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Unprecedented urbanization and challenges to model them in IAMs
S H OB H A KA R D H A KA L
S C H O O L O F E N V I R O N M E N T R E S O U R C E S A N D D E V E LO P M E N T
A S I A N I N S T I T U T E O F T E C H N O LO G Y, T H A I L A N D
International Scientific Conference 7-10 JULY 2015 Paris, France Session S3322(a) 3-4.30 PM UPMC, 8 July 2015
Urbanization’s wedge in future emission profile and implication of alternative pathways of urbanization BRIAN O’NIELS ’S L IMITED WORK
KAREN SETO’S WORK FROM URBAN LAND EXPANSION
FEL IX ’S PNAS WORK ON URBAN TYPOLOGY
RECENT EST IMATION BY SE I -USA FOR MICHAEL BLOOMBERG
DANIEL MUELLER’S WORK ON INFRASTRUC TURE STOCK
Global urbanization trends
66%
30%
54%
3.2 bn
2.46 bn 51% Asia 36% Africa
3.88 bn
6.34 bn
700 mn
Source: UN DESA World Urbanization Prospects 2014
Urban land could expand up-to 3 time in 2000-30 55% of global land in 2030 is expected to be developed in 2000-30
Schneider et al., 2009; Angel et al., 2011; Seto et al., 2011, 2012
Implications of urbanization 71-76% of energy-related global CO2 emissions are from energy use in
cities (IPCC, 2014; GEA 2012) (some definitional complexities are there)
Urbanization-income nexus higher urban incomes correlated with higher energy and GHG emissions (Poumanyvong and Kaneko, 2010; IPCC 2014, GEA 2012)
Bottom up analyses show that Cities in non-Annex I countries have, generally, higher per capita final energy use and CO2 emissions than respective national averages – majority of new urbanization will be in non-Annex
Source: GEA, 2012; Grubler et al., 2012; IPCC, 2014
Based on 254 cities final energy use
Stochastic Impacts by Regression on Population, Affluence and Technology (STIRPAT) model and a sample of 88 countries for the period 1975–2005 Poumanyvong and Kaneko, 2010, Ecological Economics.
• The existing infrastructure stock of the average Annex I resident • 3 times that of the
world average • about 5 times higher
than that of the average non-Annex I resident
• The build-up of massive
infrastructure in developing countries will result in significant future emissions
Müller et al., 2013
Total CO2 emissions (per capita) needed to build up today’s infrastructure
Future CO2 emissions if developing countries catch up to average developed country level.
Future infrastructure emissions alone could require about a third of the 2°C emission budget.
Infrastructure demands large emissions
Müller et al., 2013
> a third of the 2°C emission budget by 2050 (1,000 GtCO2)
• The existing infrastructure stock • Average Annex-I
resident is 3 times that of the world average
• About 5 times higher than average non-Annex I resident
China’s urbanization
• 6-7 trillion $ investment • Infrastructure lock-in • Guiding new urbanization
Bai et al. 2014, Nature 1 6 0 | N AT U R E | VO L 5 0 9 | 8 M AY 2 0 1 4
Urban abatement by sector in the urban action scenario, 2030 and 2050
Urban action could help deepen the aggregate, global ambition of current national pledges
Chart sources (other than this study): BAU and “reference scenario” differ only in their assessment of energy-related CO2 emissions: BAU uses IEA’s 6DS scenario, reference uses 4DS; for other gases, both scenarios use the average of BAU scenarios in the IPCC AR5 scenario database, 2-degree pathway from Rogelj et al
C40 (2015)- A report to the UN Secretary-General from the UN Secretary General’s Special Envoy for Cities and Climate Change, in partnership with the C40 Cities Climate Leadership Group Advancing climate ambition: cities as partners in global climate action
GHG emissions and emissions avoided in the urban action scenario
Urbanization’s energy wedge
Potential of an urbanization wedge in energy use. (A) Urbanization wedge characterized by median business-as-usual (BAU) and low-carbon urban development (LCUD) scenarios. (B) Uncertainty in scenarios for the different world regions. The centerline is the median, the top and bottom of the boxes are the 25th and 75th percentiles, and lines present overall range. OECD90, OECD countries in 1990; LAM, Latin America and the Caribbean; MAF, Middle East andAfrica; REF, reforming economies of Eastern Europe and the former Soviet Union.
Felix Creutigz etc al., PNAS, 2013
• Dataset of 274 cities • Based on the clustering and scaling sample
cities statistically • If current trends in urban expansion
continue, urban energy use will increase more than threefold, from 240 EJ in 2005 to 730 EJ in 2050
• Urban planning and transport policies can limit the future increase in urban energy use to 540 EJ in 2050 and contribute to mitigating climate change
Urbanization as a big elephant in the room cannot be ignored in global models such as IAMs
The ability if IAM to characterize and model urbanization and infrastructure is extremely limited
Infrastructure likely to embody over 1/3rd of global emission budget till 2050 (to stay under 2 degree) is big elephant
In some of the models, demographic features such as population density and migration are considered – some models might have a better prospects to incorporate urban land expansion
Extension of SSP and SPA scenarios reflecting urbanization is also an opportunity
Forward IAM community must take this challenge
I argue that next frontier in global and regional IAM models lie in addressing the full scale implications of the type and extent of urbanization in economic, infrastructural, social, geosphere and bio-spherical domains
We must open a much needed dialogues and discussions on how to take-on this challenges in the modelling community to develop a new generation of Integrated Assessment Models
