In the age of the city

Herbert Girardet

An urbanising world

• Cities define human existence and impacts in the 21st century

• As centres of human interaction and innovation, they are the heartland of national economies, financial systems and cultural life – and of resource consumption

• As countries urbanise, village people moving to the city typically increase their per capita resource use fourfold

• Are limits to growth also limits to urbanisation?

• Crucially: cities are subject to the second law of thermodynamics – they can’t escape the clutches of entropy

• The challenge is to reconfigure cities into systems and places that work for both people and planet

18th c. Birmingham: an age of innovation

• Lunar Society 1760s to 1810s – science and enterprise

• Steam technology, electricity, ceramics, metallurgy, medicine, botany, anatomy, surveying, chemistry, geology, chemistry, astronomy, engineering , zoology, architecture, art

• Steam engines, railway carriages, bicycles, spinning technology, machine tools, printing

• Nails, nuts and bolts, screws, brass goods, pumps, bedsteads, buttons, pen nibs, toys, silver plate, medical instruments, jewellery, guns, coins, buckles, swords, clocks, glass, paper; chocolate

Source: Nakicenovic

2009

Structures and processes

• City planners are primarily concerned with urban structures and spaces

• But in many ways the processes that make cities work are more important in understanding urban dynamics and impacts

• Crucially, the metabolism of cities is not confined to the urban environment:

• It is increasingly global, and reaches to all corners of the planet

London

London’s Ecological Footprint

• Population: 7,500,000 people

• Surface area: 158,000 ha

• Area required for food production: 1.2 ha per person: 8,400,000 ha

• Forest area required for wood products: 768,000 ha

• Land area required for carbon sequestration

• = bio-fuel production: 1.5 ha per person: 10,500,000 ha

• London’s footprint: 19,700,000 ha = 125 times London’s surface area

• Britain’s productive land: 21,000,000 ha

• Britain’s surface area: 24,400,000 ha

© Herbert Girardet , 1995

Shanghai Pudong 1978

Shanghai Pudong 2013

Adelaide

‘Regenerative’ Adelaide 2013

• 40% electricity supply from wind and solar• 120,000 PV roofs on 600,000 houses = 250 MW peak

• PV roofs on most public buildings

• Solar hot water systems mandated for new buildings

• 3 million trees planted on 2000 ha for C02 absorption and biodiversity

• 15% reduction of C02 emissions since 2000

• Water sensitive urban development

• 180,000 tonnes of compost made from urban organic waste

• 20,000 ha of peri-urban land used for vegetable and fruit crops

• Reclaimed waste water and urban compost used to cultivate this land

• Large scale-building tune-up programmes across the city region

• 60% carbon emissions reduction by municipal buildings

• Construction of Lochiel Park Solar Village with 106 eco-homes

• Thousands of new green jobs

Urban ecology

Study of -

• living organisms and their relationship to each other within an urban environment

• benefits of vegetation and green spaces for urban populations

• collective impacts of urban populations on environments beyond city limits

• ways and means of creating a mutually beneficial, regenerative relationship between urban populations and ecosystems