Sustainability, Land Use and Ecological Footprints

What makes city living sustainable?

A sustainable city must do more than reduce pollution. It needs to provide homes, jobs and services while using resources carefully and protecting the environment. Quality of life concerns residents’ wellbeing: whether they have suitable housing, good health, access to work and education, and pleasant surroundings.

These aims are connected. Better public transport can reduce car use while helping people reach jobs. Energy-efficient housing can reduce energy consumption while making homes cheaper to heat. However, an environmentally improved neighbourhood is not necessarily affordable to everyone. Evaluating a strategy means considering its benefits, costs and who can access them.

Reusing London’s developed land

London’s housing demand creates pressure to build more homes. One response is to redevelop brownfield sites, rather than build on previously undeveloped land. Battersea Power Station and the Olympic Park are London examples of previously developed sites converted to include new housing.

Redevelopment can remove derelict buildings and improve the local environment. However, former industrial land may need costly clearance and treatment before it is safe to build on. Contamination, asbestos and rubble can increase costs and generate waste. These costs can also push up the price of the finished housing. Reusing land therefore helps environmental sustainability, but does not automatically solve the affordability problem.

Housing that reduces resource use

BedZED is a sustainable housing development built on a brownfield site. Most of its building materials came from within a 35-mile radius, although its windows were an exception. Local sourcing reduces the distance materials must travel. Green roofs provide habitat for wildlife, while a car club gives residents access to shared vehicles rather than requiring every household to own a car.

East Village in Stratford was converted from the accommodation used by athletes and officials during the London 2012 Olympic and Paralympic Games into a residential neighbourhood. It combines housing with local shops and services, connections to train and bus services, green roofs and about 10 hectares of parkland. Nearby services reduce the need for long journeys, and public transport provides alternatives to driving.

By June 2014, 2,528 homes had been completed and handed over, including 1,204 affordable homes. These included social rent, intermediate rent and shared ownership, rather than one uniform type of lower-cost housing. Providing different housing options can help more households access the neighbourhood, although the label ‘affordable’ does not mean every household can afford them.

Reported water use at East Village is 50% below average and energy use is 30% below average. These reductions show how housing design can lower demand for resources. Nevertheless, successful developments in particular neighbourhoods do not by themselves meet housing needs across the whole city. Both environmental performance and affordability matter.

Employment, education and health at East Village

Regeneration can create employment as well as improve buildings. The post-Games transformation of East Village involved 6,000 workers from November 2012, including plumbers and electricians. This illustrates how redevelopment generates demand for construction skills and paid work. However, construction work is time-limited: the number involved does not demonstrate that permanent jobs were created for local residents.

Chobham Academy, opened in September 2013, brought education into the new neighbourhood. A nearby school helps families access education, while education can develop skills that improve future employment opportunities. The presence of a school is an immediate improvement in services; any longer-term effect on earnings takes time.

The Sir Ludwig Guttmann Health and Wellbeing Centre provides GP and pharmacy services for East Village and the wider local community. Local healthcare improves access to treatment and advice, supporting residents’ wellbeing. Its wider-community role also means that benefits are not confined to people living in the new homes.

Together, these measures show why sustainable regeneration needs more than energy-efficient housing. Residents also need opportunities to earn an income, learn and obtain healthcare.

Transport: improving access and air quality

London’s strategies include Santander cycle hire, the Congestion Charge, low-emission zones and investment in hybrid and electric buses.

These approaches tackle different problems. Cycle hire provides an alternative to driving for suitable journeys. The Congestion Charge discourages some car journeys in the charging area. Low-emission zones discourage the use of more polluting vehicles, while cleaner buses reduce pollution from public transport.

The potential gains include cleaner air, lower resource consumption and better access to services. Their effectiveness depends partly on whether residents have convenient alternatives to driving. A charge alone does not provide a bus route; transport restrictions and investment work best together.

Waste reduction and greener surroundings

London’s waste strategies include ReLondon’s work to increase recycling and FoodSave’s efforts to prevent food waste and use surplus food. Drinking fountains encourage reusable bottles. Recycling allows materials to be used again, reducing the demand for new resources; preventing waste avoids resource use in the first place.

London has set targets including recycling 65% of municipal waste by 2030 and reducing household waste by 20% per household. These are aims, not proof of completed improvements. Their success depends on participation and the systems available to collect and process waste.

Green spaces also improve urban living. The Greener City Fund supports community tree planting and green-space projects. Thames Barrier Park, opened in 2000, provides wildlife, picnic and play areas. Such spaces combine environmental benefits with opportunities for recreation. Their contribution to quality of life depends on residents being able to reach and use them.

Judging the range of strategies

A strong judgement considers a combination of strategies. East Village illustrates how housing, employment during redevelopment, education, healthcare, transport and green space can work together. Environmental improvements alone cannot address all aspects of disadvantage.

