In several countries, despite increasing episodes of extreme temperatures, heat-related health impacts seem to be decreasing. This highlights the effectiveness of current prevention measures. Nevertheless, projections for the Region clearly indicate that without adequate efforts for heat–health adaptation to climate change, heat-related exposures and the associated health impacts could increase substantially. Such projections, combined with long-term trends of ageing and urbanization, strongly warrant the adoption of a long-term perspective to manage the health effects of temperature in the context of a changing climate.

The WHO European Region is warming, fast and dangerously. The year of inception of this report (2019) was the warmest calendar year on record in the northern part of the Region, as well as the second warmest year globally ever recorded. It was not an outlier, however: according to the European Centre for Medium-Range Weather Forecasts (ECMWF), 11 of the 12 warmest years in the Region have all occurred since 2000 (ECMWF, 2020). Both annual and seasonal average temperatures show a clear warming trend over the last four decades. Warming trends in the Region are consistently measured and statistically significant (Gil-Alana & Sauci, 2019); they are routinely evaluated by comparing recent measurements with climate data dating back to pre-industrial times (Fig. 1).

 

Beyond average temperatures, heat waves are also growing in frequency, in relative and absolute intensity and in duration, with a significant increasing trend in the Region since 1950 (Donat et al., 2013). The number of hot days has increased by 10 days per decade since 1960 in most of southeastern Europe and Scandinavia (Russo, Sillmann & Fischer, 2015). A comprehensive study of 59 weather stations in the eastern part of Europe, the Caucasus, the Russian Federation and Central Asia, using data from 1951 to 2010, found a clear increasing trend in the frequency of extremely hot summers (with an average temperature equal to or greater than the long-term average plus two standard deviations). While one extremely hot summer occurred during the first 30 years, five occurred during the last 10 years of the study period (Twardosz & Kossowska-Cezak, 2013).

An increasing trend in heat-wave frequency and intensity has been observed in Poland, although the increase is statistically significant at only about 60% of analysed stations (Wibig, 2017).

 A recent study examining 100 years of data (1917– 2016) found significant increasing trends in the frequency, intensity and duration of heat waves in most of central Asia (which in this study refers to Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan), and especially during the last 50 years in western central Asia (Yu et al., 2020). In Georgia, statistical analysis demonstrated significant increases in the number, intensity and duration of low- and high-intensity heat waves (Keggenhoff, Elizbarashvili & King, 2015). Data also indicate that the frequency and duration of heat waves increased in the western part of Turkey between 1965 and 2006 (Unal, Tan & Mentes, 2013). Other parts of the WHO European Region, including most countries in the Mediterranean basin, have also experienced an increase in the frequency and intensity of heat waves, as has Israel (Green et al., 2013), where record high temperatures were registered as recently as May 2019 (WMO, 2019).

The Copernicus Climate Change Service (C3S) provides access to quality-controlled data about the past, the present and the future of global climate. These include historical observations, global hourly data about all main meteorological parameters extending from 1979 to near-real-time (five-day latency), seasonal predictions for the next six months, and global and regional climate projections. Given the impact, climate variability and change is having on societies, and the complexity of the processing procedures associated with the analysis of climate data, C3S makes high-quality, up-to-date datasets available in an unrestricted manner to all users. The service also provides a free cloud environment in which to process the data and transform it into usable and useful information.

 The following example represents a way in which C3S data can be used to inform stakeholders and policy-makers. Fig. 2 shows the trend in change in degrees per year of the surface air temperature for the summer months (June, July and August) during 1979–2019. The values were calculated using a linear trend on the ECMWF re-analysis data for the surface temperature. The figure shows European surface air temperature anomalies relative to the 1981–2010 average, from January 1979 to August 2019. The first graph shows the mean anomalies for every month and the second graph shows the running 12-month averages.

 The plot and the code to generate this plot are freely available online on the C3S Climate Data Store platform for anyone to consult or reproduce. The user can also analyse past temperature anomalies for specific months and years through the C3S monthly climate bulletin explorer application.

Greater temperature increases are expected in the north of the Region in winter (potentially decreasing cold-related mortality), and in the southeast and the Balkans in the summer (EEA, 2017). The increase in warming magnitude is expected to be most dramatic in the central southern part of the Region, while the increase in the duration of hot conditions is expected to be most pronounced in the Mediterranean (Guerreiro et al., 2018). Nevertheless, extreme heat events may also occur in northern areas that are currently not strongly affected by heat waves (Nikulin et al., 2011). 

  In central Asia, assuming a 4 °C increase in global temperatures by the end of the century, around 80% of the land area could be affected by events hotter than three standard deviations beyond the long-term temperature average, and about 50% of the land area could be affected by events hotter than five standard deviations by 2071–2099 (Reyer et al., 2017). In general, solid high extremes temperature projections under climate change are comparatively scarce in the published literature for most areas of the Region beyond EU countries. This scarcity poses a clear challenge for evidence-based heat–health action and health adaptation in these areas.

