MEGACITIES IN THE CONTEXT OF ECOLOGY · OF ECOLOGY. Excellence in science WWF Definition of...

Excellence in science

Human ecological footprintsHuman ecological footprintsPopulation growth, urban/rural shifts, Population growth, urban/rural shifts, and mega citiesand mega citiesEcological sustainability:Ecological sustainability:

-- climate changeclimate change-- diseasedisease-- food and waterfood and water

MEGACITIES IN THE CONTEXT MEGACITIES IN THE CONTEXT OF ECOLOGYOF ECOLOGY


WWF Definition of WWF Definition of ““Ecological FootprintEcological Footprint””

The biologically productive area to produce: The biologically productive area to produce: food and wood (cropland, grazing land, food and wood (cropland, grazing land, forest), room for infrastructure, absorb COforest), room for infrastructure, absorb CO22from burning fossil fuels from burning fossil fuels

[[BUTBUT omits: water consumption, release of omits: water consumption, release of pollutants.]pollutants.]


Paradoxes and Ethical Paradoxes and Ethical DilemmasDilemmas

2.182.182.852.85World AverageWorld Average

8.028.027.537.53SwedenSweden

0.640.641.701.70EgyptEgypt

biological capacity biological capacity per personper person

ecological footprint ecological footprint per personper person

CountryCountry


The Ecological Footprints of The Ecological Footprints of CitiesCities

Today, cities occupy roughly Today, cities occupy roughly 2%2% of of the Earththe Earth’’s land surface. BUT they s land surface. BUT they consume more than consume more than 75%75% of its of its resources.resources.


LONDONLONDONarea occupied: area occupied: ~1,500km~1,500km22

footprint (supplies and waste disposal): footprint (supplies and waste disposal): ~20 million km~20 million km22

London is home to 12% of UK population. London is home to 12% of UK population. BUT it uses the equivalent of BUT it uses the equivalent of ALLALL the UKthe UK’’s s productive land (of course, land used to productive land (of course, land used to supply its food extends globally).supply its food extends globally).


Human Population GrowthHuman Population GrowthHas not been simply exponentialHas not been simply exponential

Three phases of rapid change/growthThree phases of rapid change/growth““Agricultural RevolutionAgricultural Revolution””, beginning 10,000 years , beginning 10,000 years ago, slowed by rises of diseases in urban ago, slowed by rises of diseases in urban aggregationsaggregations““Scientific/Industrial RevolutionScientific/Industrial Revolution”” in the West, in the West, beginning ~ 1600beginning ~ 1600--17001700Spread of scienceSpread of science--based public health, twentieth based public health, twentieth centurycentury


Human NumbersHuman Numbers

TimeTime PopulationPopulation~1830 1 billion~1930 2 billion~1970 4 billion

today 6.3 billion2050 ~ 9 billion


UrbanUrban--Rural ShiftsRural Shifts

95% of the 95% of the ““buildoutbuildout”” of human numbers of human numbers will occur in the will occur in the urban areasurban areas of developing of developing countries (whose populations will double, countries (whose populations will double, to 4 billion, by 2050)to 4 billion, by 2050)


From arguably the first From arguably the first ““big citybig city””, Ur, in , Ur, in Sumeria, 4,000 years ago (~35,000 Sumeria, 4,000 years ago (~35,000 inhabitants), to Tokyo today (~26 inhabitants), to Tokyo today (~26 million), cities have consistently buried million), cities have consistently buried more people than they have given birth more people than they have given birth to.to.


The urban Fraction of Global PopulationThe urban Fraction of Global Population

TimeTime FractionFraction1700s1700s less than 10%less than 10%19001900 25%25%todaytoday 50%50%20502050 67%67%


The Rise of Big CitiesThe Rise of Big Cities

TimeTime Number of cities withNumber of cities withpopulations over 1 populations over 1

millionmillion

19501950 8686todaytoday 38638620152015 at least 550at least 550


TOP 12 MEGACITIES IN 2015?TOP 12 MEGACITIES IN 2015?

14.614.613.013.09.19.1Buenos AiresBuenos Aires16.216.211.111.14.04.0KarachiKarachi16.816.813.813.87.97.9CalcuttaCalcutta17.017.010.110.11.91.9LagosLagos17.517.512.312.34.84.8JakataJakata17.917.911.611.62.22.2DhakaDhaka19.719.718.318.315.915.9New YorkNew York20.020.017.817.89.69.6Sao PaoloSao Paolo20.620.618.718.710.710.7Mexico CityMexico City20.920.914.114.14.44.4DelhiDelhi22.622.617.417.47.37.3MumbaiMumbai36.236.235.035.026.626.6TokyoTokyo

Population (millions)Population (millions)19751975 20042004 2015 (estimated)2015 (estimated)

CityCity


By 2020, an estimated 23 cities By 2020, an estimated 23 cities (roughly half in Asia) will have (roughly half in Asia) will have passed the 10 million mark. passed the 10 million mark. Around 600 cities will have one Around 600 cities will have one million or more inhabitants.million or more inhabitants.


NOT ALL CITIES ARE MEGANOT ALL CITIES ARE MEGA

¾¾ of population growth will end up in of population growth will end up in ““secondsecond--tiertier”” cities cities (population less than 8 million)(population less than 8 million)In China, for example, officially In China, for example, officially 193193cities in 1978; cities in 1978; 640640 today.today.


SLUMS AND (SOME, NOT ALL) SLUMS AND (SOME, NOT ALL) MEGACITESMEGACITESIn the ninteenth and early twentieth century In the ninteenth and early twentieth century slums in Western cities, mortality rates were slums in Western cities, mortality rates were appalling.appalling.

