Download Mediterranean climate change scenarios: Impacts on the north

Mediterranean climate change scenarios:
Impacts on the north Adriatic coast
P.Lionello, University of Salento and CMCC, Lecce, Italy
With thanks to all speakers of the workshop organized by CoRiLa
“The climate in Venetia and the north Adriatic region: variability, trends and change”
Venice 23-25 Oct 2008
and particularly to
F.Antonioli, R. Böhm, F.Giorgi, M.Marcos, H.P.Plag, G.Spada,
M.Tsimplis for the material used in this presentation …
Venetia, Venice, North Adriatic
Cultural,
Environmental,
Economical
values at risk because of climate
change ?
Map of Venice in 16th century
Venetia, Venice, North Adriatic
Cultural,
Environmental,
Economical
values at risk because of climate
change ?
Venetia, Venice, North Adriatic
Cultural,
Environmental,
Economical
values at risk because of climate
change ?
The scales of climate
Global
Mediterranean
Italy
Northern Adriatic
Integration of expertise
•Historical climatology and past climate
•Northern Adriatic sea level and circulation:
variability and trends
•Land motions and relative sea level
•Storminess, waves and storm surge
•Regional climate change
A CHANGING COAST:
CHALLENGE FOR THE ENVIRONMENTAL POLICIES
November 25-28 2008 Venice Italy
Questions that should be answered :
* How would you rate the present level of knowledge?
* Is further research needed? Which specific research?
* Is the present climate condition well known?
* Are you in condition of providing a scenario of likely future
evolution?
* What is the basis for such projection?
* What is the level of uncertainty?
* How is it possible to reduce it with further research?
* Could you provide a likely range of values for the next
decades? For the end of the 21st century? (including most likely
and worse scenarios)
A CHANGING COAST:
CHALLENGE FOR THE ENVIRONMENTAL POLICIES
November 25-28 2008 Venice Italy
Temperature and precipitation:
present trends
A CHANGING COAST:
CHALLENGE FOR THE ENVIRONMENTAL POLICIES
November 25-28 2008 Venice Italy
The basis: HISTALP (Historical Instrumental Surface Timeseries
from the greater ALPine Region)
Auer I, Böhm R, Jurkovic A, Lipa W, Orlik A, Potzmann R, Schöner W, Ungersböck M, Matulla C, Briffa K, Jones PD, Efthymiadis D, Brunetti M, Nanni T,
Maugeri M, Mercalli L, Mestre O, Moisselin J-M, Begert M, Müller-Westermeier G, Kveton V, Bochnicek O, Stastny P, Lapin M, Szalai S, Szentimrey T, Cegnar
T, Dolinar M, Gajic-Capka M, Zaninovic K, Majstorovic Z, Nieplova E, 2007. HISTALP – Historical instrumental climatological surface time series of the greater
Alpine region 1760-2003. International Journal of Climatology 27: 17-46
Slide by R.Böhm
Slide by R.Böhm
IS GAR REPRESENTATIVE FOR VENETIA?
CORRELATION OF GAR-mean WITH WIDER EUROPE:
WINTER
TEMPERATURE
SUMMER
Efthymiadis D, Jones PD, Briffa K, Böhm R, Maugeri M, 2007. Influence of large-scale atmospheric circulation on climate variability in the
Greater Alpine Region of Europe. Journal of Geophysical Research 112: D12104, doi: 10.1029/2006JD008021
Also Venice highly correlated with GAR-mean
CORRELATION OF GAR-SE WITH WIDER EUROPE:
WINTER
PRECIPITATION
SUMMER
Efthymiadis D, Jones PD, Briffa K, Böhm R, Maugeri M, 2007. Influence of large-scale atmospheric circulation on climate variability in the
Greater Alpine Region of Europe. Journal of Geophysical Research 112: D12104, doi: 10.1029/2006JD008021
Also Venice highly correlated with SE-mean
Slide by R.Böhm
SEASONAL TM-TRENDS DIFFERENT AT DECADAL SCALE
SEASONAL HISTALP TEMP CRSM-LOW
°C
release 2008, s ingle yrs. and 20 years LP-filtered anomalies to 1901-2000
7
3
SUMMER HALFYEAR (AMJJAS) 1760-2007
2003: +2.8K
6
2
5
1
4
°C
0
3
-1
2
2006/7: +3.1K
1816: -2.0K
-2
1
-3
0
-4
-1
-5
-2
-6
-3
-7
WINTER HALFYEAR (ONDJFM) 1760/61-2007/08
1784/: +2.8K
-4
1760
1780
1800
-8
1820
1840
1860
1880
1900
1920
1940
1960
1980
2000
Matulla C, Auer I, Böhm R, Ungersböck M, Schöner W, Wagner S, Zorita E. 2005. Outstanding past
decadal-scale climate events in the Greater Alpine Region analysed by 250 years data and model runs.