Both average increases in temperature and projected increases in frequency, intensity and duration of heat waves are of concern for public health. Globally, under an increasingly probably high warming scenario,1 every second summer will be as warm or warmer than the hottest summer ever experienced by the population during 1920–2014 (Lehner, Deser & Sanderson, 2018). The increase in the probability of extreme heat waves in large urban areas in the Region is a particular concern, on account of population concentration, urban landscape and demographic factors (explored later in this report). A recent study (Smid et al., 2019) estimated heat- wave2 probability increases for 31 European capitals (the capitals of the 28 EU countries before 2020, plus Moscow, Russian Federation; Oslo, Norway; and Zurich, Switzerland), and found that all the European metropolitan areas investigated will be more vulnerable to extreme heat in the coming decades (Fig. 3). The number of days with high heat stress levels is increasing in both northern and southern parts of the Region. The potential for hazardous exposure to extreme heat has been worsening in recent decades and will continue to do so across Europe.

ROTTERDAM TEAM

Climate change and  health

The recent WHO report on Climate change and health (LINK TO REPORT) illustrates how heat extremes have serious impacts on public health worldwide. The effects of heat mostly occur on the same day and in the following three days. Elderly people are a group who have a high risk on negative health effects due to the increase of the frequency and intensity of heat waves in combination with the presence of (co)morbidity. Also, people living in cities have a larger risk on negative health effects because of so-called heat islands which are often located in socially and economically deprivated areas. Other vulnerable groups at greater risk include people with chronic conditions (such as cardiorespiratory diseases, endocrine system disorders, mental health disorders, metabolic disorders and kidney disorders), pregnant women, small children, workers, migrants and travellers. Age, pre-existing medical conditions and social deprivation are key factors that make people experience more adverse health outcomes related to heat and extreme temperatures. We differentiate the direct and indirect effects of exposure to heat. Direct effects are heat stress and dehydration or heatstroke. Indirect effects are for example worsening of cardiovascular and respiratory diseases, kidney diseases or electrolyte disorders (WHO Regional Office for Europe, 2018).

In the last decade, the quantity of literature on factors affecting vulnerability to heat has greatly increased. There is substantial literature and good practices on how to address or prevent heat-related health effects. However, the literature on the evidence of these interventions is poor. At the same time, a lot is developed and being implemented at three levels on which one can address climate change-related health problems: at the individual level (micro), at the level of the house or the organisation (meso) and at the level of the community/municipality (macro).

Nowadays, heat health action plans (HHAPs) are developed and implemented by both national and local governments. HHAPs are supposed to provide tailored advice, implement specific prevention measures and actively monitor those during heat waves and to evaluate the results and adapt the action plan according to these results.

 The individual and interpersonal level (micro)

At the individual level interventions are aimed at adaptive behavior and the introduction of products that stimulate cooling. Besides that, providing information and giving advice are important interventions too. Neighbours, family, caretakers and care providers play an active role in all interventions as mentioned.

The level of the physical environment and institution (meso)
Exposure to heat happens frequently indoors. Indoor exposure to overheating occurs through a combination of building and dwelling characteristics, occupancy profiles and behavioural factors.  While some of the characteristics of a building that can lead to overheating cannot be modified (such as location), there are significant possibilities to prevent or decrease the chance of overheating. Passive cooling interventions such as solar shading, opening the windows at night, cooling by air through narrow openings in the building, shading of the roof, and cooling by vaporising water can result in health protection from heat while minimizing energy consumption.  A wide range of active cooling technologies is available. Air conditioning is very effective but has a number of drawbacks, including equity of access and environmental and social impacts, and may be a clear example of a non-sustainable technology. The promotion of sustainable technologies is recommended (VRAAG: ZIJN DIE ER AL?).

Residences and care organisations have heat health plans in order to guide their professionals in taking good care of people and themselves during periods of (extreme) heat. Health professionals should be alert to heat illness risk factors, diagnosis and management. But also interventions on buildings and the built environment are options they use to protect their professionals and patients from heat. In general, the promotion of a sustainable healthcare system/organisation may in the long term be the most effective scenario.

The level of the community/municipality (macro level)

Heat health action plans should be linked with climate change policies as well as with disaster/emergency response policies, environmental policies and health policies. This may result in more synergy and gains. For example, urban management interventions such as developing green spaces reduce termal stress and are therefore good examples of how it relates to public health benefits. Tools for intersectoral action are lacking to allow public health agencies to influence urban management decisions in order to protect health from heat

Insert table 2 (page 42 WHO report) at the paragraph of prevention

Insert figure 5 (page 29 WHO report) at this paragraph.

 Besides these three levels we also distinguish interventions aimed at short term (in order to reduce the health risks at periods of extreme  heat) and aimed at long term (in order to prevent health risks at periods of extreme heat).

 Two general figures

 From: https://www.who.int/news-room/fact-sheets/detail/climate-change-heat-and-health#Overview

 

 Source: https://www.who.int/news-room/fact-sheets/detail/climate-change-and-health

 

Ad to individual level

 

Source: Sorensen, C., Hess, J  (2022). Treatment and Prevention of Heat-Related Illness. In:

N Engl J Med 2022; 387:1404-1413.