Temperature and climate change
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Temperature and climate change

Air and sea temperatures have increased, and this has led to less snow and ice at the poles and in mountain regions, increased sea levels and altered precipitation patterns. When temperatures change, it may affect flora and fauna. For example, some species will disappear, and will be replaced by new species moving up from the south.


Farmers will have to adjust their crop choice, and this is already happening today: the area of maize for fodder has been increasing in Denmark over the past ten years.

Figure 1 shows that the temperature varies in Denmark across the years. The Danish Meteorological Institute, which is responsible for the measurements, has found that the average temperature for different years ranges from less than 6°C to 10°C. However, the average temperature is increasing.
If we compare the average temperatures from the earliest measurements from 1873-1900 with recent years' measurements, we see a clear increase from about 7°C to more than 8.5°C.

The lowest average temperature was measured in 1879 at 5.8°C. The highest average temperature of 10.0°C was measured in 2014.
The annual average temperature has been measured at more than 9°C thirteen times since 1872. Eleven of these years lie after 1989, the most recent year was 2019.
The average temperature in Denmark increased by about 1.5°C in the period 1873-2017.

 

 Temperature and climate change figure 1

Figure 1 The trend in Danish average annual temperature 1873-2017, measured in ˚C
Source: The Danish Meteorological Institute 2020.

Denmark will experience more variation in weather and more extreme weather. The table below is based on a short time series, but has nonetheless been included here to illustrate these variations.

 

 

Table 1 Number of days with warm spells and heatwaves, respectively
Source: The Danish Meteorological Institute 2020.

Temperature and climate change tabel 1

 

* For each day, it was calculated how much of Denmark experienced a warm spell or heatwave, respectively. For example: If an area corresponding to half of Denmark was hit by a warm spell for one day, the result for all of Denmark was calculated at 0.5 days of warm spell.
**A warm spell is when the mean value of the highest registered temperatures measured at the same place over three consecutive days exceeds 25°C.
**A heatwave is when the mean value of the highest registered temperatures measured at the same place over three consecutive days exceeds 28°C.

There are generally large variations from year to year. The year 2018 had the highest number of days with warm spells (26.0 days) and heatwaves (6.1 days). There were no warm spells in any parts of Denmark in only one out of the nine years. Heat waves are rarer and only occur around every other year in parts of Denmark.

 

Future temperatures in Denmark
The change in Denmark's average temperature over the year in the period 1981-2010 was 8.4°C . Figure 2 shows the three future periods 2011-2040, 2041-2070 and 2071-2100 in the scenarios RCP4.5 and RCP8.5. The expected change at the end of century is 3.4°C for RCP8.5 (2.9 to 4.3°C).

 

Temperature and climate change Figure 2

Figure 2 Future annual temperatures
Source: Climate Atlas vers. 2 2020.

 

Denmark's average temperature for the summer period (June-Aug, left) and for the winter period (Dec-Feb, right) for the three future periods 2011-2040, 2041-2070 and 2071-2100 in the scenarios RCP4.5 and RCP8.5 are shown in Figure 3. The grey line shows the reference value for the present time (1981-2010). The expected temperature at the end of the century for RCP8.5 is 19.3°C (with an uncertainty range of 18.2 to 20.3) during summer, and 5.2°C (4.6 to 5.8°C) during winter.

 

Temperature and climate change figure 3

Figure 3 Future summer and winter temperatures
Source: Climate Atlas vers. 2 2020.

 

 

Read more and explore the data on Klimaatlas.dk (only available in Danish)

Senest redigeret: 03-02-2021