GKSS-Report 2005/4 - updated
Slide by R.Böhm
SAME LONGTERM TM-TRENDS IN ALL SUBREGIONS
BUT REGIONAL WARMING TWICE AS STRONG AS GLOBAL
EI-corrected regional mean temperature series in the greater alpine Region :
ANNUAL MEANS 1760-2006
NW
GAR-all
SE
CRU-NH
SW
1
ca. 1°
ca.
2°
0
-1
2000
1980
1960
1940
1920
1900
1880
1860
1840
1820
1800
1780
-2
1760
anomalies from 1901-2000 (K)
NE
GAR-all
2
source: HISTALP T01-2007 LS-subset, EI-corrected and 30-years LP-f iltered
Slide by R.Böhm
4 +1 PRINCIPAL SUBREGIONS
CORRELATION TEMPERATURE
WINTER HALFYEAR (ONDJFM)
3
R2 = 0.93
2
NW
SUBREGION SE
NW
1
CORRELATION TEMPERATURE
SUMMER HALFYEAR (AMJJAS)
3
0
-1
-2
R2 = 0.85
2
HIGH
SUBREGION SE
1
-3
-2
-3
-1
0
VENEZIA
1
2
3
0
-1
-2
-3
-3
-2
-1
SW
0
VENEZIA
1
2
3
SE
Slide by R.Böhm
PRECIPITATION AND CLOUDINESS:
DIFFERENT SUBREGIONAL TRENDS („ALPINE DIPOLE“)
NW
NW
SW
SE
Slide by R.Böhm
208 YEARS OF PRECIPITATION IN VENICE:
Direct observations in Venice 1836-2005 blended with regional mean 1800-1835 and 2005-2007
mm
VENEZIA-CAVANIS PRECIPITATION SPRING (MAM) 1800-2007
single values and 20-yrs lp-filtered
600
500
mm
VENEZIA-CAVANIS PRECIPITATION SUMMER (JJA) 1800-2007
single values and 20-yrs lp-filtered
600
SPRING (MAM)
500
SUMMER (JJA)
400
400
300
300
200
200
100
100
0
1760 1780 1800 1820 1840 1860 1880 1900 1920 1940 1960 1980 2000
database: ZAMG-HISTALP version 2008
VENEZIA-CAVANIS PRECIPITATION AUTUMN (SON) 1800-2007
mm
single values and 20-yrs lp-filtered
600
0
1760 1780 1800 1820 1840 1860 1880 1900 1920 1940 1960 1980 2000
database: ZAMG-HISTALP version 2008
VENEZIA-CAVANIS PRECIPITATION WINTER (DJF) 1800-2007
mm
single values and 20-yrs lp-filtered
600
500
AUTUMN (SON)
500
400
400
300
300
200
200
100
100
0
1760 1780 1800 1820 1840 1860 1880 1900 1920 1940 1960 1980 2000
database: ZAMG-HISTALP version 2008
WINTER (DJF)
Slide by R.Böhm
0
1760 1780 1800 1820 1840 1860 1880 1900 1920 1940 1960 1980 2000
database: ZAMG-HISTALP version 2008
Are these present trends going to continue?
Temperature and precipitation in
climate change scenarios
A CHANGING COAST:
CHALLENGE FOR THE ENVIRONMENTAL POLICIES
November 25-28 2008 Venice Italy
title
Are models reliable?
