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

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August Overview 1.Examples and principles for BACC-type assessments 2.BACC results (published 2008) 3.BACC 2

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

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August BACC-like assessments BACC II ( ) NOSCCA North Sea Region Climate Change Assessment ( ) 2 BACC ( ) Climate Report for the Metropolitan Region of Hamburg ( )

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August BACC Science Steering Committee Contributing authors Management and Coordination ( BALTEX Secretariat ) Expert review 1 st draft Publication selects 2 nd 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

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August 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 - No unpublished results Objectivity: No mixing of personal views, agendas or missions to be mixed up with the scientific status; consensus view to be reached if possible If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

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

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August Chapter 1 Introduction and Summary Lead Authors: Hans von Storch, Anders Omstedt Chapter 2 Past and current climate change Lead Authors: Raino Heino, Heikki Tuomenvirta, Valery Vuglinskiy, Bo Gustafsson Chapter 3 Projections of future anthropogenic climate change Lead Author: L. Phil Graham Chapter 4 Climate-related change in terrestrial and freshwater ecosystems Lead Author: Benjamin Smith Chapter 5 Climate-related marine ecosystem change Lead Authors: Joachim W. Dippner, Ilppo Vuorinen Annexes Various authors provide up-to-date background “textbook” knowledge on all aspects of BACC BACC

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August BACC Changes in Baltic Sea basin near- surface air temperature for the period relative to Significant positive trend with regional and seasonal variations Warming trend in the north: + 1 ºC; in the south: ºC per 100 yrs (basin: ºC) Warming trend is largest in spring Regional change is slightly larger than on the global scale (IPCC-AR4: ºC per 100 yrs) Air Temperature Past and current climate change

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August BACC Changes of precipitation over the Baltic Sea basin as ratios of the period relative to Light green = Precipitation decrease Dark green = Precipitation increase Precipitation Past 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

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August BACC River ice Past and current climate change Earlier ice break up in Tornionjoki river (Finland)

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August BACC Wind and Storminess Past 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!

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August BACC Sea ice Past and current climate change Winter 2007/2008 mildest ever recorded

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August BACC Projections of future anthropogenic climate change RCM projection for relative to (A2 scenario) Air Temperature Winter RCM: RCAO RCM: HIRHAM GCM: HadAM3H GCM: ECHAM4/OPYC

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August BACC Projections of future anthropogenic climate change Air Temperature Air Temperature Animation RCM projection for relative to (A2 scenario)

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August BACC Projections of future anthropogenic climate change RCM projection for relative to (A2 scenario) Air Temperature Winter RCM: RCAO RCM: HIRHAM GCM: HadAM3H GCM: ECHAM4/OPYC Warming in Winter esp. in eastern basin

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August BACC Projections of future anthropogenic climate change RCM: RCAO RCM: HIRHAM GCM: HadAM3H GCM: ECHAM4/OPYC RCM projection for relative to (A2 scenario) Air Temperature Summer Warming in Summer strongest in southern basin

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August BACC Projections of future anthropogenic climate change Precipitation Precipitation Animation RCM projection for relative to (A2 scenario)

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August BACC Projections of future anthropogenic climate change RCM projection for relative to (A2 scenario) Precipitation Winter RCM: RCAO RCM: HIRHAM GCM: HadAM3H GCM: ECHAM4/OPYC Wetter in Winter basinwide

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August BACC Projections of future anthropogenic climate change RCM projection for relative to (A2 scenario) Precipitation Summer RCM: RCAO RCM: HIRHAM GCM: HadAM3H GCM: ECHAM4/OPYC Dryer in Summer in the southern basin

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August BACC Projections of future anthropogenic climate change RCAO projections for relative to Discharge peaks come earlier in the year Overall amounts increased Lower salinities expected Total riverine discharge to the Baltic Sea

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August BACC Projections of future anthropogenic climate change Mean number of ice days simulated by RCAO Present winterFor the period using the B2 emission scenario For the period using the A2 emission scenario Sea ice

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

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

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August st BACC II Lead Author Team Meeting in Gothenburg, Sweden November nd BACC II Lead Author Team Meeting in Hamburg, Germany March 2011 BACC II: An update to BACC to be published in 2014

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

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August 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 thebaccblog.blogspot.com

Marcus Reckermann, International BALTEX Secretariat | BSSC 2011, St. Petersburg, 26 August Thank you!