With better understanding of infectious With better understanding of infectious disease (vaccination; dynamics of disease (vaccination; dynamics of transmission), this is not generally true transmission), this is not generally true today.today.


Infant mortality todayInfant mortality today

Annual total births:Annual total births: ~ 130 million~ 130 millionInfant deaths:Infant deaths: ~ 10 million~ 10 million


Another differenceAnother difference

Earlier slums resulted largely from Earlier slums resulted largely from industrialisation, drawing workers to industrialisation, drawing workers to cities (usually the centre), and tending cities (usually the centre), and tending to slow to slow –– or even reverse migration to or even reverse migration to countryside countryside –– as prosperity grew.as prosperity grew.


Today, in some places (e.g. China) the pressures Today, in some places (e.g. China) the pressures of industrialisation are similar. But in other of industrialisation are similar. But in other places (subplaces (sub--Saharan Africa, Latin America, Saharan Africa, Latin America, Middle East, parts of Asia) urbanisation is Middle East, parts of Asia) urbanisation is radically decoupled from industrialisation, and radically decoupled from industrialisation, and even from development as such. This even from development as such. This ““perverseperverse””urban boom contradicts orthodox economic urban boom contradicts orthodox economic models. So instead of being a focus for growth models. So instead of being a focus for growth and prosperity, some cities have become and prosperity, some cities have become dumping grounds for surplus populations, dumping grounds for surplus populations, working in unskilled and unprotected trades and working in unskilled and unprotected trades and informal services industries.informal services industries.


Arguably, the wellArguably, the well--intentioned I.M.F. intentioned I.M.F. structural Adjustment Programs have, structural Adjustment Programs have, over the past 20 years, increased urban over the past 20 years, increased urban poverty and slums, increased exclusion poverty and slums, increased exclusion and inequality, and weakend cities as and inequality, and weakend cities as engines to promote economic growth.engines to promote economic growth.


Three Worlds (2000)Three Worlds (2000)

3.13.11.71.71.61.6Fossil carbon Fossil carbon (billion metric tons (billion metric tons C per year)C per year)

6.36.30.20.2

3.23.20.20.2

2.92.91.41.4

Industrial energy (tw)Industrial energy (tw)Biomass energy (tw)Biomass energy (tw)

0.80.82323

1.21.21111

4.14.11111

Population (billions)Population (billions)GDP (trillion ppp$)GDP (trillion ppp$)

RichRichTransitioTransitionn

PoorPoor


““Bacterial and viral diseases are the price Bacterial and viral diseases are the price humanity has paid to live in large and humanity has paid to live in large and densely populated cities. Virtually all the densely populated cities. Virtually all the familiar infectious diseases have evolved familiar infectious diseases have evolved only since the advent of agriculture, only since the advent of agriculture, permanent settlement and the growth of permanent settlement and the growth of cities.cities.


Most were transferred to humans from Most were transferred to humans from animals animals –– especially domestic animals. especially domestic animals. Measles, for instance, is akin to rinderMeasles, for instance, is akin to rinder--pest in cattle; influenza came from pigs; pest in cattle; influenza came from pigs; smallpox is related to cowpox. Humans smallpox is related to cowpox. Humans share 296 diseseases with domestic share 296 diseseases with domestic animals.animals.””

From John Reader, the author of From John Reader, the author of CitiesCities(Heinemann, 2004)(Heinemann, 2004)


More recently:More recently:

HIV/AIDS came from bushmeat trade HIV/AIDS came from bushmeat trade (HIV(HIV--I, chimps; HIVI, chimps; HIV--2, monkeys)2, monkeys)

SARS from internationalisation of SARS from internationalisation of bushmeat trade (civets)bushmeat trade (civets)


““The time has come to close the book The time has come to close the book on infectious diseaseson infectious diseases””

W.H.StewartW.H.StewartU.S. Surgeon General, 1967U.S. Surgeon General, 1967


The Green Revolution, The Green Revolution, caca. 1965. 1965--20002000

Food productionFood production x 2 x 2 (up 100%)(up 100%)Extra land usedExtra land used x 1.1x 1.1 (up (up 10%)10%)Global populationGlobal population x 1.6 (up x 1.6 (up 60%)60%)Nitrogen fertilizerNitrogen fertilizer x 7 (up 600%)x 7 (up 600%)


Could not feed todayCould not feed today’’s population with s population with yesterdayyesterday’’s agricultures agricultureBUT, signs of plateau. Need BUT, signs of plateau. Need ““Doubly Doubly Green RevolutionGreen Revolution””(More production, More environmentally (More production, More environmentally friendly)friendly)


Supplies of waterSupplies of water

Global patterns of useGlobal patterns of use10%10% domesticdomestic21%21% industrialindustrial69% 69% agricultureagriculture


TodayToday:: 29 countries, with 0.5bn 29 countries, with 0.5bn people, are in people, are in ““water water deficitdeficit””

By 2020By 2020: 50 countries, with 3 bn : 50 countries, with 3 bn people, will be in people, will be in ““water water deficitdeficit””


Human ecological footprintsHuman ecological footprintsPopulation growth, urban/rural shifts, Population growth, urban/rural shifts, and mega citiesand mega citiesEcological sustainability:Ecological sustainability:

-- climate changeclimate change-- diseasedisease-- food and waterfood and water

MEGACITIES IN THE CONTEXT MEGACITIES IN THE CONTEXT OF ECOLOGYOF ECOLOGY

MEGACITIES IN THE CONTEXT OF ECOLOGY · OF ECOLOGY. Excellence in science WWF Definition of...

Documents

Transcript of MEGACITIES IN THE CONTEXT OF ECOLOGY · OF ECOLOGY. Excellence in science WWF Definition of...