Analyzing effect modifiers of the temperature-mortality relationship in the Paris region to identify social and environmental levers for more effective adaptation to heat.

Adaptation to heat is a major challenge for the Paris region (France). Based on fine-scale data for the 1,287 municipalities of the region over 2000-2017, we analyzed (time-serie design) the temperature-mortality relationship by territories (urban, suburban, rural), age (15-64 and ≥ 65) and sex, and explored how it was modified by vegetation and socio-economic indicators. Heat was associated with an increased mortality risk for all territories, age groups, sex, and mortality causes. Women aged 65 and over residing in the most deprived municipalities had a relative risk (RR) of deaths at 29.4 °C (compared to 16.6 °C) of 4.2 [3.8:4.5], while the RR was 3.4 [3.2:3.7] for women living in less deprived municipalities. Actions to reduce such sex and social inequities should be central in heat adaptation policy.

Between progress and obstacles in urban climate interdisciplinary studies and knowledge transfer to society.

Cities modify their local climate, and at the same time they suffer from the local impacts of climate change. Our paper discusses the progress and obstacles in three active research topics that contribute to increasing the capability within the urban climate research community for transferring local climate knowledge to society. The first is linked to the production of urban surface descriptions useful for urban climate studies. The concept of local climate zones is now widely used to represent urban climate variability at the neighborhood scale. Land-use, morphological, architectural, and social data are also needed, and those are being gathered using different approaches. The second is linked to the necessity for producing information directly connected to their effects on society. This requires a strong multidisciplinary approach, and nowadays impact studies are not limited to one dimension but instead cover multiple dimensions. The third is to transfer all this information to city practitioners, so that urban climate features are considered, among many other aspects, in city management. For urban planning, cartographic tools have been introduced to include urban climate diagnosis as well as recommendations for future urbanization.