A CHANGING COAST:
CHALLENGE FOR THE ENVIRONMENTAL POLICIES
November 25-28 2008 Venice Italy
From IPCC 4th AR
Figure TS.23. (a) Global mean surface
temperature anomalies relative to the
period 1901 to 1950, as observed (black
line) and as obtained from simulations
with both anthropogenic and natural
forcings. The thick red curve shows the
multi-model ensemble mean and the
thin lighter red curves show the
individual simulations. Vertical grey lines
indicate the timing of major volcanic
events. (b) As in (a), except that the
simulated global mean temperature
anomalies are for natural forcings only.
The thick blue curve shows the multimodel ensemble mean and the thin
lighter blue curves show individual
simulations. Each simulation was
sampled
so that coverage corresponds
Figure TS.23
to that of the observations. {Figure 9.5}
Model mean reliability
Temperature change (C, 2071-2100 minus 1961-1990),
MGME ensemble average, A1B scenario
DJF
MAM
JJA
SON
from Giorgi and Lionello, 2007
Precipitation change (%, 2071-2100 minus 1961-1990),
MGME ensemble average, A1B scenario
DJF
MAM
JJA
SON
from Giorgi and Lionello, 2007
(1981-2000) minus (1961-1980)
Precipitation change (%)
4
2
0
-2
Observed
MGME
-4
-6
-8
-10
Temperature change (C)
-12
0.8
0.7
0.6
0.5
Observed
MGME
0.4
0.3
Observed (CRU data) and MGME
ensemble average change in
precipitation (upper panel) and
surface air temperature (lower panel)
for the four seasons over the full
Mediterranean region (see Figure 1),
land only, 1981-2000 minus 19611980. Units are % of 1961-1980
value for precipitation and degrees C
for temperature
0.2
0.1
0
DJF
MAM
JJA
SON
from Giorgi and Lionello, 2007
Tmp-prec total
(2081-2100) minus (1961-1980)
Precipitation change (%)
0
-5
-10
B1
A1B
A2
-15
-20
-25
-30
-35
Temperature change (C)
6
5
4
B1
A1B
A2
3
2
MGME ensemble average change in
mean precipitation (upper panel)
and mean surface air temperature
(lower panel) for the full
Mediterranean region, the four
seasons and different scenario. The
changes are calculated between the
periods 2081-2100 and 1961-1980
and include only land points. Units
are % of 1961-1980 value for
precipitation and degrees C for
temperature
1
0
DJF
MAM
JJA
SON
from Giorgi and Lionello, 2007
MGME ensemble average, A1B scenario
Precipitation Change (%)
0
-5
2001-2020
2021-2040
2041-2060
2061-2080
2081-2100
-10
-15
-20
-25
Temperature change (C)
-30
5
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
2001-2020
2021-2040
2041-2060
2061-2080
2081-2100
DJF
MAM
JJA
SON
from Giorgi and Lionello, 2007
Precipitation change (%) as a function of time,
CMIP3 ensemble average, A1B scenario
DJF, 2020s-1970s
DJF, 2050s-1970s
DJF, 2080s-1970s
JJA, 2020s-1970s
JJA, 2050s-1970s
JJA, 2080s-1970s
title
Regional models
A CHANGING COAST:
CHALLENGE FOR THE ENVIRONMENTAL POLICIES
November 25-28 2008 Venice Italy
Temperature change (2071-2100 minus 1961-1990)
PRUDENCE ensemble, 8 RCMs, A2 Scenario
Winter (DJF)
Spring (MAM)
Summer (JJA)
Autumn (SON)
Slide by F.Giorgi
Precipitation change (2071-2100 minus 1961-1990)
PRUDENCE ensemble, 8 RCMs, A2 Scenario
Winter (DJF)
Spring (MAM)
Summer (JJA)
Autumn (SON)
Slide by F.Giorgi
Precipitation change (%)- dx=20 km
A2 (2071-2100) – Control (1961-1990) (Gao et al. 2005)
Slide by F.Giorgi
DJF
MAM
JJA
SON
Sea level: present trends
A CHANGING COAST:
CHALLENGE FOR THE ENVIRONMENTAL POLICIES
November 25-28 2008 Venice Italy
Marcos and Tsimplis, 2008
Slide by M.Tsimplis
Coastal sea level trends in the
Mediterranean
Sea level trends for the longest records
Marcos and Tsimplis, 2008
Sea level rise 1993-2007
Slide by M.Tsimplis
Vigo et al. 2005
Note the scales!
