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16/11/2017
1
De bevolkingsexplosie: probleem of kans ?
Gerard Govers
KU Leuven
Het probleem
• HUMO Een verdubbeling van de bevolking om de veertig jaar: kan je die cijfers extrapoleren naar de hele wereld?
‘Vermeersch «Nee, want op wereldvlak is het nog erger gesteld. We zitten nu aan bijna zeven miljard mensen. Maar als iedereen blijft denken dat hij of zij recht heeft op vier kinderen, verdubbelt de bevolking met elke generatie. Als we gewoon blijven voortgaan zoals nu, zitten we over zes, zeven generaties met 1000 miljard mensen op aarde. Dat is te veel, dat snapt elke kleuter. (schudt het hoofd) Natuurlijk zullen we nooit aan 1000 miljard raken. Want vooraleer het zover komt zal de aarde getroffen worden door verschrikkelijke hongersnoden, epidemieën en oorlogen. De plunderingen in Haïti: dat wordt de realiteit van alledag. De genocide in Rwanda ‐ toch een van de gruwelijkste oorlogen die we de laatste jaren hebben gekend ‐ was het gevolg van overbevolking. Waarom hebben die mensen mekaar uitgemoord? Uit plaatsgebrek, natuurlijk. ‘
Others are worried too
June 2017
But some of those have bad timing…
We moeten de bevolkingsgroei stoppen….
• Er zijn steeds meer kinderen (vooral in arme landen)
• Die gaan ook weer meer kinderen hebben !
• Etc….
Dit leidt tot een ongecontroleerde bevolkingsexplosie !
16/11/2017
2
But not everyone agrees:
• https://www.youtube.com/watch?v=KbwNgI_gFMI
• https://youtu.be/vZVOU5bfHrM
So, we need to consider in more detail what is going on ?
• Is the world population spinning out of control ?
• What controls population growth ?
• What can be done to limit it ?
Planning should be knowledge based
• So, how good is our knowledge ?
• What do we know ?
Let us take a simple quiz
• Questions will appear at: www.pollev.com/gerardgovers076
The quiz is a modified version of the on developed by Hans Rösling:http://edition.cnn.com/2013/12/10/world/gapminder‐us‐ignorance‐survey/
16/11/2017
3
16/11/2017
4
So, it appears we can use an update
• This lecture will cover the basics of global population dynamics
• The material is essentially non‐mathematical
But let us start with some math: exponential growith
Exponential growth
rNdt
dN
N= size of populationt= timer=per capita growth rate per capita, also difference between birth rate, b, en death rate, d, so r=b‐d
16/11/2017
5
Integration results in:
rtc
crtN
eeN
ee
crtN
crtcN
rdtN
dN
ln
ln
21ln
We can solve for e0 by setting the time to 0:
c
rc
eN
eeN
0
00
rteNN 0
So that we can write :
rtNNt 0lnlnOr:
This may look very unfamiliar to you but your bank is using it all the time
This is what your bank does when it calculateshow your capital ‘grows’ due to interest:
Nt+1=Nt(1+r)
r=fractional growth rate
Or: each year we add an amount of interest to the capital which we calculate as a fraction of that capital (e.g. 2%)
Graphically: evolution of cell phoneusers in USA (thousands)
Most important properties
• Exponential growth accelerates over time because a fraction of what is already there is being added every year
• Exponential growth does not have any limit: the capital/population can exceed any fixed threshold if there is a sufficient amount of time
16/11/2017
6
This is the model that Etienne Vermeersch implicitly uses
• Each family has more than two children
• These children will also have more than two children…
• Etc., etc., ../…
Does he (and others, like Ehrlich) have a point ?
Exponential growth results on a linearrelationship between N and time on a
semilog paper
0
500000
1000000
1500000
2000000
2500000
3000000
3500000
4000000
4500000
5000000
0 2 4 6 8 10 12 14 16
Growth of mobile phone usage
1
10
100
1000
10000
100000
1000000
10000000
0 2 4 6 8 10 12 14 16
Growth of mobile phone usage
Bevolkingsgroei op Aarde
0,00E+00
1,00E+09
2,00E+09
3,00E+09
4,00E+09
5,00E+09
6,00E+09
7,00E+09
0 500 1000 1500 2000 2500
Population
Year (AD)
Evolution of population
World population
Asia
Western Europe
Western offshoots
Africa
Is dit exponentiële groei ? Groei is dus sneller dan exponentieel
1,00E+05
1,00E+06
1,00E+07
1,00E+08
1,00E+09
1,00E+10
0 500 1000 1500 2000 2500
Population (log axis)
Year (AD)
Evolution of Population
World population
Asia
Western Europe
Western offshoots
Africa
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7
Groei is super‐exponentieel
• Is een proces dat niet kan blijven duren omdat hulpbronnen uitgeput geraken
• Bevolkingsgroei is nu 1% per jaar: reken even uit wat de bevolking van de Aarde zal zijn in 2117 ?
