Climate change impacts and vulnerability in Europe 2016

Climate change impacts on society
occurred in southern Europe (latitudes below 45 °N),
where the energy demand for cooling in summer is
highest (Map 5.17, right panel).
The relative increase in CDDs is much higher than the
relative decrease in HDDs, because of lower absolute
values. In principle, HDD and CDD values can be
added together to give a new indicator, energy degree
days, which has shown a decrease since the 1950s.
However, one must consider that HDDs and CDDs are
climatological parameters and that the energy demand
linked to their values is not the same, as heating
and cooling systems are often based on different
technologies.
Figure 5.8 highlights some important features of the
evolution of the pattern of HDDs and CDDs in Europe
since the 1950s. In the first three decades, HDDs were
roughly constant and CDDs declined slightly. Since the
beginning of the 1980s, Europe has started experiencing
a markedly declining overall trend in HDDs, and a
markedly increasing trend in CDDs, pointing to a general
increase in cooling needs and a general decrease in
heating needs. Map 5.17 shows that the decrease in
HDDs has been particularly strong in the Alpine areas
and the Baltic and Scandinavian countries, whereas
the increase in CDDs is particularly strong in southern
Europe, around the Mediterranean and in the Balkan
countries. Some overlapping of medium to strong HDD
and CDD effects is noticeable in Bulgaria, southern
France, Italy, Portugal, Romania and Spain.
Projections
Temperatures in Europe are projected to continue to
increase. Hence, the trend of a decreasing number of
HDDs and an increasing number of CDDs is very likely
to continue, and most likely to accelerate (Benestad,
2008). Model simulations performed in the ClimateCost
project (based on HDD and CDD data) have estimated
the decrease in residential heating energy demand
in the EU as a result of climate change alone (above
the SRES A1B baseline without climate change) to be
28 million tonnes of oil equivalent (Mtoe)/year by 2050
and 65 Mtoe/year by 2100; the corresponding projected
increase in cooling energy demand is 16 Mtoe/year by
2050 and 53 Mtoe/year by 2100. While the projected
physical energy reductions for heating are higher than
the increase in cooling demand, in economic terms
the projected reduction in total heating demand is
about the same as the increase in cooling demand,
as cooling is more expensive than heating. In cold
countries, such as Norway, the net effect of projected
temperature increases reduces total energy demand,
whereas in warm countries, such as Spain, it increases
energy demand. All projected changes are considerably
lower under a mitigation scenario with lower emissions
(Mima and Criqui, 2015).
Figure 5.8
Time series of population-weighted heating and cooling degree days averaged over Europe
Heating degree days (HDD)
Cooling degree days (CDD)
2 900
2 700
2 500
2 300
2 100
1 900
1 700
1 500
1950
1960
1970
1980
1990
2000
2010
200
180
160
140
120
100
80
60
40
20
0
1950
1960
1970
1980
1990
2000
2010
Weighted HDD 1951–2014 Trend 1951–2014
Weighted CDD 1951–2014 Trend 1951–2014
Note:
Source:
This figure shows time series of heating degree days (left) and cooling degree days (right) averaged over Europe (EU-28 without Cyprus
but including Liechtenstein, Norway and Switzerland) over the period 1951–2014, including linear trends for 1951–1980 and 1981–2014.
Population weighting was applied during spatial aggregation.
JRC, KNMI-ECA&D (E-OBS version 11) and Eurostat GEOSTAT 2011 dataset.
Climate change, impacts and vulnerability in Europe 2016 | An indicator-based report
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