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Helge DrangeGeophysical InstituteUniversity of Bergen
www.bjerknes.uib.no
Helge [email protected]
Observed and projected climate change –from global to local scale
Helge DrangeGeofysisk institutt
Universitetet i Bergen
CO
2 (p
art
s p
er
mill
ion
)CO2 in air (from Mauna Loa, Hawaii)
Helge DrangeGeofysisk institutt
Universitetet i Bergen
Helge DrangeGeofysisk institutt
Universitetet i Bergen
2008
Helge DrangeGeofysisk institutt
Universitetet i Bergen
2009
Helge DrangeGeofysisk institutt
Universitetet i Bergen
2010
Helge DrangeGeofysisk institutt
Universitetet i Bergen
2011
Helge DrangeGeofysisk institutt
Universitetet i Bergen
2012
Helge DrangeGeofysisk institutt
Universitetet i Bergen
1912
Helge DrangeGeofysisk institutt
Universitetet i Bergen Ch
urc
h e
t al
(20
11)
Ch
ang
e in
hea
t (1
022 J
)Change in heat content of ocean & land+atm+ice
Helge DrangeGeofysisk institutt
Universitetet i Bergen Ch
urc
h e
t al
(20
11)
Change in heat content of ocean & land+atm+iceC
han
ge
in h
eat
(102
2 J
)
Helge DrangeGeofysisk institutt
Universitetet i Bergen
Earth´s climate is Earth´s climate is changingchanging
Main reason is our use of Main reason is our use of coal, oil and gascoal, oil and gas
Helge DrangeGeophysical instituteUniversity of Bergen
Possible futurePossible future
uncertainty ≠ no certainty
Helge DrangeGeofysisk institutt
Universitetet i Bergen
Change in global temperature, 15 models(relative to 1961-1990)
Helge DrangeGeofysisk institutt
Universitetet i Bergen
Future emissions as today (“Business-as-usual”)
+2 °C 2025-2050
Change in global temperature, 15 models(relative to 1961-1990)
In 2100:Global: 4.0-5.8 °CLand: 5.0-8.5 °C
Helge DrangeGeofysisk institutt
Universitetet i Bergen
Global emission top in 2040, 650 ppm CO2-eq in 2100
+2 °C 2035-2075
Change in global temperature, 15 models(relative to 1961-1990)
For a global, mean warming of ~2 °C, which we can expect sometime during second half of the 21st century, Earth's climate is comparable to
the climate ~3.2 mill years ago
In 2100:Global: 2.0-3.0 °CLand: 2.1-4.8 °C
Helge DrangeGeofysisk institutt
Universitetet i Bergen
Drought index based on 14 climate models(2090-2099; RCP4.5)
Dai, Nature Clim. Change (2012)
Severe to extreme drought
Incr soil moisture
Helge DrangeGeofysisk institutt
Universitetet i Bergen
Over to local scaleOver to local scale(where we all live)(where we all live)
Much harder to do local than continental/global climate projections!
Harder to make projections of precipitation than temperature
Very hard to make projections about local changes in extremes
Helge DrangeGeophysical InstituteUniversity of Bergen
Helge DrangeGeophysical InstituteUniversity of Bergen
Helge DrangeGeophysical InstituteUniversity of Bergen
Helge DrangeGeophysical InstituteUniversity of Bergen
Helge DrangeGeofysisk institutt
Universitetet i Bergen
Western Norway, 14 September 2005
Helge DrangeGeofysisk institutt
Universitetet i Bergen
Helge DrangeGeofysisk institutt
Universitetet i Bergen
14 Sep 2005
For Bergen: +30 to +70 %
increase in extreme precipitation by the end
of the century
Helge DrangeGeofysisk institutt
Universitetet i Bergen
Photo: Jan M. Lillebø, Bergens Tidende
Sea level
Helge DrangeGeofysisk institutt
Universitetet i Bergen
Warming of the oceanMay contribute 15-20 cm in this
century
Glaciers meltingMay contribute 15-20 cm in this
century
Greenland and AntarcticaMay contribute 10-40 cm in this
century (large uncertainties)
Total:+40 to +80 cm in 2100Cont’d increase “forever”
Department of GeophysicsUniversity of Bergen
Drange m.fl. (2012)
Estimated sea level rise (cm) along the coast of Norway, next 100 years
(corresponding to a global sea level rise of 50-110 cm)
About 1/3 of this rise by 2050
Department of GeophysicsUniversity of Bergen
Sea levelWill last for > 1000 yr
Department of GeophysicsUniversity of Bergen
2-degree target2-degree target
Helge DrangeGeofysisk institutt
Universitetet i Bergen
2-degree target:Consequence of delaying cuts in CO2-emissions
(i) CO2-emissions from coal, oil and gas, 1950-2012
Glo
bal
CO
2-em
issi
on
s (G
t-C
)
Meinshausen et al. (2009), updated
Helge DrangeGeofysisk institutt
Universitetet i Bergen
2-degree target:Consequence of delaying cuts in CO2-emissions
(ii) Reduced CO2-emissions from 2013
Meinshausen et al. (2009), updated
Glo
bal
CO
2-em
issi
on
s (G
t-C
) 2013: − 7 % / yr
Helge DrangeGeofysisk institutt
Universitetet i Bergen
2-degree target:Consequence of delaying cuts in CO2-emissions
(iii) Reduced CO2-emissions from 2017
Meinshausen et al. (2009), updated
Glo
bal
CO
2-em
issi
on
s (G
t-C
)
2017: −11 % / yr
2013: − 7 % / yr
Helge DrangeGeofysisk institutt
Universitetet i Bergen
2-degree target:Consequence of delaying cuts in CO2-emissions
(iv) Reduced CO2-emissions from 2021
Meinshausen et al. (2009), updated
Glo
bal
CO
2-em
issi
on
s (G
t-C
)
2021: −22 % / yr
2017: −11 % / yr
2013: − 7 % / yr
Helge DrangeGeofysisk institutt
Universitetet i Bergen
??
2-degree target:Consequence of delaying cuts in CO2-emissions
(v) Reduced CO2-emissions from 2025
Glo
bal
CO
2-em
issi
on
s (G
t-C
)
Meinshausen et al. (2009), updated
2025: −90 % / yr
2021: −22 % / yr
2017: −11 % / yr
2013: − 7 % / yr
Helge DrangeGeofysisk institutt
Universitetet i Bergen
About 20 percentAbout 20 percentof today's COof today's CO22-emissions will -emissions will
remain in the atmosphere remain in the atmosphere for 1000 years or morefor 1000 years or more
Helge DrangeGeofysisk institutt
Universitetet i Bergen
Earthrise, 24 Dec 1968(credit: NASA)
Slides and animations available from