Answer:
• Ca. 20 billion !
Vraag: zal het blijven duren tot het systeem Aarde in elkaar stort ?
• Om die vraag te kunnen beantwoorden:
– Analyse van bevolkingsgroei in het verleden
– Deze analyse gebruiken om een zo goed mogelijke voorspelling te doen
Population evolution varies widely
0
20000
40000
60000
80000
100000
120000
140000
1650 1700 1750 1800 1850 1900 1950 2000 2050
japan
ethiopia
germany
A relative graph is clearer (1910=100)
0
100
200
300
400
500
600
700
800
900
1800 1850 1900 1950 2000 2050
japan
ethiopia
germany
world
So what is going on here ?
1,00E+05
1,00E+06
1,00E+07
1,00E+08
1,00E+09
1,00E+10
0 500 1000 1500 2000 2500
Population (log axis)
Year (AD)
Evolution of Population
World population
Asia
Western Europe
Western offshoots
Africa
Industrial Revolution
16/11/2017
8
The curves show a rapid increase from ca. 1750‐1800
• What happened in that period ?
Industrial revolution
Industrial Revolution
• Official start: invention of steam engine by James Watt (1762)
• Was a further development of existing engines (Newcomen engine, 1712)
• Dramatic change of working conditions
– Emergence of factories&mines where people worked in dreadful conditions
So, not really a happy time
Question: did the Industrial Revolution lead to an increase or a decrease in
mortality ?
John Constable, The Haywain, 1821
The answer is somewhat surprising
16/11/2017
9
The answer is somewhat surprising: mortality declined right from the beginning of the IR
Oded, 2012
From the start of the 18th century in England/Wales, somewhat later in other European countries, but serious decline starts after 1780 in all Western European countries
Why is this ?• Basic change : use of fossil fuels to producemechanical energy
– Total annual useful energy production of a grown man: 0.075*10*300= ca. 225 kWh per year or225*1000*3600=810Mj (1 kWh=1000*3600 Ws=3.6Mj), orca. 2 MJ per day
– 1 kg of wood: 15 MJ
– 1 kg of glucose : 20 MJ
– 1 kg of coal: 30 MJ
– 1 kg of diesel: 50 MJ
– 1 kg of hydrogen: ca. 143 MJ
– 1 Kg of Li‐ion battery: 0.72 MJ
– 1 kg of Uranium: 79.5E6 MJ
To put this in perspective
• The physical labour that a healthy human male can perform in one year is energetically equivalent to ca. 16 liters of diesel
=
1 full year of this:
The energy needed to heat a house in Belgium is equivalent to the physical work of 100 people
=
A very nice illustration: https://www.youtube.com/watch?v=C93cL_zDVIM Industrial revolution=development on
speed due to increased energy availability
16/11/2017
10
Industrialisation causes a chainreaction of changes leading to a
FUNDAMENTALLY different society
Energy
Workers
Socialism
Training
Health care
Reducedreligiousinfluenc
e
Capital
Migration
Urbanisation
State organisation
AgricultureScie
ncenutrition
Would you train these workers: yes or no ?
If people get training
• They will work better, so you will make more profit
• You will have to replace less people
• They will be better able to adjust to changes
But also…
• They will be better able to follow a medical treatment
• They will better understand what makes them ill (and avoid it)
• They will become better at expressing their needs and requesting change…
Changes led to a dramatic reduction in mortality
• Better information
• Better medication
• Better food
• Better government institutions
• Diminishing influence of religion
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One example…. What explains the mortality decline ? • Health
– Improved health care– Improved medicins
• Vaccinations: from ca. 1785 Antibiotics: from 1928 (Fleming)
– Sanitation• John Snow 1854: link betweencholera and trinking water
• Improved food provision• Food sterilisation (1810)• Improved yields (Fertilisation, von Liebig (1840))
What explains the mortality decline ?
