Climate change impacts and vulnerability in Europe 2016

Climate change impacts on environmental systems
Figure 4.3
Global ocean heat content at different depths
10 22 Joules
25
20
15
10
5
0
– 5
– 10
– 15
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
2015
Source:
0–700 m 5-year average 0–700 m yearly average 0–2 000 m 5-year average 0–2 000 m yearly average
Data produced by NOAA's National Centers for Environmental Information (NCEI) (formerly the National Oceanographic Data Center
(NODC)).
Projections
All available ocean temperature projections suggest
that the global ocean will continue to warm. The
largest warming is projected for the upper few
hundred metres of the sub-tropical gyres, similar to
the observed pattern of ocean temperature changes.
Mixing and advection processes will gradually transfer
the additional heat to deeper levels.
The rate of increase of OHC is approximately
proportional to the global mean change in surface
air temperature. Under the low-to-medium (RCP4.5)
emissions scenario, half of the energy taken up
by the ocean by the end of the 21st century will
be by the uppermost 700 m, and 85 % will be by
the uppermost 2 000 m. Projected ocean warming
varies considerably across forcing scenarios.
Globally averaged projected surface warming ranges
from about 1 °C for RCP2.6 to more than 3 °C for
RCP8.5 during the 21st century, and at a depth of
1 000 m ranges from 0.5 °C for RCP2.6 to 1.5 °C for
RCP8.5 (Taylor et al., 2012; Church et al., 2013; Collins
et al., 2013; Kirtman et al., 2013).
112 Climate change, impacts and vulnerability in Europe 2016 | An indicator-based report