Present trends and climate change projections for the Mediterranean region

Present trends and climate change projections for the Mediterranean region Prof. Piero Lionello, piero.lionello@unile.it Science of Materials Department, University of Salento, Italy

Plan of the talk: An introduction to the climate of the Mediterranean region. Present trends of precipitation and temperature Climate projections for the Mediterranean region Water scarcity Other factors

1700km 3700km

10 out of 30 Köppen climate types are present around the Mediterranean Sea

Past winter precipitation (DJF) Luterbacher J. et al. (2005), Mediterranean climate variability over the last centuries: a review In P.Lionello, P.Malanotte-Rizzoli, R.Boscolo (eds) Mediterranean Climate Variability. Amsterdam: Elsevier (NETHERLANDS).

Graphics based on CRU (Climatic Research Unit) climatology, interpolated from station data to 0.5 degree lat/lon grid ( New, M., M. Hulme and P. Jones, 1999a and b) http://www.cru.uea.ac.uk/cru/

Temperature 1975-2000 DJF MAM JJA SON

Precipitation 1975-2000 DJF MAM JJA SON Pre_season_19 75_2000

Present trends of precipitation and temperature

Temperature trend 1975-2000 DJF MAM JJA SON

Precipitation trends 1975-2000 DJF MAM JJA SON

Wet season precipitation trend (1950-1999) Acknowledgement: Xoplaki, 2002; Xoplaki et al., 2004 mm/50years

ECA&D: EUROPEAN CLIMATE ASSESSMENT & DATASET http://eca.knmi.nl/index.php Participants and data Today, ECA&D has 53 participants from 41 countries and the ECA dataset contains 7033 series of observations at 2317 meteorological stations throughout Europe and the Mediterranean (see Daily data > Data dictionary for an overview of all available series). Participation to ECA&D is open to anyone maintaining daily station data. If you want to join please contact us.

Though there is a possibly widespread over-perception of precipitation trends, reduction of (winter) precipitation is observed over large areas of the Mediterranean region. The signal for temperature is much clearer than for precipitation: there is positive trend with an acceleration during the last part of the 20th century involving the whole Mediterranean region. Clear positive trend of heat waves, less clear trend for a more extreme precipitation regime In general, it is important to increase the number of long time series Risoluzione 5

MODEL Grid interval 20C B1 A1B A2 CCMA-3-T47 CNRM-CM3 CSIRO-MK3 GFDL-CM2-0 GFDL-CM2-1 GISS-AOM GISS-E-R INMCM3 IPSL-CM4 MIROC3-2H MIROC3-2M MIUB-ECHO-G MPI-ECHAM5 MRI-CGCM2 NCAR-CCSM3 NCAR-PCM1 UKMO-HADCM3 ~2.7 deg ~2.8 deg ~2.3 deg ~2.2 deg ~2.2 deg ~3.5 deg ~4.5 deg ~4.5 deg ~3.0 deg ~1.2 deg ~2.8 deg ~3.2 deg ~2.3 deg ~2.8 deg ~1.4 deg ~2.8 deg ~3.0 deg 5 4 4 2 1 1 1 1 2 1 1 1 3 1 1 1 3 0 1 1 2 2 2 0 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 0 3 3 3 3 5 3 3 3 3 3 2 3 5 5 5 5 8 8 6 4 4 2 3 4 1 1 1 1 List of models, grid interval (atmosphere) and experiments used in this work. 20C indicates experiments for the 20c century, B1, A1B and A2, experiments for the 21st century under forcing deriving from the corresponding IPCC emission scenarios. The grid interval is approximate, as it may vary across latitudes and may be different in the longitude and latitude directions. More detailed information on models and experiments is available the PCMDI web site http://wwwpcmdi.llnl.gov for.

Precipitation change (%) Temperature change (C) 4 (1981-2000) minus (1961-1980) 2 0-2 Observed -4 MGME -6-8 -10-12 0.8 0.7 0.6 0.5 Observed 0.4 MGME 0.3 0.2 0.1 0 DJF MAM JJA SON 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 (land only) 1981-2000 minus 1961-1980. Units are % of 1961-1980 value for precipitation and degrees C for temperature. from Giorgi and Lionello, 2007

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

0 Evolution in time of precipitation (upper panel) and temperature (lower panel) Precipitation Change (%) -5-10 -15-20 -25 2001-2020 2021-2040 2041-2060 2061-2080 2081-2100 -30 MGME ensemble average, A1B scenario Temperature change (C) 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

JJA temperature anomalies (relative to 1961-1990) Black lines: observations, Coloured lines: models Human contribution to the European heatwave of 2003 Stott, Stone & Allen, Nature, Dec. 2004

5 degs Risoluzione 5

4 degs Risoluzione 4

3 degs Risoluzione 3

2 degs Risoluzione 2

1 degs Risoluzione 1

0.5 degs Risoluzionem 0.5

0.2 degs Risoluzione 0.2

0.1 degs Risoluzione 0.1

From Zampieri et al. 2009 DJF JJA

From Zampieri et al. 2009 DJF JJA

Precipitation annual cycle of monthly means averaged over the Northern Adriatic region. Different lines correspond to CRU data in red color for period 1961-1990, to CTR ensemble mean, in green, computed for period 1961-1990 over the PRUDENCE, ENSEMBLES and SMHI data, to SCN-A2 ensemble mean, in blue, computed for period 2071-2100 over the PRUDENCE data, and to SCNA1B and scn-a1b, in violet for period 2071-2100 and light blues for period 2021-2050, respectively, computed over ENSEMBLES and SMHI data. From Zampieri et al. 2009

From Giorgi,, GRL, 2006

Large warming (very likely) and reduced precipitation (likely, with rather large spatial variability) are the projected consequence of anthropogenic climate change in large parts of the Mediterranean (including Middle east) Models are not flawless. Regionalization is important for the Mediterranean area.

Future water availability Milly et al 2005 A1B scenario, mid 21st century relative to 1900-1970 12 GCMs, hatched > 90% agreement

Mediterranean ecosystems have been strongly modified 14.000 years of sheap breeding 11.000 years of wheat cultivation 8.000 yrs of olive/fruit trees Palestine 200 A.D. > 5 million people Le Houérou 1981 Slide courtesy of H.Hoff MEA 2005

25000 Population in the Middle East and Northern Africa 20000 15000 10000 5000 Cyprus Gaza Strip Israel Lebanon Syria 0 1955 1 1970 2 1985 3 2000 4 2015 5 2030 6 70000 60000 50000 40000 30000 20000 Algeria Egypt Libya Morocco Tunisia 10000 0 1955 1 1970 2 1985 3 2000 4 2015 5 2030 6

urban population: 44% in 1950, 64% in 2000, 74% in 2025

Conclusions The geographic Mediterranean region is climatically inhomogeneous and characterized by a strong time variability There is a clear warming signal, affecting also extreme indicators. Precipitation trends are an issue (they appear not so robust as for temperature, there is a data problem) Climate projections in the Mediterranean region need high space resolution. Capability of models to reproduce present climate patterns and trends are not adequate, especially for precipitation Models agree that the Mediterranean region is a hot spot for climate change: Large warming and strong precipitation decrease are projected by most models Water scarcity is a major issue that, if not properly managed, might become dramatic in future Societal factors are at least as important as (likely more than ) climate change physical drivers for availability of future water resources