Climate change impacts and vulnerability in Europe 2016

Changes in the climate system
Figure 3.2 Atmospheric CO 2 concentrations for the last 800 000 years and since 1959
CO 2
concentration in the atmosphere in the last 800 000 years
Parts per million
(ppm) of CO 2
450
400
350
300
250
200
150
Parts per million
(ppm) of CO 2
450
400
350
300
250
200
150
CO 2
concentration in the atmosphere since 1959
100
50
0
– 800 000
– 700 000
– 600 000
– 500 000
– 400 000
– 300 000
– 200 000
EPICA Dome C and Vostok Station, Antarctica
Law Dome, Antarctica (75-year smoothed)
Siple Station, Antarctica
Mauna Loa, Hawaii
– 100 000
0
Year
Barrow, Alaska
100
50
Cape Matatula, American Samoa
0
South Pole, Antarctica
Cape Grim, Australia
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
2015
Lampedusa Island, Italy
Shetland Islands, Scotland
Note:
The CO 2 concentration until 1955 is estimated from ice-core or deep-sea sediment data. Concentrations from 1959 are obtained from
instrumental measurements from eight different measurement stations.
Source: Luthi et al., 2008; US EPA, 2015.
3.1.3 Observed climate change and its attribution to
specific causes
Since the 1850s, almost the entire land and sea
surface has warmed, although not uniformly, as land
areas show more warming than oceans. According
to the World Meteorological Organization (WMO),
2015 was the warmest year on record, which 'broke
all previous records by a strikingly wide margin'
(WMO, 2016). The total increase in global average
land and ocean near-surface temperature in 2015 was
around 1 °C compared with the pre-industrial period
(see Section 3.2.2 for details). Increased temperatures
have led to the melting of the Greenland ice sheet,
Arctic sea ice, mountain glaciers and snow cover,
which are all declining rapidly (see Section 3.3 for
details). Observations also show increases in ocean
heat content in the deeper ocean (i.e. between 700 and
2 000 m and below 3 000 m) and increases in sea level
(see Sections 4.1 and 4.2 for details). Changes in global
precipitation since 1900 display both positive and
negative trends, but there are many areas that lack
robust long-term measurements (IPCC, 2013a).
In Europe, 2014 and 2015 were the warmest years
on record (EURO4M, 2016) (see Section 3.2.2).
Furthermore, reconstructions show that summer
temperatures in Europe in recent decades are the
warmest for at least 2 000 years, and that they lie
significantly outside the range of natural variability
(Luterbacher et al., 2016). Several independent analyses
have concluded that, in relation to the 2014 Europe
temperature record, 98 % of the temperature increase
can be attributed to anthropogenic climate change,
which made this record 35–80 times more likely
(EURO4M, 2015; Kam et al., 2015).
Observations of climate variables are made from
measurements taken in situ (land and sea surface,
atmosphere and deep ocean), as well as remote
measurements made by satellites, lidars and
radars. Global-scale observations date back to the
mid‐19th century, with independent, comprehensive
and sustained datasets available since the 1950s.
Globally and within Europe, some regions have
shorter data records than others and, even within
Europe, not all data from weather stations are shared
freely (Map 3.1). As a result, there are large data
gaps, even in interpolated datasets (Donat et al.,
2013; Zwiers et al., 2013). In regions where many
stations with long records are available to all users,
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