• Level of development and education
– Hygiene
– Therapy adherence
• Governmental action
– Sanitation: sewage disposal, garbage removal, planning
– Establishment of medical‐social care systems
First vaccinations
• Smallpox killed 8 to 20% of all people in the 18th century
• Inoculation (scarring) with scabs (korstjes) of people having smallpox (pokken) reached Europearound ca. 1724 (Lady Montagu (writer and Turkish Ambassador of the UK) authorised the inoculation of her son by the Embassy surgeon in 1716. Scientific description in 1724. Jenner developed a (safe) vaccine from cowpox afternoting that milkmaids did not get smallpox in 1796.
John Snow• Discovered that there was a geographical connectionbetween cholera outbreaks and location of water pumps/wells
Mortality could be greatly reduced by simply shutting off infected pumps
Gains were *very* important
16/11/2017
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Level of development and education
Galor, 2012
Government action: water quality
• Generally important improvement over the last decade• is in fact in many cases 2nd
wave of improvement• first wave due to bettertreatment of mainlyhousehold water• second wave related to better treatment of household+industrial waste with modern techniques (taking care of chemical pollution as well)
Important
• This progress is not directly coupled to economic growth (wealth), but rather to improved societal conditions/better science/better technology
• Changes driven by same processes that lead to economic growth but there is no direct, causal link between income level and mortality level: it has more to do with how society works (think Cuba)
• Clearly, increase in available income made progress possible (think of sewer systems)
The transition started (much) later in other countries
• Decline of mortality starts when countries get integrated in global, industrial, capitalist system
• In Europe of the 19th century this happenedwhen the industrial revolution reached a country
It took about 50 years to reach E Europe
Oded, 2012
From the start of the 18th century in England/Wales, somewhat later in other European countries, but serious decline starts after 1780 in all Western European countries
But also in these other countries mortality declined right from the start
16/11/2017
13
Timing
• Engeland: 2de helft 18de eeuw
• West‐Europa en N‐Amerika: 1ste helft 19de
eeuw
• Rusland and Zuid‐Europa: eind 19de‐begin 20ste eeuw
• Azië: na WO I
• Afrika: na WO II
What do you expect ?
• Will decline of mortality go slower or faster in Africa/India in comparison to England ?
• Why ?
Timing is crucial: mortality declinedfaster when decline started later
Na daling sterfte volgt de dalingvruchtbaarheid
• Volgt altijd na daling sterfte
Fertility declined in Europe, similarly to mortality, but later
Decline of fertility started in most countries after 1860Oded, 2012
Daling van de vruchtbaarheid
• Begint het eerste in Frankrijk, voor begin 19de
eeuw: effect van Franse revolutie
• Andere landen van West‐Europa en Noord‐Amerika: vanaf einde 19de eeuw (Engeland eerst)
• Zuid‐Europa, Rusland, Argentinië: begin 20ste
eeuw
• Azië: na WO II
• Sub‐Saharisch Afrika: na 1990
16/11/2017
14
Waarom daalt vruchtbaarheid ?
• Subvraag 1: waarom was de vruchtbaarheid zo hoog ?
• Subvraag 2: waarom daalt ze ?
Hoeveel kinderen zou je later willen ?
• https://pollev.com/gerardgovers076
Veronderstel nu even dat je in het 16de eeuwse Engeland leeft
• De kindersterfte is er erg hoog (tot 40%)
• Kinderen in eenlandbouwmaatschappij=levensverzekering– Zorgen voor kernfamilie (ouders, ook andereverwanten)
– Onderhouden van familiekapitaal (landbouwland, huis)
– Verklaart ook belang dat aan familie, erfrecht envoortplanting wordt gehecht in dit soortsamenlevingen
Welke kans zou je willen accepteren om in ditsoort samenleving minder dan twee kinderen
over te houden ?
• https://pollev.com/gerardgovers076
16/11/2017
15
We can use these statistics to gain some insight
• Binomial distribution:
– Finite number of trials (n)
– Outcome of each trial determined by a priori probability (p)
– You can then calculate the number of successes (k)
Properties of binomial distribution
)!(!
!
)1(
);;(
)1(][
][
knk
n
k
n
ppk
n
ptoequalissuccess
ofprobwhentrialsnwithsuccesseskofyprobabilitpnkp
pnpXVar
npXE
knk
k
• You can now plot cumulative probabilities:
– Calculate each invidual
– Sum them for all values up to the value of k you want to consider, for a given value of n
max
1
k
kkp
);;( pnkpk
How does that look ?