Brownfield redevelopment is valuable because it reuses land and can deliver homes and services together. Its limitations include clearance costs, affordability and the temporary nature of construction employment. Transport and waste strategies can reach beyond individual developments, but depend on accessible services and public participation. The wider challenge is to extend benefits across London, rather than improve only selected neighbourhoods.

Identifying land use from satellite images

Satellite images show surface features from above. To interpret them, first check the scale, north arrow, image date and whether the colours are natural or false colour. The spatial resolution determines whether individual buildings are distinguishable or whether only broad built-up areas can be identified.

Next, combine colour, shape, pattern and texture. In natural-colour imagery, densely built areas commonly appear grey, silver, brown or red, depending on their building materials. Vegetation is usually green, and water is often dark blue or black. Neither colour nor darkness alone establishes a land use: shadows can resemble water, and vegetation changes with the season.

For example, imagine two built-up patches. One contains many small roofs arranged along repeated streets; the other contains a few large rectangular roofs beside broad access routes. The first pattern is consistent with a residential zone, while the second could indicate warehouses or industrial premises. These are provisional interpretations: a large roof might also belong to a shopping centre. An open vegetated area could be recreational land, but its shape and surrounding features would help distinguish a park from farmland.

Transfer this method to an actual image by matching visible patterns to a reference map and local knowledge. Identify broad zones, support each identification with observable clues, and check alternatives. Satellite imagery can reveal building patterns and green space, but it cannot on its own establish residents’ incomes, housing affordability or the exact activity inside a building.

What an ecological footprint measures

A city’s resource demands extend far beyond its boundary. Residents consume food, timber and other products grown elsewhere, and their energy use produces carbon dioxide. An ecological footprint measures the biologically productive land and sea area needed to support that consumption and absorb associated carbon dioxide emissions.

Different areas have different productivity. A hectare of cropland and a hectare of forest do not supply the same resources. Footprint accounting therefore converts their demands into global hectares (gha), a common unit adjusted to world-average biological productivity. A footprint of 5 gha means demand equivalent to the output and services of five global hectares, not necessarily five hectares located beside someone’s home.

Calculating residents’ footprints

The basic method begins with consumption. For a resource such as a crop, divide the amount consumed in a year by the amount produced per hectare in a year:

$$\text{Area required (ha)} = \frac{\text{annual consumption (tonnes/year)}}{\text{annual yield (tonnes/ha/year)}}$$

The resulting physical hectares are converted into global hectares using productivity factors. Carbon dioxide emissions are also translated into the productive area needed to absorb them. Adding the converted demands gives a person’s total ecological footprint. Raw hectares of different land types should not simply be added as though their productivity were identical.

Once residents’ footprints are expressed in comparable global hectares, a group’s total is the sum of its residents’ footprints. Dividing that total by the number of residents gives the average footprint per resident.

For a simple calculation, suppose two city residents have already-calculated footprints of 3 gha and 5 gha. Their combined footprint is $3 + 5 = 8\text{ gha}$, and their average is $8 \div 2 = 4\text{ gha per resident}$. The average describes the group but hides differences between individuals.

Connecting footprints to London’s strategies

Energy-efficient homes and alternatives to fossil-fuelled car journeys can reduce the carbon-related part of residents’ footprints. Recycling paper reduces demand for newly harvested timber, while preventing food waste reduces resources used to produce food that is never eaten. Reducing consumption generally offers greater savings than relying only on recycling afterwards.

An ecological footprint is useful for comparing demand on biological capacity, but it is not a complete measure of sustainability or quality of life. It does not directly capture every toxic pollutant, health outcome or inequality. A lower footprint should therefore be considered alongside housing affordability, employment and access to services.

Sustainable London: recall the examples

• Brownfield redevelopment: Battersea Power Station and the Olympic Park. Reuses developed land, but clearance and contamination can raise costs.
• BedZED: brownfield site, mostly locally sourced materials, green roofs and a car club.
• East Village: public transport, local services, green roofs and about 10 hectares of parkland. Reported water use: 50% below average; energy use: 30% below average.
• Affordable housing: East Village had 1,204 affordable homes among 2,528 completed homes by June 2014.
• Employment: 6,000 workers involved in East Village’s post-Games transformation from November 2012; construction work is temporary.
• Education and health: Chobham Academy opened in September 2013; Sir Ludwig Guttmann Health and Wellbeing Centre provides GP and pharmacy services.
• Transport: Santander cycle hire, Congestion Charge, low-emission zones, hybrid and electric buses.
• Waste: ReLondon, FoodSave and reusable-bottle drinking fountains. Recycling target: 65% of municipal waste by 2030.