Figure 4. Linear rate-of-change map of: (a) SLA for Period I (cm year-1); (b) SLA for
Period II (cm year-1); (c) SST for the Period I (ºC year-1); (d) SST for Period II (ºC year-1Slide
).
by M.Tsimplis
Sea level trends
• Best estimate:
– Mediterranean sea level has been rising by
about 1.2 mm/yr
– Global sea level estimate 1.8 mm/yr
Conclusions
• Trends in the Mediterranean (based on Adriatic) 1.2
mm/yr ± 0.3 mm/yr over 90 years. Venice larger but
consistent with Trieste after 1960.
• During 1960-2000:
– Trends smaller ~0.5 mm/yr
– Pressure and wind responsible (-0.5 to -0.7 mm/yr)
– Steric trends also negative (but high range from -0.3 mm/yr to –
2.0 mm/yr)
– Externally to the Mediterranean forced about 1 mm/yr (after
1970)
– NAO wind and pressure variability can cause trends of ~0.5
mm/yr for 50 years of data- no such test for steric or other effects.
• Extremes changing in line with mean sea level
• We have lived in a stable environment – things will
probably change.
THE FUTURE
Local relative sea level trends result from
from vertical land motion (tectonic and other
geological and anthropogenic processes),
postglacial rebound (past mass changes),
present-day mass exchange, thermal
expansion, ocean and
atmospheric circulation changes.
A CHANGING COAST:
CHALLENGE FOR THE ENVIRONMENTAL POLICIES
November 25-28 2008 Venice Italy
-0.48
-0.49
-0.5
-0.58
-0.68
-0.54
-0.48
Tectonic rate
movement
(mm\years)
a – b / 125 ka
-0.69
-0.60
-1.09
-0.84
a = Present day
elevation of MIS 5.5
highstand deposits
b = MIS 5.5 eustatic
altitude (+6 m asl)
-1.06
-1.04
-1.06
slide by F.Antonioli
Slide by G.Spada
Conclusions & open problems:
i) The GIA signal is not constant across the Mediterranean: it significantly varies
from place to place- Giving a mean value is meaningless. Now the GIA rate of sea
level change can be estimated (with error bars) using public domain software
(SELEN 2) based on realistic models (see http://flocolleoni.free.fr/SELEN.html),
ii) Late holocene RSL data from the Mediterranean are useful to constrain the
chronology of remote ice sheets. ICE3G is ruled out. Evidence of catastrophic
rise events (CRE3) ~ 7 kyrs BP in the RSL data ?
iii) GIA produces a large-scale subsidence in the Mediterranean - At the tide gauge
of Genova and Trieste GIA accounts for a significant part of the observed rate of sea
level change signal (up to 30% of the total trend). Interestingly, quite (GIAunsensitive) places exist (e. g. Israel).
iv) In the NE Adriatic, GIA results from both far and near-field sources (ICE5G,
ALPS). ALPS counteracts ICE5G. The amount of sea level change driven by GIA
is (and will be in the next century) in the range of +/- 0.3 mm/yr (for “any” mantle
rheology). This is small (~ 10%) compared to the observed rate in Venice (close
to 2 mm/yr).
Slide 1
Emissioni di CO2 in atmosfera negli scenari SRES
(Nakicenovic et al, 2000). Le sigle identificano alcune
variabili che condizionano l’emissione di gas serra:
• A-B rispettivamente forte e ridotto fabbisogno
energetico;
• 1-2 rispettivamente sviluppo mondiale omogeneo e
eterogeneo.
