bssc 2011 st. petersburg, 26 august 2011

BSSC 2011 St. Petersburg, 26 August 2011

Regional Climate Change Assessments as a Service to Society: The BACC Example

Marcus Reckermann

Hans-Jörg Isemer

Hans von Storch

Anders Omstedt

and the BACC Author Team

www.baltex-research.eu

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August 2011 2

Overview

1. Examples and principles for BACC-type assessments

2. BACC results (published 2008)

3. BACC 2



Why regional climate change assessments?

Why care about regional climate change?

• Global assessment done by IPCC (AR4 from 2007)

• Climate changes NOT uniformly around the world

• Impacts differ greatly around the world

• Relevant political decisions are taken locally (adaptation)

• Public and policy makers need scientifc information

• Information scattered in numerous publications, largely difficult to access (language), let alone for non-scientists

→ Regional Climate Offices

→ Regional Climate Change Assessments



BACC-like assessments

BACC II (2009-2013)

NOSCCA North Sea Region Climate Change Assessment (2010-2014)

2

BACC (2005-2008)

Climate Report for the Metropolitan Region of Hamburg (2007-2010)



BACC Science Steering Committee

Contributing authors

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Expert review

1st draft

Publication

selects

2nd draft

Final draft

Expert review

Draft chapter outlines and select

Lead authors

BALTEX Science Steering Group and Scientific community

Editing and Formatting

Organisation

The BACC process

Similar to IPCC process but no government review

Strictly scientific



Principles…

• Writing team of experts from different expertises, lead authors responsible for grand topics (IPCC-style)Lead authors recruit contributing authors with special expertise

• Exclusive use of „current legitimate knowledge“… What is that?- published and publicly available- peer reviewed articles from scientific journals- institutional reports- conference proceedings- No NGO or private company publications (e.g. Greenpeace, WWF, Shell, Munich-Re etc.)- No unpublished results

• Objectivity: No mixing of personal views, agendas or missions to be mixed up with the scientific status; consensus view to be reached if possible

• If consensus cannot be reached, this must be stated („we agree that we disagree“), and conflicting views should be described

• Minority views should not be ignored if they are scientifically plausible

Principles of BACC-like assessments



BALTEX Assessment of Climate Change for the Baltic Sea basin - BACC

BACCground • Regional climate change assessments needed (IPCC has been doing global

climate change assessments since 1990)• Vast amount of material available in the Baltic Sea basin (also partly inaccessible

previousely).

Purpose • to provide the scientific community (and the public) with an assessment of

ongoing and future climate change in the Baltic Sea Basin• is done by reviewing and assessing published scientific knowledge on climate

change in the Basin

84 authors from 13 countries contributed > 2000 references, ~ 10 % non-English literature

Stakeholder involvement: Helsinki Commission (HELCOM) involved

BACC Book published in January 2008



Chapter 1Introduction and SummaryLead Authors: Hans von Storch, Anders Omstedt

Chapter 2Past and current climate changeLead Authors: Raino Heino, Heikki Tuomenvirta, Valery Vuglinskiy, Bo Gustafsson

Chapter 3Projections of future anthropogenic climate changeLead Author: L. Phil Graham

Chapter 4Climate-related change in terrestrial and freshwater ecosystemsLead Author: Benjamin Smith

Chapter 5Climate-related marine ecosystem changeLead Authors: Joachim W. Dippner, Ilppo Vuorinen

AnnexesVarious authors provide up-to-date background “textbook” knowledge on all aspects of BACC

BACC



BACC

Changes in Baltic Sea basin near-surface air temperature for the period 1871-2004 relative to 1961-1990

• Significant positive trend with regional and seasonal variations

• Warming trend in the north: + 1 ºC; in the south: + 0.7 ºC per 100 yrs (basin: + 0.85 ºC)

• Warming trend is largest in spring

• Regional change is slightly larger than on the global scale (IPCC-AR4: + 0.74 ºC per 100 yrs)

Air TemperaturePast and current climate change



BACC

Changes of precipitation over the Baltic Sea basin as ratios of the period 1976-2000 relative to 1951-1975

Light green = Precipitation decreaseDark green = Precipitation increase

PrecipitationPast and current climate change

Large spatial and seasonal variations of precipitation, but trends towards…

More rain in winter (especially in the south)

More rain in spring (especially in the north)

Less rain in summer (especially in the south)

Overall slight increase



BACC

Tornionjoki

20.4.

