Observed Trends in Thermal Stress at European Cities with Different Background Climates

Abstract

Intensification of extreme temperatures combined with other socioeconomic factors may exacerbate human thermal risk. The disastrous impacts of extreme weather during the last two decades demonstrated the increased vulnerability of populations even in developed countries from Europe, which are expected to efficiently manage adverse weather. The study aims to assess trends in the exposure of European populations to extreme weather using updated historical climatic data in large European cities of different local climates and a set of climatic and bioclimatic indices. Colder cities experience higher warming rates in winter (exceeding 1 °C/decade since the mid-1970s) and warmer cities in summer. Hot extremes have almost tripled in most cities during the last two or three decades with simultaneous advancing of hot weather, while northernmost cities have experienced an unprecedented increase in the heat waves frequency only during the last decade. Bioclimatic indices suggested a robust tendency towards less cold-related stress (mainly in cold cities) and more heat-related stress in all cities. A doubling or tripling in the frequency of heat-related ‘great discomfort’ was found in southern cities, while in the cities of northern Europe, heat-related ‘discomfort’ conditions are becoming increasingly more frequent and have nearly quadrupled during the last decade.

Response of Urban Heat Stress to Heat Waves in Athens (1960–2017)

“…These findings for Athens are similar with the results reported in other Mediterranean or eastern Europe cities. For instance, a significant increase in both the number of HW days and the number of long HWs have been recently reported in Madrid, Palma, Nicosia, Rome, Sofia, Zagreb and Ljubljana [19,61,62].…”

Outdoor Universal Thermal Comfort Index Climatology for Alaska

“…The more than 23% growth in Alaska's population mainly increased the outskirts of the three major cities (Anchorage, Fairbanks, Juneau). Recent studies showed that increasing urbanization and improved urban planning, among other things, altered the thermal stress in European cities of different background climates over time [53]. Given the few urban sites in Alaska, of which many have only short time series, the assessment of small-scale differences in thermal comfort and planning for its improvement remain a challenge.…”

Meteorological and Ancillary Data Resources for Climate Research in Urban Areas

“…E-OBS also allows grid box average comparisons with the results of Regional Climate Models for validation purposes [25][26][27]. These datasets were used in various urban climatology studies relying on observations addressing the challenges of climate change in European cities, e.g., assessment of the impact of climate change on thermal performance of residential buildings [28]; and change in extreme heat/cold stress [29][30][31].…”