0
0,2
0,4
0,6
0,8
1
1,2
0 1 2 3 4 5 6 7 8 9
cumulative probaility of survival
Number of children (or less) that survive
1
2
3
4
5
6
7
8
children born
There is ca. 20% chance that 2 children or less will survive if you have 6 children
Even if you have 5 children, there is a 9% change thatyou will end up with max. one survivor
Conclusion
• In order to be 90% sure that two children will survive when the child mortality=40%, you will need to have no less than 7 children
Total fertility rate in Niger
www.gapminder.org
16/11/2017
16
However:
• The average number of children surviving will be much larger than two: consequence of the insurance principle
• 7 children born will lead to (on average) 4,2 children that survive
So, what do we need to do to get fertility in Niger down ?
We need to reduce child mortality
“ If we want to reduce population growth we need to make sure that more children survive”
Child mortality
https://goo.gl/oaylGG
Yes, but don’t you need anticonception to decrease fertility ?
Not really : look at the Belgians
www.gapminder.org
16/11/2017
17
Other factors are also important Marriage age
• Age at 1st marriage
General development
• Human Development Index
Income
• Income (PPP and inflation‐corrected)
Education (women 25‐34 y)
• Education
Urbanisation (and schooling)
UN, 2008
16/11/2017
18
What about government policies ?
• Family planning counseling
• Abortion
• Sterilisation
Politics: China vs. India
1966‐1976 Cultural
Revolution
1958‐1962 Big Leap ahead
1979 One childpolicy
1952 Family planning program
1976 National Population
plan
Later‐longer‐fewer policy
Government policies
• Coercion rarely helps: in most societies, people consider family planning a private matter and experience government coercion as totally unacceptable
• Supportive actions are another matter: policies may help to reduce birth rates faster as the desire to have less children often precedes the facts
!
Samenvatting beïnvloedende factorenIndicator Groepen landen Daling van het totale
vruchtbaarheidscijfer
68-75 (promille)
I II III I II III
BNP/inwoner >500$ 250-500$ <250$ 630 354 302
% verstedelijking > 50 25-50 < 25 743 521 329
Kindersterfte >13,0 5,0-13,0 5,0% 238 456 783
Levensverwachting > 65j 50-65j < 50j 871 608 255
% vrouwen in de landbouw > 50 25-50 < 25 332 505 635
% geletterden > 50 25-50 < 25 716 404 232
% schoollopende mannen (°) > 50 25-50 < 25 583 424 141
%schoollopende vrouwen > 50 25-50 < 25 717 848 249
Inspanningen op gebied vangeboortebeperking
sterk matig geenzwak
1157 962 214
Snelheid van daling vruchbaarheid
16/11/2017
19
England‐Wales vs. France
16 °/°° in 50 yrOr 0.32 °/°° yr‐1
England‐Wales vs. France
18 °/°° in 160 yrsOr 0.11 °/°° yr‐1
20 °/°° in 45 yrOr 0.44 °/°° yr‐1
25 °/°° in 60 yrsOr 0.42 °/°° yr‐1
The rest of the world mainly followed the Anglo‐Saxon model
Geboortecijfers dalen gemiddeld niet (veel) sneller in landen waar transitie
later begint: waarom niet ?
Geboortedaling is een cultureel proces
• There are now ca. 800 traffic deaths per yearin Belgium
• How many traffic deaths were there in 1970 ?
Pollev.com/gerardgovers076
Evolutie verkeersdoden in België
http://www.steunpuntverkeersveiligheid.be/sites/default/files/RA‐MOW‐2009‐013.pdf
Aantal voertuigen 1977: 3.3 miljoenAantal voertuigen 2011: 6.8 miljoen(http://statbel.fgov.be/nl/binaries/2012_Brochure%20mobilit%C3%A9%20A4%20NL%20web_tcm325‐157822.pdf)
Snelheidsbeperkingen: vanaf 1973 (oliecrisis, niet verkeersveiligheid, gordelplicht vanaf 1975)
16/11/2017
20
Die daling kan je niet alleen toeschrijven aan betere medische zorg
We zijn er nog niet
Dus
• Geboortedaling is voor een groot gedeelte een socio‐cultureel proces.
• De transitie vereist dus dat er belangrijke socio‐culturele veranderingen plaatsvinden.
