Rising night-time temperatures as an indicator of climate change in coastal tourist destinations. Current situation and future scenarios

Abstract

The global warming caused by climate change is being especially noticeable in minimum temperatures. Thus, estimations foresee a rise in night-time temperatures throughout this century, which would entail an increase in the intensity, frequency and duration of episodes such as tropical and equatorial nights, as well as a reduction in those considered cool. undoubtedly, this phenomenon represents a major problem for coastal tourist destinations, since their main attraction factor, their climatic conditions, is at risk. T he aim of this research is to characterize the evolution of tropical and equatorial nights, i.e., those whose minimum temperature exceeds 20ºc and 25ºc, respectively, as well as cool nights (those thermally below the 10th percentile of the minimum temperatures of the entire series), in various tourist destinations in the canary islands and the Mediterranean basin in recent decades, as well as estimating, based on the climate projections contained in the latest report of the intergovernmental panel on climate change (ipcc), their variation in the middle and end of this century. for this purpose, the climate series of nineteen coastal locations in ten countries were analysed: spain, france, italy, croatia, greece, turkey, israel, egypt, tunisia and algeria. in order to estimate future conditions, the anomalies projected by the ipcc sixth assessment Report for minimum temperatures by region for the decades 2040-2059 and 2080-2099 were taken into account. according to the results obtained, all destinations show a positive trend in the occurrence and, especially, in the duration of tropical nights in recent decades. for example, in Marseille, the percentage of tropical nights per year is currently around 10%, a figure that was around 2% until the middle of the century. in terms of duration, while such events used to occur in isolation there, some now exceed even four consecutive nights. as far as equatorial nights are concerned, although in some cases there is an increasing trend, their exceptional nature prevents us from concluding that there has been a generalized increase in the number of equatorial nights. in all cases, particularly in the ssp5-8.5 scenario, an exponential increase in tropical and, especially, equatorial nights is predicted, which by the end of the century will cease to be exceptional events and will become recurrent phenomena, resulting in several of them occurring every summer in all destinations.