impatti dei cambiamenti climatici sugli ecosistemi marini

CENTRO EURO-MEDITERRANEO

PER I CAMBIAMENTI CLIMATICI

Impatti dei cambiamenticlimatici sugli ecosistemi

marini: dall'oceano globale almare Mediterraneo

Marcello Vichi

[email protected]: Operational Oceanography Group (GNOO)

INGV Bologna; EU projects SESAME, MERSEA,

BOSS4GMES; Italian project VECTOR



Outline

! The global ocean ecosystem and climate

! Global climate change scenarios and

downscaling to the Mediterranean

! Anticipated impacts on the ecosystems

! On-going projects



The ocean carbon cycle

Biological pump Solubility pump



A sea of interactions…Encyclopedia of the Earth

<http://www.eoearth.org/article/Marine_microbial_loop>



What controlsPrimary Production in the sea

! Light

! Nutrients

! Trophic interactions

All this factors are affected by the general

circulation of the ocean:

underlying assumption that coherent biological

properties are a direct (or modulated) response to

physicsBiogeography



Ocean biogeography

Satellite data (1997-2005)

Chlorophyll and vegetation index

http://oceancolor.gsfc.nasa.gov

Surface ocean currents

http://commons.wikimedia.org

Surface nitrate concentration

WOA01 (Conkright et al., 2002)



Change and causality

! How do we define changes?

! Climate change: a modification of the mean orvariance of climate variables over a sufficiently longperiod (~30 years)

! Ecosystem change: a modification of salientfeatures (such as keystone species) which “may”lead to a change in the ecosystem structure and theability to provide goods and services

! It is more difficult than we thought! (Caddy andSeijo, 2005)

! Surprises are around the corner (Doek et al., 2008)



Detecting changes inmarine ecosystems! Marine biogeography is the

classification of oceanic regions

either based on the presence of

key species (e.g. copepods) or on

the determination of coherent

physical properties which defines a

biome or a province (sensu

Longhurst, 2007)

! Changes in biogeographic

provinces can thus be related to

climate change

! CPR zooplankton data (Beugrand

et al., 2002; picture from

Richardson, 2008)

Zooplankton abundance



Sea-use change

Nutrients Organic pollutants

Inorganic pollutants Direct human impact

Shipping (pollution)



The Mediterraneanperspective



A multi-scale system

http://gnoo.bo.ingv.it/mfs

Mean Daily Surface Temperature analysis (degC) since 2008-01-01



Simulated at finer resolutions

http://gnoo.bo.ingv.it/afs

Daily forecasts of the Adriatic sea

oceanographic parameters with a 2

km spatial resolution model



An oligotrophic sea

SeaWiFS satellite ocean color data (1998-2003)Barale et al., 2005



First attempts at environmentalpredictions

7 days forecast with the Biogeochemical Flux Model (http://bfm.cmcc.it) and

forced with MFS forecast data



A 2oC warming scenario

! Ecosystem changes with new invasive ornon-native species such as gelatinouszooplankton and medusa, toxic algal blooms,increased fouling and decreased dissolvedoxygen events, will increase operation costs..

! In terms of biodiversity, climate change islikely to lead to shifts in the distributions andabundances of species, potentially increasingthe risks of extinction.

Giannakopoulos et al., WWF report 2005

Alcamo et al., Chapter 12 IPCC AR4 WG 2, 2007



The uncertainty cascade

Adapted from IPCC 2001

Emission

scenarios

Carbon cycle

response

Global climate

sensitivity

Regional climate

change scenarios

Range of possible

impacts



Djurdjevic et al., Belgrade University

(pers. comm.)

