1.4_xumei_bai[1].pdf
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Urbanization and
Urban System Dynamics
Professor Xuemei Bai
Fenner School of Environment andSociety, ANU
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Figure 2. The change in the human
enterprise from 1750 to 2000 (28).
The Great Acceleration is clearly
shown in every component of the
human enterprise included in the
figure. Either the component was
not present before 1950 (e.g., foreign
direct investment) or its rate of
change increased sharply after 1950
(e.g., population).
(Source: Steffen et al, 2007)
Urbanization as key
indicator for accelerating
human enterprise
1. Urbanization in the Anthropocene
More than half the
Earths population are
urban dwellers
Cities as the center for
economic growth,
innovation, resource
use, and
environmental impacts
Battle for sustainability
to be won or lost in
cities
Urban vs rural population(Source: Grimm et al 2008) Map 5: Growth rates of urban agglomerations, 1970-2011. These maps indicate
that the annual growth rates of urban agglomerations in the past (1970-2011 period)
were higher than the growth rates that are projected for the future (2011 to 2025period). The growth of urban agglomerations will slow down, as many of them have
already reached a population of 1 million or more or have become mega-cities with 10
or more million inhabitants.(Source: United Nations, Department of Economic and Social Affairs, Population Division: World Urbanization
Growth Rates of Urban Agglomerations, 1970-2011.
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Figure 3 Rapid urban
expansion of Shenzhen
City from 2000 to 2007
based on remote
sensing image
interpretation. Redcolor for urban land,
yellow for bare land,
green for land withvegetation, blue for
water body.
ETM+ image on Nov. 1st 2000, TM
image on Sep. 15th 2000, ETM+
SLC-off composite data on Dec.7th and Nov. 30th 2007 are used
for this comparison.
(Bai et al, forthcoming)
1. Background
Neck breaking speed in building
15 storey fastest
building of hotel built
in just six days- world
record, Changsha,
China (http://ddlax.hubpages.com/hub/
15-storey-hotel-built-in-just-six-days)
30-story building built
in 15 days (http://www.youtube.com/watch?
v=Hdpf-MQM9vY&annotation_id=annota
tion_418374&feature=iv)
220-story 838m
World tallest building
in 90 days?12
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And Demolishing
Average building lifespan
10+ in Shenzhen
80% of world heavy cranes
in coastal China
40% of construction
materials used in China
Construction material
demand will exceed supply(Shen et al, 2005)
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Five Lake Hotel in Nancang City, 13years old, blasted on Feb. 6th, 2010.
Change of ownership, upgrading.
The Bund Community in Wuhan, 4 years
old, blasted on March 30th, 2002. Violation
of flood regulation plan.
http://www.zerohedge.com/article/china-proudly-demolishing-
buildings-completed-pursuit-great-housing-bubble-perpetual-engine
2. Drivers and Impacts of Urban Growth
Primary driver:
- Job opportunity and aspiration for better life- Push and pull factors
Policy factor:- Concurrence of urbanization, industrialization and economic
growth
- Significant urban contribution to national economy- High income countries often have higher urbanization level
=> National policy to promote urbanization for economic growth
Does urbanization bring about economic growth?(Bloom et al, Science, 2008)
Urbanization as multifaceted phenomenon: Demographic
Landscape
Social
Cultural
Political/institutional
Environment
Demographic urbanization data known to beproblematic, and lacks comparability across countries
Demographic indicator not sufficient to deny causalrelationship between urbanization and economic growth.(Bai et al , 2012)
Urbanization is more than people
moving into cities!
Figure 2 Spatial distribution of Chinese cities included in analysis.Panel U1 (1990-1998) consists of 174 cities.
Panel U2 (1997-2006) consists of 135 cities.
Panel U3 (1990-2006) consists of 121 cities that appear in both U1 and U2 panel.
(Source: Bai et al, EST, 2012)
2. Drivers and Impacts
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Figure 4 Average annual growth of GDP per capita, built-up area,
and population of 135 Chinese cities during 1997-2006.
(Source: Bai et al, EST 2012)
2. Drivers and Impacts
Positive Feedback
1)Larger cities tend to gain more income and richer citiestends to expand more
2) There is a long-term bi-directional causality betweenurban built-up area expansion and GDP per capita atboth city and provincial level, and a short-term bi-directional causality at provincial level.
3) A positive feedback between landscape urbanizationand urban and regional economic growth in China.
(Bai et al, Environmental Science&Technology, 2012)
2. Drivers and Impacts
Policy Implications
1) Urbanization, if measured by a landscape indicator,does have causal effect on economic growth in China,both within the city and with spillover effect to theregion.
