image/svg+xmlHungrycitiesinachangingclimate Thequestforasustainablefoodsupply SteffenKriewald ,PrajalPradhan,LuisCosta,DiegoRybski&JürgenP.KroppSeptember21,2017 Neuf-Brisach GFDL, Norbert Blau Western 0.08 0.26 0.43 0.6 0.77 NorthernAmericaCentralAmericaCaribbeanSouthAmericaNorthernAfricaWesternAfricaMiddleAfricaEasternAfricaSouthernAfricaAUS&NZLSouth − EasternAsiaSouthernAsiaEasternAsiaCentralAsiaAsiaEasternEuropeSouthernEuropeNorthernEuropeWesternEurope ●●●●●●●●●●●●●●●●●●● ● Demographic growth 2050Climate change RCP 8.5 2050Diet change 2050Base scenario 0.49 0.63 0.77 0.91 1.04 NorthernAmericaCentralAmericaCaribbeanSouthAmericaNorthernAfricaWesternAfricaMiddleAfricaEasternAfricaSouthernAfricaAUS&NZLSouth − EasternAsiaSouthernAsiaEasternAsiaCentralAsiaWesternAsiaEasternEuropeSouthernEuropeNorthernEuropeWesternEurope ●●●●●●●●●●●●●●●●●●● - 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 CO2 emissions can be saved by an optimized food transport? 0.00.10.20.30.40.5 foodshed size [km²] Density 20010005000500005e+055e+06 1e-011e+011e+031e+051e+07 Urban Cluster Total Emissions (tonne Co2/yr) OptimumRandomRandom 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 ,..., nx j , i meansthepercentoffood j producedoncell ia i , j meansthefactorofproductionoffood j producedoncell i m j = 1 x j , i ≤ 1 ∀ i = 1 ,..., np 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 ● ● ● ● ● ● ● ● ● ● ● 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 sevenfood groups + animal productsarranged 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 RCP8.5: 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
  1. title
  2. cities
  3. pua
  4. pua-r
  5. model
  6. definition
  7. past
  8. today
  9. urban
  10. border
  11. osc
  12. osc1
  13. osc2
  14. osc3
  15. osc4
  16. cluster
  17. cluster-n
  18. hinterland
  19. hinterland1
  20. hinterland2
  21. opti
  22. world
  23. buffer
  24. cc
  25. cc_max
  26. cc_max_2050
  27. cc_change
  28. mi
  29. food
  30. climate
  31. urban
  32. foodm
  33. foodm2
  34. foodm3
  35. final