image/svg+xml
Hungrycitiesinachangingclimate
Thequestforasustainablefoodsupply
SteffenKriewald
,PrajalPradhan,LuisCosta,
DiegoRybski&JürgenP.Kropp
September21,2017
Neuf-Brisach
GFDL, Norbert Blau
Western
0.08
0.26
0.43
0.6
0.77
Northern
America
Central
America
Caribbean
South
America
Northern
Africa
Western
Africa
Middle
Africa
Eastern
Africa
Southern
Africa
AUS
&
NZL
South
−
Eastern
Asia
Southern
Asia
Eastern
Asia
Central
Asia
Asia
Eastern
Europe
Southern
Europe
Northern
Europe
Western
Europe
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Demographic growth 2050
Climate change RCP 8.5 2050
Diet change 2050
Base scenario
0.49
0.63
0.77
0.91
1.04
Northern
America
Central
America
Caribbean
South
America
Northern
Africa
Western
Africa
Middle
Africa
Eastern
Africa
Southern
Africa
AUS
&
NZL
South
−
Eastern
Asia
Southern
Asia
Eastern
Asia
Central
Asia
Western
Asia
Eastern
Europe
Southern
Europe
Northern
Europe
Western
Europe
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- Cities are cores of economic activities and cultural development
- Hotspots of consumption & waste production, attracting resources from its hinterland
- How can the exchange of material between urban system and its hinterland be optimized?
•
Incomegenerationindevelopingcountries
•
Foodsecurity(availability)
•
Urbannutrientcycles
•
Fromagriculturedecoupledurbanpopulation
•
Increasingtransportcosts
•
Mitigation:reductionof
CO
2
fromtransport
•
But, only single case studies exist
Global model analyses the environmental gross effects of peri-urban food production:
- How much urban dwellers can be nourished by peri-urban food production?
- How will this change in the future due to urban growth, diets and climate change?
- How much CO
2
emissions can be saved by an optimized food transport?
0.00.10.20.30.40.5
foodshed size [km²]
Density
20010005000500005e+055e+06
1e-01
1e+01
1e+03
1e+05
1e+07
Urban Cluster
Total Emissions (tonne Co2/yr)
Optimum
Random
Random Sorting
Optimalyield
•
potential
kcal
/
m
2
forsevenFAOfoodgroups
•
considernationaldietarypattern
Findtheoptimumyieldon
n
cellsfor
m
foods:linearprogramming
x
=(
x
1
,...,
x
m
)
,
A
=(
A
1
,...,
A
m
)
with
x
i
=(
x
1
,
i
,...,
x
n
,
i
)
,
A
i
=(
a
i
,
1
,...,
a
i
,
m
)
forall
i
=
1
,...,
n
x
j
,
i
meansthepercentoffood
j
producedoncell
i
a
i
,
j
meansthefactorofproductionoffood
j
producedoncell
i
m
j
=
1
x
j
,
i
≤
1
∀
i
=
1
,...,
n
p
j
·
A
·
x
≤
A
j
·
x
j
∀
j
=
1
,...,
m
⇔
(
p
j
·
A
−
A
j
)
·
x
≤
0
∀
j
=
1
,...,
m
How to define a City?
Automated and consistent city identification with
Othodromic Spatial Clustering
based on City Cluster Algorithm (Rozenfeld et al. 2008)
How to define the urban hinterland?
literature: food transport 2010 = 0.7 GT (0.35 GT for urban)
- randomized 1.29 GT
- optimized 0.15 GT
Emissions from food transport can be halved,
which are 7-8% of all transport emissions
Conclusion:
- Peri-urban agriculture can nourish up to 30% of urban dwellers (1.1bn)
- Future (2050) change reduce this number to 20% (1.3bn)
- Food transport is unavoidable, but emissions can be reduced by 50%
Contact: kriewald@pik-potsdam.de
www.pik-potsdam.de/~kriewald/
Population
1e+06
5e+06
1e+07
Peri-urban Agriculture
Kriewald
Hungrycitiesinachangingclimate-Thequestforasustainablefoodsupply
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Bernau
Falkensee
Ludwigsfelde
Neuenhagen
Oranienburg
Strausberg
Bernau
Falkensee
Hennigsdorf
Ludwigsfelde
Neuenhagen
Oranienburg
Strausberg
Bernau
Falkensee
Ludwigsfelde
Neuenhagen
Oranienburg
Strausberg
Bernau
Falkensee
Ludwigsfelde
Neuenhagen
Oranienburg
Strausberg
Bernau
Falkensee
Ludwigsfelde
Neuenhagen
Oranienburg
Strausberg
Bernau
Falkensee
Ludwigsfelde
Neuenhagen
Oranienburg
Strausberg
Bernau
Falkensee
Ludwigsfelde
Neuenhagen
Oranienburg
Strausberg
Bernau
Falkensee
Ludwigsfelde
Neuenhagen
Oranienburg
Strausberg
Berlin
Berlin
Berlin
Berlin
Berlin
Berlin
Berlin
Berlin
Berlin
Bernau
Falkensee
Hennigsdorf
Hennigsdorf
Hennigsdorf
Hennigsdorf
Hennigsdorf
Hennigsdorf
Hennigsdorf
Hennigsdorf
Hohen Neuendorf
Hohen Neuendorf
Hohen Neuendorf
Hohen Neuendorf
Hohen Neuendorf
Hohen Neuendorf
Hohen Neuendorf
Hohen Neuendorf
Hohen Neuendorf
Kleinmachnow
Kleinmachnow
Kleinmachnow
Kleinmachnow
Kleinmachnow
Kleinmachnow
Kleinmachnow
Kleinmachnow
Kleinmachnow
Ludwigsfelde
Neuenhagen
Oranienburg
●
Potsdam
Potsdam
Potsdam
Potsdam
Potsdam
Potsdam
Potsdam
Potsdam
Potsdam
Strausberg
Teltow
Teltow
Teltow
Teltow
Teltow
Teltow
Teltow
Teltow
Teltow
Potential yield for seven
food groups + animal products
arranged for national diets
- over 4000 urban clusters with more than 100.000 people
- 2.536 bn or 71% of global urban population
- 2.15 bn km² or 8.5% of global arable land
- in average: 63% of hinterland is used for agricultural purpose
argriculture
bare
natural
2010: 933m - 26.1% of global urban pop
00
25
50
75
100 %
Self-sufficiency
Optimized 2010: 1073m - 30.1% of global urban pop
00
25
50
75
100 %
Self-sufficiency
Optimized 2050 RCP
8.5
: 1287m - 20.3% of global urban pop
00
25
50
75
100 %
Self-sufficiency
-1.0
-0.5
0.0
0.5
1.0
Change
climate
food
growth
Distance food transported (km)
10
50
100
500
1000
5000
1
title
cities
pua
pua-r
model
definition
past
today
urban
border
osc
osc1
osc2
osc3
osc4
cluster
cluster-n
hinterland
hinterland1
hinterland2
opti
world
buffer
cc
cc_max
cc_max_2050
cc_change
mi
food
climate
urban
foodm
foodm2
foodm3
final