2) Urban land expansion is not only the consequences ofeconomic growth in cities, but also drivers of such
growth.3) Under its current economic growth model, it might be
difficult for China to control urban expansion withoutsacrificing economic growth.
4) Chinas policy to stop the loss of agricultural land, forfood security, might be challenged by its policy topromote economic growth through urbanization.
- (Bai et al, Environmental Science&Technology, 2012)
2. Drivers and Impacts
Urban landuse is often surrounded by
arable land. Beijing-Tianjin-Tangshan
area, China (shown in 10km radius in the
figure). (Source: Tan et al 2005)
Disproportionate Impact on Arable Land
In China, up to 80% of
all agricultural land
loss over the last
decade was convertedinto urban landuse.
Between 1997 and
2006, more than
12,000sqkm of land
was converted into
urban built up area.(Bai et al 2012)
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Currently about 1% of earth surface is urban.
Some forecast suggest this could be tripled by
2030.
(Source: United Nations, Department of Economic and Social Affairs, Population
Division: World Urbanization Prospects, the 2011 Revision. New York 2012)
Implications for Agriculture
While the absolute amount doesnt seem
significant, urbanization has significant
implications in terms of:
Direct impact on the amount of arable land
Strong, fundamental drivers
Indirect impacts on productivity and rural community
Changed quantity and structural mix of demand for
food
Stronger pressure on food production concentrated tosome vulnerable regions such as China and India
Bai Crawford Fund Conf., Oct
9th, 2012
Fig. 5 Transformation of four communities over past 6 decades. (Huang et al,
Environmental Science and Policy, 2 012)
Urbanization Impacts on Rural Community
(Huang et al, Environmental Science and Policy, 20 12)
Changing Vulnerability of rural community in relation to
landuse change
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But in other areas, where
the locals can seize the
opportunity, tremendous
increase in social/economic
capital in peri-urban areas.
(CCICED, 2012)
Eco-tourism in Chengdu rural villages
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Urbanization Impact of on Rural Community
- Five Golden Flowers in Chengdu - Urban EcosystemsCities as driver and responder to environmental change
(Grimm et al 2008, Science)
3. Urban Processes and Dynamics
Global Impacts of Cities
Although urban population growth over the past century
occurred on less than 3% of the Earths surface, theimpact has been global, with
78% of carbon emissions,
60% of residential water use, and 76% of wood used for industrial purposes attributed to cities.
(Source: Grimm et al, Science, 2008)
3. Processes and Dynamics
Urban System
Input
NaturalResource (Food,Energy, Water,Other Materials)CapitalInformation
Urban Systems Structures
and Functions
Urban Land and WaterEcosystem ServicesUrban InfrastructureDistribution of GoodsProvision of Urban ServicesIndustrial ProcessesUrban Planning
Urban GovernanceUrban life style
Urban System
Outputs
Industrial Products andServicesKnowledgeWastes and Other
Emissions
Urban Systems Performance Indicators
Social (e.g. employment, liveability, health and well being, culture and heritage, equality)Economic (e.g. competitiveness, productivity)Environmental (e.g. air and water pollution level, noise level, resource efficiency etc)Governance (e.g. participation and inclusion)
Figure 2 Integrated urban metabolism and urban system performance indicators
(Source: Bai and Schandl, 2011. In RutledgeHandbook of Urban Ecology, 2010)
3. Processes and Dynamics
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Cities as Open System
Can we live off solar energy in cities? (According to Global Energy Assessment, 2012) ?%
External dependency:
Household Consumption based CO2 emission
accounting in Xiamen city:
70% - upstream to provide for cities
17% - urban service & infrastructure
13% - emission from direct activity
(Lin et al, PLoS ONE 2013)
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Discharge as solidhuman excreta
Sludge
dischargeDischarg
e as
treated
Marginally left in human
body (ignored)
Reclaimed
water
To landfill or
a ricultural
P fertilizer
input into
Food
Edibl
e
Inedible Solid
P inflow intourban system
through food
consumption
Food waste
Pass throughouturban area and to
P remained
in urban
area
Non-urban
Urban
Landfill
Discharge as
untreated sewa eP flow outside
Othersremainedin urban
Figure 2 Conceptual model of urban dietary P flow into and out of
urban system and mass balance calculation.
(Source: Li, Bai et al, Journal of Industrial Ecology, 2011)
3. Processes and Dynamics
Figure 6 Relationship between per capita disposable
income of urban residents and indicators related to
dietary P flow in provincial capital cities of China
(data for the year 2006).