• De sterftedaling is, in tegenstelling hiermee, vooral bepaald door wetenschappelijk‐technische ontwikkelingen
What would you expect to happen to fertility if
• Child mortality decreases slowly due to the gradual introduction of new technology, better health care better food ?
• Child mortality decreases rapidly due to the rapid introduction of all these things ?
Let us see:
https://goo.gl/SCBaIn
We hebben dus een basismodel: de demografische transitie
16/11/2017
21
Basic model
http://www.globalchange.umich.edu/globalchange2/current/lectures/human_pop/human_pop.html Reher, 1994: four types of transition
But with regional variations
What does this imply for population growth
• Developed countries: – birth and death rates already somewhat reduced before the start of IR
– Slow decline of mortality
– Slow decline of fertility
• Developing countries– Birth and death rates very high at start of IR
– Sudden decline of mortality
– Slow decline of fertility
time
Crudemortalityand fertilityrates
The developed world
time
Crudemortalityand fertilityrates
The developing world Thus, the increase in population is not everywhere the same dueto demographic transition: much higher in the South
50
500
‐150 ‐100 ‐50 0 50 100 150 200 250 300
japan
ethiopia
germany
ecuador
16/11/2017
22
Question
• Could there be another phase following onphase 4 ?
Let us have a look at Japan: the past…
The near future And the not so near future
Laten we eens even nadenken wat dit betekent voor de groei van de wereldbevolking
• Gaat die blijven groeien ?
• Gaat de groeisnelheid contant blijven ?
Dus….
• Bevolkingsexplosie is gevolg van demografische transitie
• Is een tijdelijk fenomeen
• We zitten nu in de eindfase
16/11/2017
23
Gross fertility 2005‐2010
http://upload.wikimedia.org/wikipedia/commons/7/78/Fertility_rate_world_map_2.png
Is the next statement true ?
We need birth control to stop overpopulation because…
• There are ever more children (especially in poor countries)
• They will again have more children !
• Etc….
Neen
http://www.census.gov/ipc/www/idb/worldgrgraph.html
In somewhat more detail: Globally, remaining growth is about
filling up the pyramid
• What do we mean by that ?
16/11/2017
24
Well…the number of children on the planet is already over the top
UNDP World population prospects 2010
595 000
600 000
605 000
610 000
615 000
620 000
625 000
630 000
635 000
640 000
645 000
650 000
2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100 2110
UNDP prediction of number of children < 5yr
kind < 5
UNDP, World Population prospects data 2010
Verdere groei van de wereldbevolking
• Niet meer te wijten aan stijgend kinderaantal
• Volledig te wijten aan verhoging van de levensverwachting
How far will aging go ?
Life expectation continues to rise… And there are optimists…
16/11/2017
25
But there is a catchAge of oldest person in the world at
death vs time
108
110
112
114
116
118
120
122
124
24/jan/41 3/okt/54 11/jun/68 18/feb/82 28/okt/95 6/jul/09 15/mrt/23
Series1
Data from wikipedia
Maximum age of survivors moves hardly, but much more people live up to a ‘decent’ age
https://www.env.go.jp/en/wpaper/1995/eae240000000000.html
Despite this optimism we need to be careful
• We cannot do anything but rejoice about the fact that almost everybody in the world now lives to a decent age (and we do not want to do anything about that)
• Thus: only possible control on population growth is through control of fertility
Hoe zorgen we voor controle op groei?
• Niet door te panikeren
• Niet door stringente geboorteprogramma’s
• Wel door verder terugdringen kindersterfte
• Wel door verschaffen onderwijs, vooral aanjonge vrouwen
Fertility decline is difficult to predict
Gerland et al., 2013, Science
16/11/2017
26
And slight varitions in TFR have a strong impact on total population
Gerland et al., Science, 2013
Recently, projections for Africa have been revised upward: perhaps 4 billion Africans
in 2100
Gerland et al., 2013, Science
But we do now that some factors have a tremendous effect on TFR
• Child mortality
• Education
Mortality decline
(Child) mortality has declined to near‐minimum levels in mlany countries over the last 25 years
Mortality decline
(Child) mortality has also declined in Africa, but will decline further, less room for decline in other regions
Besides child mortality education (of women) is of tremendous importance
16/11/2017
27
Key factor is education (Lutz et al., 2011)GET: globaleducationtrendCER: constant enrrollmentrateCEN: constant enrollmentnumbersFT: fast track (Singapore and S‐Korea
Comparing different SSP’s
Lutz et al., 2014SSP=shared socio‐economic pathway
For each SSP
• Try to predict effects on life expectancy and TFR using known effects of :
– Education
– Wealth
– Etc….
