Building resilient and sustainable cities
World Bank and Meteo-France
Urban planning faces many policy goals
Urban forms matter for greenhouse gas emissions and energy consumption
Urban forms matter for climate-change vulnerability (urban heat island, flood vulnerability,)
Urban development competes with other category of land-use (e.g., agriculture, natural areas)
Urban development is crucial for economic development, and is a factor of social and spatial inequalities.
Building sustainable cities create unprecedented decision-making issues
Urban forms and energy consumption
Lower energy consumption in Barcelona because of:
1 - Shorter travel distance;
2 Easier use of public transport:
Source: Alain Bertaud
Urban forms and vulnerability
Temperatures are higher in cities than in rural areas, especially at night.
Example of the 2003 heat wave in Paris.
Source: CNRM, Mto-France (V. Masson, G. Pigeon, A. Lemonsu, C. Marchadier)
City Brussels Budapest LisboaMexico
YorkParis Seoul Sydney
land2.3 0.8 3.2 0.1 0.1 0.5 0.6 0.02
population10 25.3 26.3 23.9 7.8 21.2 25 24.4
GDP44.4 45.6 38 26.7 8.5 27.9 48.6 23.5
Sources: Land: Klein Goldewijk and Van Drecht, 2006; population: UN, 2006; and
GDP: OECD, 2006.
The major economic role of cities
in economic development
Urban development and spatial inequality
Reducing energy consumption
Reducing urban risks
Limiting competition for land availability
Actions need to be assessed
along several dimensions
It is crucial to look for synergies between these different policy goals.
It is the objective of the Green Growth Strategies, on which the WB is preparing a report
(available March 2012).
A complement to economic analyses
Adaptation & incertitude
Resilient urban planning means anticipation
Adaptation will require technical know-how and substantial funding.
Adaptation requires also anticipation, especially in sectors with long-term investments:
Water management infrastructure (lifetime: up to 200 years);
Energy production and distribution infrastructure (up to 80 years);
Transportation infrastructure (50 to 200 years) ;
Natural disaster protections (50 to 200 years);
Urbanism, housing and architecture (25 years to centuries).
These infrastructures represent more than 100% of GDP.
In most developing countries, cities and infrastructures are currently being built and it is urgent to take climate change into account.
e.g., the Bouregreg
One possible future climate
Climate analogues in 2070, Hadley Centre Model, SRES A2
A new building in Paris needs to be adapted to the current climate of Paris,
and to the future climate of Paris, i.e. the current climate in Cordoba.
Climate analogues in 2070, Mto-France Model, SRES A2
A new building in Paris needs to be able to cope with any of the possible future
Uncertainty in sea level rise
Source: IPCC (2007)
Public action for sustainable cities
Five domains of public action
Creating and distributing information
Information production and diffusion to the population
Early detection of climate change signals
Coordinating private-actor actions
Need for cooperation between private and public actors
Role of norms and regulations (e.g., building norms, insurance)
Regional and urban development plans
Avoiding negative consequences of adaptation actions
Change in water use (e.g., irrigation)
Air conditioning and energy consumption
Preserving equity and alleviating poverty
A fraction of the population cannot afford adaptation investment and need support
Direct investment actions
Transport, water management, public buildings, etc.
Looking for robustness
Learn ActLearn and revise
It is critical to select strategies that can be revised over time, as a function of
new information and knowledge.
Looking for robustness
Selecting no-regret strategies that bring benefits even in absence of climate change, and for most climate scenarios:
Most Disaster Risk Reduction Actions;
Improvement in building norms;
Favoring reversible strategies over irreversible ones (avoid lock-ins):
More restrictive land-use plans;
Investing in low-cost safety margins:
Drainage infrastructures in Copenhagen.
Reducing investment lifetimes:
Housing building quality and lifetime in flood-prone areas (Building strong?)
Favoring financial and institutional (soft) adaptation over hard adaptation:
Early warning, evacuation and insurance vs. sea walls and dikes.
When uncertainty is large, the main objective is to avoid lock-ins in vulnerable situations, and to keep the possibility of adjust in case pessimistic scenarios reveal correct.
There are many suboptimal situations that can be corrected, creating no-regret opportunities.
Uncertainty cannot justify inaction.
But uncertainty requires using different decision-making methods.
It is dangerous to implement an optimal strategy, designed for only one scenario.
Strategies should be designed to increase robustness and resilience, and account for many scenarios.
Several definitions for adaptation
Current risk level optimal risk level
Adaptation gap reduction
And it is not a two-stage process, but a
Plan National dAdaptation en France
Premire phase (2008-2009):
Slection de 2 scnarios climatiques et conomiques
Approche participative pour identifier les impacts du changement climatique
Gouvernement, autorits locales, employeurs, syndicats de travailleurs, ONG
Seconde phase (2010):
Approche participative pour identifier des mesures dadaptation
Evaluation participative, laide de mthodes simples, avec 6 mtriques (urgence, cot et bnfice montaire, sant, biodiversit, qualit de vie, impact redistributif), et des critres de robustesse.
Evaluation dtaill des mesures:
Cohrence avec les autres objectifs politiques
Robustesse lincertitude climatique & conomique
Si possible et ncessaire, analyse conomique et financire dtaille
Dfinition dindicateurs de succs
Revue et rvision tous les 5 (?) ans
Un moyen de fixer des priorits
Pertes lies aux inondations Mumbai
Pertes dues la crue centennale dans
diffrents scnarios dadaptation Ladaptation peut rduire les
pertes en de de leur niveau
Ces actions sont sans regret
Pourquoi ces actions nont-elles pas t mises en place?
Manque de volont politique et faible poids politique des