GE-I-1: Heat exposure and Public awareness

2019 Monitoring Report on the German Strategy for Adaptation to Climate Change

Table of Contents

 

GE-I-1: Heat exposure

Apart from the increases in annual mean temperatures, the past forty years also show a trend towards rising heat extremes. Especially the number of hot days has increased significantly. As far as tropical nights are concerned, it has so far not been possible to discern a trend. The same is true for the number of heat warnings.

The graph shows the number of heat warnings from 2005. There is no trend. From 1951, the area averages of hot days with increasing trend (between one and 19 days per year) and tropical nights without trend (between one and two days) are shown.
GE-I-1: Heat exposure

The graph shows the number of heat warnings from 2005. There is no trend.
From 1951, the area averages of hot days with increasing trend (between one and 19 days per year) and tropical nights without trend (between one and two days) are shown.

Source: DWD (Heat Warnings - German Climate Atlas)
 

GE-I-1 (addendum): Public awareness of health problems due to heatwaves

In 2016 half of the respondents already anticipated a strong or very strong impairment of their future physical wellbeing due to heatwaves. In 2012 this had been true for just a third of respondents.

The stacked column graph shows population survey results for 2012, 2014 and 2016. The percentage of people who feel very strongly and strongly affected has increased, while the percentage of those who feel less or not at all affected has decreased. Both groups roughly balance each other out.
GE-I-1 (addendum): Public awareness of health problems due to heatwaves

The stacked column graph shows population survey results for 2012, 2014 and 2016. The percentage of people who feel very strongly and strongly affected has increased, while the percentage of those who feel less or not at all affected has decreased. Both groups roughly balance each other out.

Source: BMU & UBA (Umweltbewusstsein in Deutschland)
 

Heat exposure raises health risks

Increasingly, climate change will, apart from rising average temperatures, entail heat exposure events thus affecting health. Looking back it is possible to discern a trend since the 1970s towards an increase in hot days on which the daily maximum temperature amounts to 30°C or more. In ‘tropical nights’, temperatures do not fall below 20°C which means that recovery at night, especially after very hot days, is limited.

Contrary to hot days, tropical nights have not occurred frequently in our climes. It can be stated, however, that years with distinctive heatwaves have also regularly led to the development of tropical nights.

Strong correlations with the development of hot days are indicated by the number of heat warnings issued by DWD since 2005 as part of its heat warning system. Warnings are issued when ‘major heat exposure’ of at least 32 to 38°C ‘perceived temperature’ is forecast and night temperatures lead to inadequate cooling. If extreme heat exposure at temperatures of 38°C and more are expected, these warnings are certain to be issued; this is also normal procedure when such events are of shorter duration (see GE-R-1). Ever since the heat warning system came into operation, there have been weather–dependent fluctuations in the annual mean number of heat warnings in the so-called warning zones which follow the general outlines of administrative districts. After 2003 there were, in 2006, 2010, 2013, 2015 and also in 2018, according to the mean value calculated across the districts, on more than ten days, hot days and temperatures above 30°C. Prior to 2000 the ten-day-mark was reached only in 1976 and 1995 and exceeded only in 1994. In terms of the nationwide annual mean, more warnings were issued in southern Germany, i.e. approximately on three more days, compared to four days fewer warnings issued in northern Germany.

The hot days and tropical nights as well as heat warnings indicate weather situations injurious to health; however, they do not allow any conclusions as to how many people’s health will actually be affected. Heat exposure affects in particular older people, the chronically ill, young children and individuals who live alone. People who enjoy good health are in a better position to adapt and counteract the consequences of heat exposure more effectively. Health problems are usually caused by high fluid and electrolyte losses through sweating and inordinate stress on the cardio-vascular system owing to high amounts of heat transfer required.

In recent years, public awareness of health impacts from periods of extreme heat has increased. This is demonstrated by the outcomes of a representative survey of the German population, entitled ‘Umweltbewusstsein in Deutschland’ (Environmental Awareness in Germany)“I carried out in 20161 for the purpose of comparison with surveys from previous years. In 2016 50% of respondents stated that they expected that heatwaves would have either very strong or strong effects on their own physical wellbeing. Compared to 2012 only 30% of respondents made similar statements2. By comparison, in 2016 just 12% considered themselves not affected in any way, whereas in 2012 33% of respondents had expected to be affected.

1  BMUB – Bundesministerium für Umwelt, Naturschutz, Bau und Reaktorsicherheit & UBA – Umweltbundesamt (Hrsg.) 2017: Umweltbewusstsein in Deutschland 2016 – Ergebnisse einer repräsentativen
Bevölkerungsumfrage. Berlin, 88 pp.

2  BMU – Bundesministerium für Umwelt, Naturschutz und Reaktorsicherheit & UBA – Umweltbundesamt (Hrsg.) 2012: Umweltbewusstsein in Deutschland 2012 – Ergebnisse einer repräsentativen Bevölkerungsumfrage. Berlin, 84 pp.
I  The representative population survey (of German-speaking residents aged 14 or more years) entitled ‘Umweltbewusstsein und -verhalten in Deutschland’ (Environmental Awareness and Behaviour in Germany’ has been carried out every two years since 2000 on behalf of the BMU and the UBA. Since 2012, questions were incorporated in the survey which would supply data for the DAS monitoring indicators; from 2016 onwards, these questions were asked every four years in the environmental awareness surveys.

 

Interfaces

GE-R-1: Heat warning service

 

Objectives

Right to life and physical integrity (German Constitution, Art. 2)