The Steric Sea level: Methodology
1. Monthly T and S data
are extracted from the
global models
simulations of 21st
century climate
scenarios
2. Steric sea level is
computed for each grid
point as the vertical
integration of the specific
volume anomaly from
surface to bottom
0
1
η = ∫ αdp
g −H
Slide courtesy of M.Marcos
21st century projections
Salinity
T changes 0-2.5 ºC
S changes 0-2 psu
SRES A2
SRES A1B
Committed CC
Temperature
Slide courtesy of M.Marcos
21st century projections
Thermosteric
component
Committed CC
Halosteric
component
Halosteric sea level:
-70 to 20 cm
SRES A1B
Thermosteric sea level:
5 to 55 cm
SRES A2
35 cm
-25 cm
Slide courtesy of M.Marcos
Range of variation
-42 to 52 cm
-22 to 31 cm
SRES A2
SRES A1B
Committed CC
21st century projections
Slide courtesy of M.Marcos
Summary of the contributions to sea level rise by 2100 (in cm). The columns
marked with an asterisk are obtained from the global values provided by the
IPCC AR4 (2007).
Thermosteric
Halosteric
Steric
Atm.
Pressure
Mass
addition*
Equiv.
Volume
change*
Comitted CC
3 to 17
-8 to -27
-12 to 8
0.0
SRES A1B
19 to 52
-22 to -49
-22 to 18
-0.2
4-20
13-32
SRES A2
24 to 61
-23 to -55
-17 to 31
-0.6
4-20
14-35
Slide courtesy of M.Marcos
21st century projections
Spatial patterns of steric sea
level
Marcos and Tsimplis, 2008.
“Comparison of results of
AOGCMs in the Mediterranean
Sea during the 21st century”
JGR-Oceans in press
Slide courtesy of M.Marcos
21st century projections
The Adriatic Sea in the regional model
Change in steric sea level under
SRES A2
Slide courtesy of M.Marcos
Synthesis for steric effects…
• T and S projections for the 21st century predict warming and
salinification of the Mediterranean Sea in the 3 scenarios considered of
up to 2.5 ºC and 2 psu in average. Changes in the regional high
resolution model are smaller
• The effects on sea level are opposite. Thermosteric and halosteric
changes could compensate each other, thus keeping the steric sea level
component (average for the whole Mediterranean Sea) in the range -22
to +31
• It is necessary the development of high resolution regional models
describing different climate scenarios in order to improve future
estimates.
•It is necessary to properly account for the interaction with the Atlantic as
the Gibraltar Strait will play a key role in the future sea level
rise depending on how the Atlantic Ocean will evolve.
Mass contribution (based on IPCC 4th AR) is likely
in the range 4-20cm
But this is the greatest source of uncertainty…
And there is no consensus
A CHANGING COAST:
CHALLENGE FOR THE ENVIRONMENTAL POLICIES
November 25-28 2008 Venice Italy
Plausible Range of Future LSL
Plag and
Juettner
Vermeersen
et al.
Slide by HP Plag
Blue: 2050
Red: 2100
Green: 2200
Storminess … and “Aqua Alta” (storm surge)
A CHANGING COAST:
CHALLENGE FOR THE ENVIRONMENTAL POLICIES
November 25-28 2008 Venice Italy
RegCM experiment design
Giorgi, F., X. Bi and J.S. Pal , 2004 a and b
•
Global Model: Hadley Centre
HadAMH
•
•
•
– Dx = 1.25 lat x 1.875 lon
– SST from HadCM3 run
– Coupled sulfur model
Regional model: ICTP RegCM
– Dx = 50 km
– SST, GHG and sulfate from
HadAMH
– aerosol effects
Simulation periods
– 1961-1990 : Reference run
– 2071-2100 : Scenario run
Scenarios: A2, B2
CTR
B2
A2
Average monthly frequency (y-axis) of events exceeding
a fixed threshold (x-axis) in the scenario simulations.
