Sustainability, and the urban ecological footprint

Overview

Sustainable development, what the environmental dimension of sustainability involves in a settlement and what the social dimension of sustainability involves in a settlement.

What you need to know

Answer each one before you reveal it.

Questions from this subtopic

Each one with the model answer underneath.

1. 1

   What is sustainable development?

   Model answer

   Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs. It contains two ideas at once: needs, particularly the needs of the poorest, and limits, set by the capacity of the environment to supply resources and absorb waste. It is conventionally analysed under three headings, environmental, social and economic, and a settlement is only sustainable if it performs adequately on all three, because a scheme that is environmentally excellent but unaffordable, or profitable but polluting, will not last.

2. 2

   Explain what the environmental dimension of sustainability involves in a settlement.

   Model answer

   Living within environmental limits. In practice that means reducing energy use in buildings and transport and shifting the remainder to low-carbon sources; cutting greenhouse gas emissions and local air pollutants; reducing water consumption, leakage and abstraction; minimising waste and diverting it from landfill; protecting and connecting green space, soils and biodiversity; reusing previously developed land and existing buildings rather than consuming countryside; managing surface water to reduce flood risk and pollution; and reducing car dependence through the layout of the settlement itself.

3. 3

   Explain what the social dimension of sustainability involves in a settlement.

   Model answer

   Meeting the needs of all the people who live there, now and in the future. That means enough decent, affordable housing of the right types and tenures; access for everyone, including those without a car, to jobs, schools, health care, shops and green space within a reasonable distance; safe streets and public spaces that people are willing to use; health and wellbeing, including freedom from fuel poverty and poor air quality; a mix of ages, incomes and household types rather than segregation by income; opportunities for people to take part in decisions about their area; and equity, both between groups today and between the present generation and the next.

4. 4

   Why can environmental and social aims conflict in a settlement, and give examples.

   Model answer

   Because measures that reduce environmental impact can impose costs on particular groups. Building at high density reduces land take and travel distances and supports public transport, but reduces private garden space and can worsen overlooking and noise if poorly designed. Congestion charging and clean air zones cut emissions but bear most heavily on lower-income drivers of older vehicles who may have no realistic alternative. Building to very high energy standards raises construction costs, which can reduce the number of affordable homes a scheme delivers. Remediating a contaminated brownfield site is expensive, and the cost is often met by reducing the affordable housing contribution. Recognising these trade-offs, and asking who gains and who pays, is what separates a serious evaluation from a list of good intentions.

5. 5

   Why is the economic strand still necessary if the aim is environmental and social sustainability?

   Model answer

   Because nothing survives that cannot be paid for. Residents need local jobs and incomes or the settlement becomes a commuter dormitory with high transport emissions and weak local services. Developers must find schemes viable or they will not build them, and the standards will be negotiated away. Public transport, parks, recycling systems and district heating all carry running and maintenance costs that must be funded for decades, and schemes that are built and then not maintained fail. Economic viability is therefore a condition for the other two strands rather than a competitor with them.

6. 6

   What features make a settlement more sustainable in practice?

   Model answer

   A compact, mixed-use form so that daily needs are within walking distance; densities high enough to support frequent public transport, focused around interchanges; energy-efficient buildings and retrofit of the existing stock, with low-carbon heat and local renewables; water efficiency and sustainable drainage; waste minimisation, high recycling and food waste collection; a connected network of green and blue space serving drainage, cooling, biodiversity and recreation at once; local employment and services so trips are short; a genuine mix of housing tenures and sizes including affordable homes; safe, overlooked streets designed for walking and cycling; reuse of brownfield land and existing buildings; and structures for community involvement so that residents shape and then maintain the place.

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