Global warming induces climate change and increases weather extremes, such extreme heat events, which enhances public health impacts. Since the beginning of this century unusual summer heat extremes occurring in Germany at higher frequency, longer duration, and with new air temperature records. During recent heat events of 2018 and 2019 record temperatures were measured by duration (up maximum of 18 consecutive days above 30 °C in 2018) and maximum (41.2 °C in 2019). Daytime heat burden appears quite often like a dome affecting regional areas, while nighttime minimum temperatures above 20 °C emerge much more frequent in the densely populated settlements of built-up city centres and conurbations e.g. in the Rhein-Ruhr and Rhein-Main region compared to their suburbs (factor > 3), known as urban heat island effect.
There is evidence that episodes of extreme summer heat and poor air quality pose significant consequences for public health, as single impact and in combination. Several extraordinary heat extremes in different regions of Germany resulting in acute heat-health impacts (morbidity and mortality of non-communicable diseases) particularly between 2003 and 2019, predominantly in the elderly population. Results reveal that heat events are accompanied by increased ozone concentration, especially during the most intense and longest heat events, resulting in a considerable number of excess mortality cases. The mortality risk of both ischemic heart and respiratory disease increases sharply above a daily mean temperature of about 18 °C and reaches an increase in mortality of up to 40% on very hot days. Mortality due to chronic respiratory diseases is even more affected with a steeper increase. In conclusion, the duration and the intensity of extreme heat episodes show a significant increase of heat related mortality and morbidity. The results obtained emphasize the need to improve heat health prevention and significant climate change mitigation measures.
Mots clés : heat extremes|health impacts|climate change|heat-related mortality|Germany