bypassing High Speed 2 railway, current chair of the National Infrastructure Commission, and generally a very influential person – stood on the stairs in Liverpool Town Hall in 2011 and said:

“The population of Liverpool has nearly halved in the last 50 years.”

This raises two questions. Firstly, did the population of the City of Liverpool really nearly halve in the 50 year period to 2011? That’s easy to check using this University of Portsmouth website – so I did just that (even though I knew he was wrong anyway). In 2011, the population of the City of Liverpool was 466,415. Fifty years earlier, in 1961, it was 737,637, which equates to a 37 per cent drop. Oops!

In fact, the City of Liverpool’s peak population was recorded in the 1931 Census as 846,302. Its lowest subsequent figure was recorded in the 2001 Census as 439,428 – which represents a 48 per cent decline from the peak population, over a 70 year period.

Compare this to the population figures for the similarly sized City of Manchester. Its peak population also recorded in the 1931 Census as 748,729, and its lowest subsequent figure was also recorded in the 2001 Census, as 392,830. This also represents a 48 per cent decline from the peak population, over the same 70 year period.

So, as can be seen here, Liverpool is not a special case at all. Which makes me wonder why it is often singled out or portrayed as exceptional in this regard, in the media and, indeed, by some badly briefed politicians. Even London has a similar story to tell, and it is told rather well in this recent article by a Londoner, for the Museum of London. (Editor’s note: It’s one of mine.)

This leads me onto the second question: where have all those people gone: London? The Moon? Mars?

Well, it turns out that the answer is bit boring and obvious actually: after World War 2, lots of people moved to the suburbs. You know: cars, commuter trains, slum clearance, the Blitz, all that stuff. In other words, Liverpool is just like many other places: after the war, this country experienced a depopulation bonanza.


So what form did this movement to the suburbs take, as far as Liverpool was concerned? Well, people moved and were moved to the suburbs of Greater Liverpool, in what are now the outer boroughs of the city region: Halton, Knowsley, St Helens, Sefton, Wirral. Others moved further, to Cheshire West & Chester, West Lancashire, Warrington, even nearby North Wales, as previously discussed here.

In common with many cities, indeed, Liverpool City Council actually built and owned large several ‘New Town’ council estates, to which they moved tens of thousands of people to from Liverpool’s inner districts: Winsford in Cheshire West (where comedian John Bishop grew up), Runcorn in Halton (where comedian John Bishop also grew up), Skelmersdale in West Lancashire, Kirkby in Knowsley. There is nothing unique or sinister here about Liverpool (apart from comedian John Bishop). This was common practice across the country – Indeed, it was central government policy – and resulted in about 160,000 people being ‘removed’ from the Liverpool local authority area.

Many other people also moved to the nearby suburbs of Greater Liverpool to private housing – another trend reflected across the country. It’s worth acknowledging, however, that cities across the world are subject to a level of ‘churn’ in population, whereby many people move out and many people move in, over time, too.

So how did those prominent images of derelict streets in the inner-city part of the City of Liverpool local authority area come about? For that, you have to blame the last Labour government’s over-zealous ‘Housing Market Renewal Initiative’ (HMRI) disaster – and the over enthusiastic participation of the then-Lib Dem controlled city council. On the promise of ‘free’ money from central government, the latter removed hundreds of people from their homes with a view to demolishing the Victorian terraces, and building new replacements. Many of these houses, in truth, were already fully modernised, owner-occupied houses within viable and longstanding communities, as can be seen here in Voelas Street, one of the famous Welsh Streets of Liverpool:

Voelas Street before HMRI implementation. Image: WelshStreets.co.uk.

The same picture after HMRI implementation Image: WelshStreets.co.uk. 

Nonetheless: the council bought the houses and ‘tinned them up’ ready for demolition. Then the coalition Conservative/Lib Dem government, elected in 2010, pulled the plug on the scheme. 

Fast forward to 2017 and many of the condemned houses have been renovated, in a process which is still ongoing. These are over-subscribed when they come to market, suggesting that the idea was never appropriate for Liverpool on that scale. 

At any rate, it turns out that the Liverpool metropolitan population is pretty much the same as it was at its peak in 1931 (depending where the local borough boundaries are arbitrarily drawn). It just begs the question: why are well educated and supposedly clever people misrepresenting the Liverpool metropolis, in particular, in this way so often? Surely they aren’t stupid are they?


And why are some people so determined to always isolate the City of Liverpool from its hinterland, while London is always described in terms of its whole urban area? It just confuses and undermines what would otherwise often be worthwhile comparisons and discussions. Or, to put it another way: “never, ever, compare apples with larger urban zones”.

In a recent Channel 4 documentary, for example, the well-known and respected journalist Michael Burke directly compared the forecast population growths, by 2039, of the City of Liverpool single local authority area against that of the combined 33 local authority areas of Greater London: 42,722 versus 2.187,708. I mean, what bizarre point is such an inappropriate comparison even trying to make? It is like comparing the projected growth of a normal sized-person’s head with the projected growth of the whole of an obese person, over a protracted period.

Having said all that, there is an important sensible conversation to be had as to why the populations of the Greater Liverpool metropolis and others haven’t grown as fast as maybe should have been the case, whilst, in recent times, the Greater London population has been burgeoning. But constantly pitching it as some sort of rare local apocalypse helps no one.

Dave Mail has declared himself CityMetric’s Liverpool City Region correspondent. He will be updating us on the brave new world of Liverpool City Region, mostly monthly, in ‘E-mail from Liverpool City Region’ and he is on twitter @davemail2017.