Abstract

To what extent are spatial planning policies that lead to alternative urban configurations effective in matching energy consumption scenarios for climate change adaptation? And what is the economic cost of effective spatial planning scenarios that involve the spatial re-adjustment of agents, activities, services and settlements?

- How to consider the specific interactions that exist between global and regional climate change, and urban climate at city-scale?

- How to translate in a relevant and physically-based way the impact of an altered climate on comfort and vulnerability of urban population?

- How to realistically assess the possible adaptation strategies by taking into account environmental benefits, costs, and socio-economic consequences? .

These questions are crucial as they address the issue of whether urban planning and spatial policies can lead to effective strategies in response to climate change. Modeling and analysis of climate change have been long dominated by aggregate approaches with a national and international perspective. This has gone along with a neglect of local spatial organization.

Our analysis aims to shed light on the potential contribution of the spatial dimension of an economy to local adaptation strategies to climate change and focuses its attention on a complementary local–urban scale of analysis which can inform the design of spatial planning and policy for adapting to climate change. The relevance of this is underlined by empirical evidence and data.

Cities bring together 50% of the world population, and this share exceeds 80% in developed countries. Such population concentration gives rise to social, economic, and environmental concerns. Among these, the issue of the specific micro-climate characterizing the urban areas is of particular interest in that the so-called Urban Heat Island (UHI) effect could create serious consequences on public health when it comes
to considering the overall temperature increase due to climate change. Particularly, the vulnerability of urban areas to an expected increase in the frequency and intensity of heat waves is what is raising the public and institutional concern and pushes them to search for solutions.

In this context, the Vulnérabilité URbaine aux épisodes Caniculaires et stratégies d’Adaptation (VURCA) project proposes an interdisciplinary approach where both environmental, technical and socio-economic aspects are considered, in order to provide first insights on the complex interaction between city economies and climate change and on the viability and effectiveness of identified adaptation options. From a methodological perspective, this is expected to be achieved by integrating in a unique investigation framework the outcomes from three
different analytical methods:

- a climate model,

- a urban-weather model

- and a coupled housing-transportation model.

The work program aims to develop the two indicators from such an integrated framework. The heat-wave seriousness indicator, which links large-scale
climate information to local seriousness of the event (defined from comfort index and energy consumption at city- and neighbourhood-scale).
climatique. La modélisation et l’analyse de ce dernier

The innovation is that this indicator will take into account the specifics of urban weather. Second, urban climate simulations will be performed
for a given heat wave – the 2003 event in Paris – and a large range of stylized cities based on simple socio-economic scenarios taking into
account population change, economic development, and various urban development strategies (including urban planning strategies to adapt
to climate change and to mitigate future emissions, e.g., compact city, city with parks, etc.

The second indicator, namely the heat-wave
urban-vulnerability indicator, that relates the characteristics of urban morphology to the vulnerability to a 2003-like event. Finally, the
economic costs of several adaptation strategies (e.g. influence on housing prices (including quality index) or transportation demand) and the
benefits (in terms of comfort and energy consumption) will be assessed to inform on the overall efficiency of these adaptation strategies.

We see the application mainly in the policy area, to support the view that the spatial planning is relevant not only in the mitigation strategies,
but also to adaptation measures in response to global warming