Heat stress increase under climate change twice as large in cities as in rural areas: a study for a densely populated midlatitude maritime region

Urban areas are usually warmer than their surrounding natural areas, an effect known as the urban heat island effect. As such, they are particularly vulnerable to global warming and associated increases in extreme temperatures. Yet ensemble climate-model projections are generally performed on a scale that is too coarse to represent the evolution of temperatures in cities. Here, for the first time, we combine unprecedented long-term (35-year) urban-climate model integrations at the convection-permitting scale (2.8km resolution) with information from an ensemble of general circulation models to assess temperature-based heat stress in a densely populated mid-latitude maritime region. We discover that the heat-stress increase towards the mid-21 st century is twice as large in cities compared to their surrounding rural areas. The exacerbation is driven by the urban heat island itself, its concurrence with heat waves, and urban expansion. Cities experience a heat stress multiplication by a factor 1.4 and 15 depending on the scenario. Remarkably, the future heat stress surpasses everywhere the urban hot spots of today. Our novel insights exemplify the need to combine information from climate models, acting on different scales, for climatehange risk assessment in heterogeneous regions. Moreover, these results highlight the necessity for adaptation to increasing heat stress, especially in urban areas.

Jaar van publicatie:2017

BOF-keylabel:ja

IOF-keylabel:ja

BOF-publication weight:6

CSS-citation score:4

Authors from:Government, Higher Education

Toegankelijkheid:Open