IB ESS Topic 8.2 HL

Ecological Urban Planning

• Guiding Question

  • To what extent are urban systems similar to natural ecosystems? How can reimagining urban systems create a more sustainable future?

• Ecological Urban Planning

  • Principles: urban compactness, mixed land use and social mix practice.

• Task

  • Ecological Urban Planning: Follow the instructions on the website and in the document below, in order to create a sustainable city, based on the concept of ecological urban planning.

• Key advantages of practices

  • Reduced urban sprawl

  • Less car dependency

  • Reduced energy consumption

  • Better public transport

  • Increased accessibility and social equality

  • Environmental justice: Avoiding social inequality in access to green areas is a matter of environmental justice.

Reduced urban sprawl

• Mainly occurs in High-Income Countries (HIC) and Middle-Income Countries (MIC).

• Use green belts that surround a city or penetrate through a city; development of the natural environment is largely controlled.

• Low-density developments may be allowed (e.g., parks, hospitals, cemeteries), but large-scale residential developments are not permitted.

• Housing developments are diverted to other existing towns or new towns are created elsewhere.

• Largely occurred due to the increase in private car ownership and the construction of low-density suburbs.

• To prevent urban sprawl:

  • Housing in urban areas needs to be built at higher densities

  • There will need to be improved public transport

Less car dependency

• Encourage use of public transport, cycling, and micromobility using electric bikes and scooters.

• Aim is not to ban cars but to direct cars to areas where alternative forms of transport are reduced (e.g., remote areas or on the periphery of towns/cities).

• Measures include:

  • Increase vehicle tax

  • Congestion charges

  • Low emission zones

• Examples:

  • London: funds from congestion charges are used to fund public transport. Reducing car parking spaces and increasing the cost of parking spaces. Road closures to non-local traffic in Waltham Forest reduced daily vehicle flow by $22\%$ and was supported by $74\%$ of residents.

  • Singapore: residents need a permit to own a car and are charged for using certain roads. Charges depend on vehicle type, time of day and day of the week.

  • Mexico City: pedestrianisation led to a $30\%$ increase in commercial activity and a $96\%$ fall in crime.

Reduced energy consumption

• Cities use $66\%$ of the world’s energy and create about $75\%$ of the world’s greenhouse gases.

• Energy problems in urban areas include increasing demand, ageing infrastructure, volatile energy markets (e.g., the Ukraine–Russia conflict), and climate change.

• Energy supplies need to be secure, affordable and have a net-zero status.

• Helsinki, Finland – Decarbon-Home Project

  • Aims: reducing energy consumption and switching to renewable energy.

  • Goal: achieve net zero by $2040$.

  • Outcomes: greenhouse gas emissions reduced by $33\%$ since 1990; economic growth increased by $65\%$; per capita emissions decreased by $50\%$.

  • Total energy usage remained unchanged despite population growth.

  • Renewable energy now accounts for around $25\%$ of energy production.

  • Project also targets vulnerable groups (elderly and immigrant groups), adapting housing to be more energy efficient.

Better public transport

• Curitiba, Brazil:

  • Rapid population growth in the 1950s; population now over $2\,\text{million}$.

  • Avoided problems associated with rapid urban growth; residents prefer public transport; the environment is used rather than changed.

• Structural approach to road and transport:

  • Road network and public transport system have structural axes.

  • Interdistrict and feeder bus routes complement express bus lanes along the structural axes.

  • Improvements focus on speed of journey and convenience of passengers.

• Features include:

  • Single fares allowing transfers from express routes to interdistrict and local buses.

  • Extra-wide doors for quick boarding.

  • Double and triple-length buses to handle rush hour loads.

  • Bus routes and bicycle paths integrated with parks to weave urban life together.

  • Bus systems are more economical than a subway; bus companies are paid by $\text{KM of road they serve}$ rather than by the number of passengers.

Increased accessibility

• Definition: Allows people to reach a greater number of locations and activities in a shorter amount of time.

• Impacts:

  • More opportunities for employment, social interactions, healthcare and retail.

  • Improves quality of life.

• Accessibility can be measured by the time or cost to reach a place.

