Why is the content of this map important?
It is important for the human well-being that the body can cool down after a hot day. In tropical nights, the temperature stays above 20°C. During these nights, it is more difficult for the human body to cool down, especially for elderly or sick people. Therefore, an increase of tropical nights can lead to a rise of mortality.
Which sectors are affected by this result?
An increase of tropical nights influences human well-being directly. This impacts the health sector. The energy sector is affected by a higher electricity demand during summer due to increased use of air conditioning.
What is shown on the maps?
The maps show the number of tropical nights per year (i.e., nights with a minimum temperature of 20°C). Under present day climate, regions in Southern Europe are most affected by tropical nights. These regions also show the largest increase under a +2°C global warming.
Details and further information:
Under present day conditions, more than four tropical nights per year occur mainly in Southern Europe. In Central, northern- and Eastern Europe, tropical nights are very rare events. Under a +2°C global warming, the possible number of tropical nights increases. Projections show that more than 30 tropical nights per year can occur over large areas in Southern Europe. Under present day climate, this happens only in a few restricted areas. Also in Central and Eastern Europe, a couple of tropical nights per year are projected to occur. Areas affected under present day climate in Southern Europe show the largest increase in tropical nights. For a more complete analysis of the impact of tropical nights on health, other factors such as humidity, have to be taken into account.
To investigate this, the ensemble mean of the five mandatory climate simulations is used. Hence, the ensemble consists of 5 simulations in total.
Claas Teichmann
Climate Service Center Germany (GERICS), Germany