Engaging at Scale with 21st Century Urbanization Prepared by - PowerPoint PPT Presentation

Towards an Evidence-Based Urban Agenda Engaging at Scale with 21st Century Urbanization Prepared by Professor Shlomo Angel, Director, NYU Urban Expansion Program, for presentation at the University of Zurich, 18 August 2016

The Challenge: Urban planners and policy makers are likely to fail to engage with 21st Century urbanization. We now fail at our core mission: to guide and organize future urban expansion by laying out public works in advance of development. Our “master plans” are easily ignored because they have no teeth, and our “smart city” districts, built from start to finish, make no difference. As long as we are confused about our core mission, we will not convince our publics to give us the necessary tools — the jurisdictions, the powers and the budgets — to do our job.

Message 1: Urban expansion is ‘invisible’ and therefore typically underestimated : Between 1990 and 2015, the area occupied by cities in more developed countries increased by a factor of ; in less developed countries it increased by a factor of .

Measuring urban expansion : Between 1800 and 2015, the population of Paris, France, increased 22-fold – from 500,000 to 11 million – while its area increased 250-fold, from 11 km 2 to 2,800 km 2 (animation using historical maps and satellite imagery).

Mega-Regions: The UN Population Division divides the world into two mega-regions: More Developed Countries and Less Developed Countries. The Atlas of Urban Expansion allows us estimate changes in urban extent in these mega-regions.

Population Growth and Urban Expansion : The population of cities in Less Developed Countries doubled between 1990 and 2015, while their urban extents increased by a factor of 3.5 (left). In parallel, the population of cities in More Developed Countries increased by a factor of 1.2 between 1990 and 2015, while their urban extents increased by a factor of 1.8 (right).

Density Decline : Urban extent densities (blue) in Less Developed Countries – 3.3 times higher than densities in More Developed Countries in 1990 – declined at an average annual rate of 2.1% between 1990 and 2015 (left). In More Developed Countries densities declined at 1.5% during this period (right). Urban land consumption per capita (red) in these regions increased at similar rates.

Urban Extent (2 x GDP) = 1.56 GDP R 2 = 0.77 Urban Extent and City GDP : Differences in urban density and land consumption per capita in these two mega-regions are largely explained by differences in their cities’ per capita incomes. A simple relationship exists between urban land consumption per capita and GDP per capita: On average, doubling GDP per capita increases land consumption by a factor of 1.5.

Lagos, Nigeria, 2015 Paris, France, 2015 Population: 11.4 million Population: 11.2 million City GDP: US$58 billion City GDP: US$557 billion Urban Extent: 850 km 2 Urban Extent: 2,803 km 2 Urban Extent Density: 134 p/ha Urban Extent Density: 40 p/ha Land Consumption per Capita: 71 m 2 Land Consumption per Capita: 251 m 2 In 2015, Paris had almost the same population but 10 times the GDP as that of Lagos. As a consequence Paris had 3.5 times the urban extent of Lagos.

Estimating future urban expansion : Between 2015 and 2050 the urban population in Less Developed Countries will increase by 2.35 billion, or 18 times the expected increase of 130 million in the More Developed Countries. We can begin to understand how much urban expansion this will entail by looking at past urban expansion.

Estimating future urban expansion : Between 2015 and 2050 the urban extent in More Developed Countries will increase by a factor of 1.9 at the current rate of increase in land consumption, by a factor of 1.5 at half the current rate, and by a factor of 1.1 if land consumption remains constant.

Estimating future urban expansion : Between 2015 and 2050 the urban extent in Less Developed Countries will increase by a factor of 3.7 at the current rate of increase in land consumption, by a factor of 2.5 at half the current rate, and by a factor of 1.8 if land consumption remains constant.

Underestimating Urban expansion in practice: In 2000, the built-up area of Zhengzhou, China was 286 km 2 (light orange). According to its master plan approved in 2009, its built-up area was expected to reach 400 km 2 by 2020. It reached 612 km 2 by 2015 (dark red).

1 4 Message 2: To work at scale, city officials must (1) estimate their future expansion correctly, (2) plan and secure the rights-of-way for future arterial roads , (3) ensure that adequate lands are allocated to streets , and (4) protect key future public open spaces , so as to organize their urban peripheries in a productive, inclusive and sustainable way before development occurs .

1 5 Gouverneur Morris, 1811 Commission Chairman Louis Risse, Chief Engineer, Topographical Department. New York’s ambitious expansion plans: The 1811 Commissioners’ Plan expanded the city 7 -fold and the 1900 Board of Public Improvement Plan expanded it again, this time 9-fold.

