Extreme temperatures have set all-time records in several countries this summer. In Ireland, according to Met Eireann, last summer (2022) was the twelfth year in a row where temperatures were above average. Cork Moore Park-station, for example, broke its all-time temperature record reaching the 30.6ºC on August 13. A similar situation happened in the Netherlands that recorded the highest temperatures for the month of July. And in Spain, according to AEMET, this summer has been one with the highest average temperature in the historical series. The heatwave experienced on 19th of July-2022 lasted a total of 18 days, which was the second longest on record, affecting a total of 44 provinces.

All this left a balance of several impacts ranging from increase of deaths attributable to excess of temperature, as well as tens of thousands of hectares burned, losses in agriculture, and many other direct and indirect impacts such as increased electricity consumption or productivity problems both at work and school derived precisely from these episodes of extreme heat.

The most worrying thing is not that all these episodes confirm the global warming, but that what is coming is even worse, because if we continue on the same path, heatwaves will become more frequent and more intense every year, causing increasingly devastating impacts.

However, not all regions and municipalities in Europe will experience this phenomenon in the same way, so Tecnalia climate change team has developed a climate service as part of the European REACHOUT project that provides interactive panels and maps that allow easy visualization of the frequency and severity of these extreme heat episodes at different regional scales (municipality, province and/or autonomous community) for the past and for the future, taking into account historical data (e-OBS) and independent and reliable climate projections (EURO-CORDEX) from the Copernicus Climate Change Service of Copernicus, available in the Copernicus Climate Data Store (CDS).

Risk levels

The plans for alert, prevention and control of the effects of excess temperature on health assign different risk levels according to the number of consecutive days on which the established maximum and minimum temperature thresholds are exceeded. In the region of La Rioja, for example, the maximum temperature threshold is set at 36ºC and 18ºC for the minimum. Following the same approach, REACHOUT has established 3 risk levels linked to the 95th and 90th percentiles of the maximum and minimum temperatures respectively, considering a warning level (yellow) when there are 2 consecutive heatwave days, considering an alert level (orange) when there are 3 or 4 consecutive heatwave days, and considering an alarm level (red), considered when there are 5 or more consecutive heatwave days. This last one involves a clear risk for the population, endangering the physical integrity of some of its sectors and population.

Evolution of heatwaves in Europe

Imagine having to endure temperatures above 40 degrees Celsius for 21 consecutive days. This is what the inhabitants of Seville experienced this year and what municipalities such as Milano could experience in the middle of this century (2060) and cities as Logroño could experience at the end of this century (2090) according to the projections estimated by some climate models considering the most pessimistic greenhouse gas and aerosol scenario RCP8.5.

This future evolution of heatwaves is exactly what the Thermal Assessment Tool easily allows to visualize, by providing interactive panels showing the  average number of risk events projections (warning, alerts and alarms) as well as the average number of heatwave days per risk level for the coming decades.

Figure 1. Plots with the future evolution of the heatwaves for Logroño and Milano obtained using the Thermal Assessment Tool developed by Tecnalia.

Additionally, the tool provides an easy and friendly way to visualize and search information regarding historical heatwaves experience in the past by providing an interactive map and an interactive plot where user can zoom into to easily obtain specific information of previous experience heatwaves.

Figure 2. Each bubble represents a heatwave event, the x-axis represents the year, while the y-axis represents the date within that year. The size and colour of each bubble represent the duration and maximum temperature, respectively.

Adaptation strategies

The trend in the cities and regions that are most affected by the overwhelming impact of global warming is undoubtedly to identify adaptation strategies to reduce or at least mitigate the impacts. Knowing this information is therefore crucial to improve the adaptive capacity of regions and cities as it helps stakeholders to design adaptation plans and regional policies in line with their future risks.

The tool is currently available for 7 city-hubs, Logroño (Spain), Milan (Italy), Athens (Greece), Cork (Ireland), Lillestrøm (Norway), Gdynia (Poland), Amsterdam (Netherlands) for which Tecnalia has developed several co-creation workshops to identify the needs of the cities and establish the functionalities of the tool. The tool will continue to be extended in the second and third year of the REACHOUT project, incorporating high-resolution maps of the average surface temperature at city scale to better visualize the areas with the highest heat concentration, which will also enable future interventions to be planned at city scale.

This tool has been developed as part of the REACHOUT project, funded by Horizon Europe grant no. 01036599.

 Access the REACHOUT website