(Source: Li, Bai et al, Journal of Industrial
Ecology, 2011)
(B)
(E
)
(C) (D
)
(A)
3.ProcessesandDynamics
Table 3-1 Causes and impacts of major types of ur ban environmental issues
Type Typical Issues Causes Major Impacts
Spatial Extend of
Impacts
Type I:
Poverty
related issues
Low access to safe
water, lack of
sanitation facilities,
organic pollution of
water bodies
Low infrastructure,
rapid urbanization,
income disparity
Sanitation related
health impacts, such
as diaries, infections
local
Type II:
Rapid growth
related issues
Air poll ution (SOx,
particulate etc), water
pollution (heavy
metallic subjects,
BOD, COD)
industrial solid waste
pollution, etc.
Rapid
industrialization, low
rate of emission
treatment, lack of
effective management
typical industrial
pollution disaster,
Minamata Disease,
Onsan Disease;
deterioration of
regional ecosystem,
local and regional
Type III:
Wealthy
lifestyle
related issues
CO2 emission, NOx
concentration,
municipal waste,
Dioxin, etc.
High consumption
lifestyle, low local
incentive for
improvement
Global warming,
chemical ingredient
and dioxin caused
abnormality in infant,
over-extraction of
resources, etc.
regional and global
(Source: Bai and Imura, 2000)
3. Processes and Dynamics
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SO2 concentration in Korean and Japanese cities
0.000
0.050
0.100
0.150
0.200
0.250
0.300
1950 1960 1970 1980 1990 2000 2010
Year
SO2concentration(mg/m3)
3. Processes and Dynamics
(Source: Bai 2003)
Urban Environmental Evolution (1)
Cities are complex systems subject to
constant change, the process of which can be
viewed as a dynamic evolutionary process
Urban environmental profiles of cities are
diverse, but there are certain commonalities
in the evolutionary trajectories among
different cities (Source : Ba i2003)
3. Processes and Dynamics
Urban Environmental Evolution (2)
However, the environmental evolution of
cities exhibit a strong non-linearity in their
trajectories, instead of following a fixed,
stylized pattern;
Each trajectory is shaped by a unique
combination of endogenous and exogenous
forces, reflecting both pressures from outside
the system and the responses from within the
city. (Source : Ba i2003)
3. Processes and Dynamics
4. Urban Sustainability Experiments and
Transition
If cities are evolving systems, is it possible to
intervene and alter the future trajectory towards
sustainable end?
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Changing System of Practice
Change is always challenging!
Inertia
stickiness
path dependency
Lock-in
Nevertheless, there are front-runners and
successful examples
Large number of urban best practicesdocumented
4. Experiments and Transition
Solar energy use in Rizhao, China
4. Experiments and Transition
Sustainability Experiment
Sustainability experiments are planned initiatives
that embody a highly novel socio-technical
configuration likely to lead to substantial
(environmental) sustainability gains.
Small initiatives in which the earliest stages of a process of
socio-technical learning takes place.
Typically bring together new networks of actors with knowledge,capabilities and resources, cooperating in a process of learning
(Berkhout et al, 2010)
4. Experiments and Transition
Single Case vs. Multiple Case
Single case learning often treated as too context
specific or anecdotal in academic debate
Lack of systematic, comprehensive analysis
attempting to identify commonalities across largenumber of individual cases
The need for understanding key characteristics
and emerging common patterns, and extracting
transferable knowledge across cases
4. Experiments and Transition
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Research Questions
What contributes to the success of a goodpractice?
Are there commonalities and emerging patterns
across cases?
What are the determining factors and mechanisms
shaping these patterns?
What are the sound analytical approaches for
identifying them?
(Bai et al 2010)
4. Experiments and Transition
Pathway ofExperiments
Triggers
ActorsBarriers
Linkage
s
Analyzing innovative practices in urban sustainability:
Conceptual framework
(Source: Based on Bai et al, Environmental Science and Policy,
2010)
Conceptual Framework4. Experiments and Transition
Findings from 30 Urban Sustainability
Practices in Asia
About half of all cases either multiplied or up-scaled tochange system of practice
Political aspect prominent for both success and failure,e.g. policy change as trigger, local government role asmain actor, state government support, institutionalaspect as major barrier
Technology or cultural aspect seldom identified as majorbarrier
Many international donor funded projects tend to stay asindividual experiment, some times multiplied but seldomup-scaled to change system of practice
4. Experiments and Transition
In Summary
Cities as human-dominant, complex, dynamic,evolving systems
Their internal and external dynamics notnecessarily well understood, e.g. urban-
agriculture interaction. Presents enormous challenges as well as
opportunities for sustainability
The need to focus more on the role ofsustainability practices and experiments
What happens in cities will, to a large extent,define human-environment interaction in
Anthropocene
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