The left panel considers the range 50-90 cm, the right
panel the range 90-120cm
Monthly max values
2-year return value
100-year return value
This figure compares monthly values
for the present climate (CTR) , A2 and
B2 scenarios. Top panel (a): monthly
maxima during the simulation, middle
panel (b): 2-year return time surge
levels, bottom panel (c): 20-year return
surge levels (Units=m., no
computation war carried out for the
period Jun-Sep). Values refer to the
CNR research station, located about
15km offshore in the Northern Adriatic.
Future projections suggest a lower
average level of the yearly highest
surge event, with a large reduction of
the corresponding 2-year return values
during Fall. However, the level of
extreme and potentially very
hazardous surge events (shown by
the 100-year return value) is projected
to increase in future scenarios during
November and February.
A CHANGING COAST:
CHALLENGE FOR THE ENVIRONMENTAL POLICIES
November 25-28 2008 Venice Italy
Beware: this study is based on single model simulations,
issues such as interdecadal variability and intermodel
variability cannot be addressed.
Results suggest a lower frequency of surge events in the
future climate scenarios but disastrous events may be,
marginally, more likely in future climate than in the present
one
A CHANGING COAST:
CHALLENGE FOR THE ENVIRONMENTAL POLICIES
November 25-28 2008 Venice Italy
Conclusions: temperature and
precipitation
• Present regional warming about twice as strong as
global
• Present small negative trend of cloudiness and
precipitation
• Projections include a progressive increase of
temperature and reduction of precipitation
• Values depends on models, scenarios, season, but
agree on a critical warming and precipitation reduction
during the warm season
• Average indicative values for the A1B scenario: 4K
warming in summer, and 30% reduction of summer
precipitation (controversial indications for winter)
Conclusions: sea level (part I)
• Trends in the Mediterranean (based on Adriatic) 1.2
mm/yr ± 0.3 mm/ yr over the period 1920-2007 (global
value for the same period 1.8cm )
• Trends in extremes due to relative SLR, not to increase
of storminess
Conclusions: sea level (part II)
• Local Sea rise results from from vertical land motion
(tectonic, geological and anthropogenic processes),
postglacial rebound, present-day mass exchange,
thermal expansion, ocean and atmospheric circulation
changes.
• Sea level change driven by Tectonic is 0.6-07mm/year,
driven by GIA is about -0.1 (negative) and in the range of
+/- 0.3 mm/yr
• Halosteric and thermosteric effects have opposite sign
and are likely to provide a change of sea level in the
range -22 to +31 cm by the end of the century
• IPCC 4th AR suggest that mass contribution is likely in
the range 4-20cm, but there is a large uncertainty and
this value might be a substantial underestimate
• Change in storminess likely play a minor role
Questions that should be answered :
* How would you rate the present level of knowledge?
* Is further research needed? Which specific research?
* Is the present climate condition well known?
* Are you in condition of providing a scenario of likely future
evolution?
* What is the basis for such projection?
* What is the level of uncertainty?
* How is it possible to reduce it with further research?
* Could you provide a likely range of values for the next
decades? For the end of the 21st century? (including worse
scenarios)
A CHANGING COAST:
CHALLENGE FOR THE ENVIRONMENTAL POLICIES
November 25-28 2008 Venice Italy
ONE OF 100 QUESTIONS OF A RECENTLY PUBLISHED
REVIEW OF A SAMPLE OF >500 CLIMATOLOGISTS
Bray D and von Storch H, 2007. The Perspectives of Climate Scientists
on Global Climate Change. GKSS 2007/11
Bray D and von Storch H, 2007. The Perspectives of Climate Scientists
on Global Climate Change. GKSS 2007/11
Mediterranean climate change scenarios:
Impacts on the north Adriatic coast
… A lot of progress has been reached in climate science and
there is a lot of available useful information … However,
presently, dealing with uncertainty and controversial quantitative
analysis of future cliamte scenarios is part of the business
Mediterranean climate change scenarios:
Impacts on the north Adriatic coast
P.Lionello, [email protected]
With contribution by
F.Antonioli, R. Böhm, F.Giorgi, M.Marcos, H.P.Plag, G.Spada,
M.Tsimplis
The end … Thanks for your attention