Increased social equality

• Social equality means all population groups are equal in terms of rights and status.

• Vulnerabilities include:

  • Low income

  • Lack of employment opportunities

  • Ill health

  • Poor educational achievement

  • Limited access to housing and services

  • High crime rates and poor living environments

Models For Sustainability

• Societies are developing systems to address urban sustainability using models such as a circular economy or doughnut economics to promote sustainability within the urban system.

• Linear model of urban systems: “take, make and waste.” Cities consume about $75\%$ of the world’s natural resources and generate about $50\%$ of the world’s waste.

• Traditional economic theory describes a circular flow of goods and money but does not account for negative environmental externalities (raw materials and energy use or waste production).

• The circular model can lead to cities that are:

  • Thriving: reduced congestion, waste and costs.

  • Liveable: improved air quality and reduced pollution.

  • Resilient: reduced reliance on raw materials and keeping products in use.

• Amsterdam, Holland

  • Aims to reduce primary raw materials in industry and buildings by $50\%$ by $2030$ and to have a full circular economy by $2050$.

  • 2018 data: $8.5\times 10^6$ tonnes of industrial and commercial waste and $1.1\times 10^6$ tonnes of household waste.

• Amsterdam: Doughnut model

  • Social indicators: $40\%$ of the population are overweight, $49\%$ with moderate to high risk of anxiety or depression. In 2017, $15\%$ of residents reported discrimination, with $39\%$ of incidents related to ethnicity or skin colour, and $29\%$ related to nationality.

  • Accessibility: city aims to be accessible to everyone via public transport in a safe and sustainable way.

  • Mobility: $665{,}000$ bike journeys are made daily; routes on trains, buses and trams are integrated with a simple fare structure.

• Singapore

  • Adopted a compact, biodiversity-rich approach to urban planning.

  • Green areas expanded from $36\%$ of the island in 1970 to $47\%$ in 2020; has $72\text{ ha}$ of roof-top gardens – expected to triple by $2030$.

  • total green space: $4000\text{ ha}$; ecological services include climate and flood regulation, space for recreation, and increased biodiversity.

  • Singapore is believed to be home to between $23{,}000$ and $28{,}000$ terrestrial species.

Task - Green Architecture

• Task instruction

  • Follow the instructions on the website to research and explain how an example of green architecture works.

• Green architecture overview

  • Minimizes harmful effects of construction projects on human health and the environment.

  • Aims to safeguard air, water and earth by choosing environmentally friendly building materials and construction practices.

  • Combines new and indigenous knowledge systems, vernacular architecture, bio-based materials and circular construction.

• Focus and lifespan

  • Focuses on minimizing a building's environmental impact throughout its lifespan.

  • From using recycled materials during construction to incorporating energy-saving features and promoting rainwater collection, prioritizes resource efficiency.

  • Designs aim to lessen humanity's footprint by harmonizing structures with their natural surroundings.

• Energy, resources, and pollution (overview of strategies)

  • Energy: ventilation systems with efficient heating and cooling; energy-efficient appliances and lighting; renewable energy resources (e.g., $solar$ and $wind$).

  • Natural resources: water-saving features; designing landscape to maximize solar energy; re-use of older buildings; efficient use of space; use of responsibly harvested wood.

  • Pollution: more vegetation (trees) to filter pollutants; reduced carbon emissions through renewable energy; less concrete, more use of clay and vegetation; use of sustainably harvested wood; reduced harm to the natural environment.

• Disadvantages of green architecture

  • Limited availability of materials.

  • Higher initial costs due to expensive materials and technology.

• Barajeel: Arabic Wind Tower Houses

  • Barajeel: a traditional form of housing that creates cross-ventilation and cooling in buildings.

  • Common in North Africa and West Asia; used for over 3,000 years.

  • Popularity increased in the 21st century to increase ventilation and reduce air conditioning costs; wind is caught and transferred into buildings; air filters may be required to trap dust and insects.

  • Example site: Bluewater Shopping Centre in Dartford, UK.

• How wind towers work

  • Warm air rises and escapes through the top; denser air sinks toward the ground.

  • Wind towers contribute to natural ventilation and cooling.