1 6 Ildefons Cerdá Barcelona’s ambitious expansion plan: Ildefons Cerdá’s Ensanche Plan of 1859, expanded its built-up area 9-fold .

1 7 Assembling the evidence on global urban expansion: We identified the universe of 4,231 cities that had 100,000 people or more in 2010; we then focused on a stratified global sample of 200 cities, and within these cities on a set of randomly chosen 10-hectare locales .

1 8 The 2010 Universe of cities on a map of world regions.

1 9 The UN Sample of Cities and the eight world regions.

2 0 Pre-1990 (tan), 1990-2000 (orange) and 2000-2015 (red) expansion zones (left), and randomly selected 10-hectare locales in Accra, Ghana.

2 1 Locales in the pre-1990 area (left) and expansion area (right) of Accra, Ghana, 2015.

22 Finding 1: Most of the residential fabric in the expansion areas of cities (1990-2015), especially in less developed countries, is unplanned and disorderly, taking place in defiance of municipal plans or regulations.

23 Residential Fabric Laid Out Not Laid Out Formal Informal Layout Layout From left to right: Formal layout: Minneapolis, USA; Informal layout: Lagos, Nigera; Not Laid Out: Mumbai, India.

24 Extreme values of the shares of residential areas formally laid out: the expansion areas of Sydney, Australia on left (87%) and of Lahore, Pakistan on right (30%).

25 100%� Occupia on� 90%� Pre-1990� 80%� 1990-2015� Before� 70%� Out� 60%� Laid� 50%� Fabric� 40%� Residen al� 30%� of� 20%� Share� 10%� 0%� East� Asia� Southeast� South� and� Western� Sub-Saharan� La n� Europe� and� Land-Rich� World� and� the� Asia� (SEA)� Central� Asia� Asia� and� Africa� (SSA)� America� and� Japan� (E&J)� Developed� Pacific� (EAP)� (SCA)� North� Africa� the� Countries� (WANA)� Caribbean� (LRDC)� (LAC)� The shares of residential fabrics laid out before occupation in the pre-1990 areas (gray) and in the expansion areas (orange) in the universe of 4,231 cities by world regions, 2015.

26 100%� 90%� Occupa on� Pre-1990� 80%� Before� 1990-2015� 70%� Out� 60%� Laid� 50%� Fabric� Residen al� 40%� 30%� of� Share� 20%� 10%� 0%� <$3,000� $3,000-$8,000� $8,000-$20,000� $20,000+� World� The shares of residential fabrics with formal layouts in the pre-1990 areas (green) and in the expansion areas (tan) in the universe of 4,231 cities by city GDP per capita, 2015.

27 110%� 100%� � Out� 90%� Laid� Formal� Layouts� is� 80%� that� Informal� Layouts� 70%� Not� laid� out� Area� 60%� Residen al� 50%� 40%� of� 30%� Share� 20%� 10%� 0%� Before� 1900� 1900-1930� 1930-1960� 1960-1990� 1990-2015� The change in the shares of residential areas with formal layouts ,informal layouts and no layouts over time in a representative set of 30 cities.

28 Finding 2: The paucity of arterial roads in the expansion areas of cities is failing to connect them effectively to metropolitan labor markets, making cities less productive, less inclusive, and less sustainable.

29 Toronto, Canada’s bus and streetcar network, located largely on its arterial road grid, 2010.

30 The absence of arterial roads in a 60 km 2 section of northwest Bangkok, Thailand, 1984.

Road� 100%� 31 90%� Arterial� 80%� of� Distance� 70%� 60%� Walking� 50%� 40%� Within� 30%� Area� Share of area w/in walking distance of arterial 20%� of� roads – wide and narrow – in the sample, post- 10%� Share� 1990 and pre-1990. 0%� (EAP)� (SEA)� (SCA)� (WANA)� (SSA)� (LAC)� (E&J)� (LRDC)� World� Africa� Japan� Pacific� Asia� Asia� Caribbean� Countries� Africa� Southeast� Central� and� Sub-Saharan� the� North� Europe� the� and� Developed� and� and� Asia� and� South� America� East� Asia� Land-Rich� Western� La n� The share of built-up area within walking distance (625m) of an arterial road in the pre-1990 areas (orange) and expansion areas (blue) in the universe of 4,231 cities by world regions, 2015.