Downscaling of global climate models



Surface Temperature mean differences 2071:2100 - 1971:2000

(INGV-SXG climate model: Gualdi et al., 2008; Scoccimarro et al., 2007)

A1B A2

DJF

JJA

Scenario projections (1)



Scenario projections (2)

Projected changes in mixed layer depth (m)

[Somot et al., Climate Dynamics, 2006]

Control (current climate) Scenario (A2)

Simulated changes in mean SST from the

INGV-SXG model

[Gualdi et al., 2008; Scoccimarro et al., 2007]

compared with observed changes

[Reynolds et al., 2002]



What about the impacts onSES ecosystems?



Observed changes in the NA

Tedesco et al., Biogeosciences, 2007

Chl timeseries 1986-2005

The Cox-Stuart test for

long-term trends detected

significant trends only for

observed temperature

and salinity (connected

partly to large scale,

climatic signals) but NOT

for chlorophyll



Changes in dominant modes

D’Ortenzio et al., 2003

2000

The Eastern Mediterranean Transient wasan event in the ‘90s that changed the deepwater circulation of the basin.It apparently had little effects on the upperproductive layers of the EM, though somemacroscopic features did change(Calabrian Bloom, Rhodes Gyre Bloom)

CZCS Chl SeaWiFS Chl

Heat flux (NCEP)



A model ecosystem response

Vichi et al., Climate Research, 2003

Main assumptions:

(1) The CO2 pool in

the marine system is

an infinite source;

(2) The river

influence (runoff and

nutrient inputs) is as

in present days

Usage of a

comprehensive

biogeochemistry model

(early version of the

BFM

http://bfm.bo.ingv.it)



Projections

Surface chlorophyll

Surface GPP Surface DOC

SST



What do we need to improvethe impact studies?



Improved regional climate scenarios

http://www.bo.ingv.it/circeip

to develop for the first time an integrated assessment of the climatechange impacts in the Mediterranean area• To predict and to quantify physical impacts of climate change in theMediterranean area• To evaluate the consequences of climate change for the society and theeconomy of the populations located in the Mediterranean area.• To develop an integrated approach to understand combined effects ofclimate change.• To identify adaptation and mitigation strategies in collaboration withregional stakeholders.

Coordinators: A. Navarra (CMCC-INGV), L. Tubiana (IDDRI)



http://www. sesame-ip.eu

Coordinator: E. Papathanassiou,HCMR, Greece

1. To assess the changes or regime shifts in the ecosystems of theSouthern European Seas (Mediterranean and the Black Sea - SES)over the last 50 years and

assess the potential mechanisms that relate these changes to changesin natural and anthropogenic forcings.

2. To assess the current status of the SES ecosystems through analysis of

existing and newly collected data as well as through model simulations.

3. To predict changes in the SES ecosystem responses to likely changes

in climate and anthropogenic forcings during the next five decades.

4. To assess and predict changes in the ability of the ecosystems toprovide goods and services (with potentially high societal importance).

• Goods: tourism and fisheries• Services: ecosystem stability through conservation of

biodiversity, and mitigation of climate change through carbon

sequestration in waters and sediments



SESAME applications

The five study areas over which the semi-

quantitative fields of economics and social sciences

will be fully addressed.



The Italian project VECTOR

Coordinator: C. CorselliCONISMA, Italy

Assess the vulnerability of Italian coastlines andMediterranean marine ecosystems to climate changesin the context of a changing Earth System.

" case studies" long-term Eulerian monitoring" seasonal transects" trans-Mediterranean cruise" regional and global models

http://vector-conisma.geo.unimib.it



Take-home message

! The definition of “regional climate” of climate scientists isdifferent from the one of field experimentalists (!). Climatechange projection impacts have to be carefully interpreted atthe proper scales

! Global warming scenarios are likely to impact vulnerableecosystems. Changes in biodiversity and ecosystem structuremay not be simple to detect (and foreseen!)

! Coastal areas will require longer timeseries to capturepossible changes due to the higher intrinsic variability

! Models (conceptual and numerical) are keys to assess theimpacts of climate change on marine ecosystems

! More adequate climate products for impact assessments willbe available soon

impatti dei cambiamenti climatici sugli ecosistemi marini

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