Results show that very different developments are possible
This is also true for individual countries
16/11/2017
28
Main lesson
• There is nothing inevitable about uncontrolled population growth
• It all depends on our actions as a global community
• If we invest in schooling and medical aid
Is bevolkingsexplosie een kans ?
Waar is het aantal actieven het grootst t.o.v. het aantal ouderen en jongeren ?
UNDP World population prospects 2010
Bloom and Canning, 2004
Wat betekent dat voor economische groei ?
An and Jeon, 2006
Demography also explains withincountry variations in growth
Growth rate between 2000 and 2010 of different states in the US vs growth rate in 60+ population over same period (Maestas et al., 2016
16/11/2017
29
Afrika is een groeicontinent En dit krijgen we in Japan….
But make no mistake:
• It is not the number of people that counts
• It is how they are skilled. It is not the duration of schooling but the level achieved that is important
Conclusies
• Bevolkingsexplosie is soms problematisch
• Maar : er komt een einde aan
• Het komt erop aan om ervoor te zorgen dat ontwikkelingslanden kunnen profiteren van de kansen die de demografische transitie biedt op economische ontwikkeling
• Hoe doen we dat ? Investeer in onderwijs en vooral in kwaliteitsvol onderwijs
Conclusie
• Volwassen samenlevingen hebben het omgekeerde probleem: vergrijzing verhindert economische groei
• Get used to it !
• But remember: ‘Prediction is very difficult, especially when it is about the future’ (N. Bohr)
16/11/2017
30
www.gapminder.org
• Website with lots of data
• Allows us to visualise evolutions
But watch out for surprises
• “Prediction is very difficult, especially if it's about the future”, (N. Bohr)
What would you think would be the effect of the Fukushima disaster ?
http://media.npr.org/assets/img/2011/04/12/japan‐quake‐nuclear‐disaster‐accident‐files_6929693_custom‐365fa520bb48c84bd64f8f48d69e9a4f6e8f35ec‐s51.jpg
Oops !
http://www.indexmundi.com/g/g.aspx?v=31&c=ja&l=en
Hoe is die transitie tot stand gekomen ?
Industrial revolution played a key role
16/11/2017
31
Why industrialisation ?• Basic change : use of fossil fuels to producemechanical energy
– Total annual useful energy production of a grown man: 0.075*10*300= ca. 225 kWh per year or225*1000*3600=810Mj (1 kWh=1000*3600 Ws=3.6Mj), orca. 2 MJ per day
– 1 kg of wood: 15 MJ
– 1 kg of glucose : 20 MJ
– 1 kg of coal: 30 MJ
– 1 kg of diesel: 50 MJ
– 1 kg of hydrogen: ca. 143 MJ
– 1 Kg of Li‐ion battery: 0.72 MJ
– 1 kg of Uranium: 79.5E6 MJ
Industrialisation causes a chainreaction of changes leading to a
FUNDAMENTALLY different society
Energy
Workers
Socialism
Training
Health care
Reducedreligiousinfluenc
e
Capital
Migration
Urbanisation
State organisation
AgricultureScie
ncenutrition
What hebben we geleerd ?
• We hebben dikwijls weinig kennis van eenprobleem
• Weten=meten: opinies en beslissingen nemenop basis van feiten is een geode zaak
Jamaar, is er dan een probleem ? De vruchtbaarheid van de wereldbevolking is sterk gedaald (nu nog 2.44 kinderen/vrouw)
16/11/2017
32
Waarom ? Kindersterfte daalt Waarom daalt kindersterfte ?
• Verbetering medische zorg
– Betere technieken
– Goedkoperen technieken
• Maar ook…..
A summary…Het aantal jonge kinderen stijgt dan
ook niet meer
595 000
600 000
605 000
610 000
615 000
620 000
625 000
630 000
635 000
640 000
645 000
650 000
2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100 2110
UNDP prediction of number of children
kind < 5
UNDP, World Population prospects data 2010
Groei van de wereldbevolking
• Die is er vooral omdat we met zijn allen ouderworden….
16/11/2017
33
Well…the number of children on the planet is already over the top
UNDP World population prospects 2010
En wie kan daar nu tegen zijn ?