30.4.

10.5.

20.5.

30.5.

9.6.

19.6.

1693 1743 1793 1843 1893 1943 1993

Year

Bre

ak-u

p (

dat

e)River icePast and current climate change

Earlier ice break up in Tornionjoki river (Finland)



BACC

Wind and StorminessPast and current climate change

Number of low pressure systems (p<980 hPa) in Stockholm and Lund

There is NO trend in windiness or storminess over the Baltic Sea Basin!



BACC

Sea icePast and current climate change

Winter 2007/2008 mildest ever recorded



BACC

Projections of future anthropogenic climate change

RCM projection for 2071-2100 relative to 1961-1990

(A2 scenario)

Air Temperature

Winter

RCM: RCAO

RCM: HIRHAM

GCM: HadAM3H GCM: ECHAM4/OPYC



BACC

Projections of future anthropogenic climate change Air Temperature

Air Temperature Animation


(A2 scenario)



BACC

Projections of future anthropogenic climate change Precipitation

Precipitation Animation


(A2 scenario)



BACC


RCAO projections for 2071-2100 relative to 1961-1990

Discharge peaks come earlier in the year

Overall amounts increased

Lower salinities expected

Total riverine discharge to the Baltic Sea



BACC


Mean number of ice days simulated by RCAO

Present winter For the period 2071-2100 using the B2 emission scenario

For the period 2071-2100 using the A2 emission scenario

Sea ice



The expected future warming is associated to a possibly accelerated continuation of the present trends in

(i) Earlier spring phenological phases,

(ii) Northward species shifts

(iii) Increased growth and vigour of vegetation

Terrestrial ecosystems

Terrestrial ecosystems in the south are projected to be a carbon source by the end of the century

BACC



Impacts on marine ecosystems

… increase of temperature…• Higher metabolic rates

• Impact on acclimation capacity

• Reduce the general fitness

• Reduce enzyme activities

• Shift in species composition (phytoplankton)

• Enhanced cyanobacteria blooms

… reduction in sea ice…• Ringed seal survival

… decrease of salinity…• Osmotic stress

• Shift in species composition (phyto– & zooplankton)

• Egg survival

• Food quality for fish (growth rate)

• Distribution of benthos

• Reduction of fitness

• Invading species

BACC



1st BACC II Lead Author Team Meeting in Gothenburg, Sweden23-24 November 2010

2nd BACC II Lead Author Team Meeting in Hamburg, Germany28-29 March 2011

BACC II: An update to BACC to be published in 2014



BACC II: An update to BACC to be published in 2014

Science Steering Group constituted mostly from BACC I Lead Authors New lead authors and contributing authors (23 to date)

New in BACC II

Past climate variability: Holocene (10.000 yr) and historical time frame (1000 yr) Sea level change Socio-economic impacts: Agriculture and forestry, Urban complexes,

Fisheries and aquaculture Attributing causes of regional climate change:

Global warming, aerosols (natural and pollutants), land cover and resource

management

„Summary brochure for policy makers and the public“



Value for the managing of scientific knowledge

Value for society of BACC-type assessment reports

• Overview over the current conensus (and dissensus) view

over the current state of research for

scientists stakeholders public

Go to our websites

www.baltex-research.eu/BACC2

thebaccblog.blogspot.com



Thank you!

bssc 2011 st. petersburg, 26 august 2011

Documents

eumarcus reckermann

plausibleprinciples

climate changes

bacc author teamwww

summarylead authors

lead authors responsible

scientific communityediting

ipcc process