1. 1 Scientific tools for public-science interaction on regional climate change & policy Hans von Storch Institut für Küstenforschung, GKSS Forschungszentrum Geesthacht clisap-Exzellenzzentrum, Klimacampus, Universität Hamburg

2. 2 Needed: Separation of popular constructions in the media and of scientifically valid assessments. Generally understandable description of recent and ongoing regional climate change based on scientific results Generally understandable description of possible regional climate changes in the future („scenarios“) Analysis and derivation of options, from reduction of emissions, to better adaptation, reduction of vulnerability to local mitigation of climate related change. Assessment of knowledge on regional climate change (e.g., BACC) derived with scientific methods

3. 3 A few facts Climate change is a „constructed“ issue. Except for temperature-related ohenomena, people do hardly experience „climate change“. One construction is scientific, i.e. an „objective“ analysis of observations and interpretation by theories. The other construction is cultural, in particular maintained and transformed by the public media.

4. 4 Lund and Stockholm Two different construction of „climate change“ – scientific and cultural – which is more powerful? Cultural: „Klimakatastrophe“ Scientific: man-made change is real, can be mitigated to some extent but not completely avoided Storms

5. 5 A few facts Climate is changing on time scales of decades and centuries. Presently climate is changing mainly because of elevated concentrations of greenhouse gases in the atmosphere. This change is best detectable in temperature and related quantities, and will become visible during this century also in other variables, in particular related to the water cycle. Climate change has an impact on social life and ecosystem functioning.

6. 6 Possible Reponses to Anthropogenic Climate Change In the interacting environment-and-society system, we have two classes of options for response: trying to avoid man-made changes („mitigation“) – this has different dimensions, namely avoiding elevated levels of GHG concentrations by reduced emissions; by intensified sinks; by geo- engineering the global albedo, or regional and local conditions. adapting to man-made changes („adaptation“) of climate. In principle, limiting the cause of anthropogenic climate change (i.e., reduction of emissions) is preferable over adaptation, but complete mitigation seems impossible so that the best strategy is to mitigate as much as affordable and to minimize negative consequences by adaptation.

7. 7 The science-.policy/public interaction is not an issue of „knowledge speaks to power“. The problem is not that the public is stupid or uneducated. The problem is that the scientific knowledge is confronted on the „explanation marked“ with other forms of knowledge (pre-scientific, outdated; traditional, morphed by different interests). Scientific knowledge does not necessarily “win” this competition. The social process „science“ is influenced by these other knowledge forms. Science can not be objective but should nevertheless strive to be so. Knowledge market

8. 8 Scientific needs Analysis of cultural construct of climate change, including common exaggeration in the media. Determination of response options on the local and regional scale: mainly adaptation but also regional and local mitigation. Two-way interaction of stakeholders and climate knowledge brokers in „Klimabureaus“. Analysis of consensus on relevant issues (climate consensus reports). Description of recent and present changes. Projection of possible future changes, which are dynamically consistent and possible („scenarios“).

9. 9 9 Sturmfluten Stürme/Wind Norddeutschland Norddeutsches Klimabüro http://www.norddeutsches-klimabuero.de email: info@norddeutsches-klimabuero.deSeegang

10. 10 What do we offer? Communication of regional climate change information. Support for correct use and interpretation of regional climate changes scenarios. Determination of informational and interpretative needs among regional stakeholders

11. 11 Gill et al.,2007 A mitigation option: reversing (part of) the urban warming by „regional geo-engineering“

12. 12 Constraining the impact of storm surges (and at the same time, sediment flux) in the river Elbe and in Hamburg Flooding Areas in the upper Estuary Sediment Management considering the whole System Dissipation of incoming tidal energy by hydraulic engineering especially in the mouth of the estuary 2030 2085

13. 13 New planning in Schleswig Holstein for improving dikes, with an option for further enhancement

14. 14 Assessing scientifically legitimate knwoledge claims about regional climate change

15. 15 The Climate Change Assessment: Report for the Baltic Sea catchment - BACC An effort to establish which scientifically legitimized knowledge about anthropogenic climate change is available for the Baltic Sea catchment. Approximately 80 scientist from 10 countries have documented and assessed the published knowledge. The assessment has been accepted by the inter- governmental HELCOM commission as a basis for its future deliberations. In 2012 a second assessment report (BACC II) will be published.

16. 16 Working group BACC of GEWEX program BALTEX. The BACC Project integrates available knowledge of historical, current and expected future climate change. The unique feature of BACC is the combination of evidence on climate change and related impacts on marine, freshwater and terrestrial ecosystems in the Baltic Sea basin (catchment and water body). It is the first systematic scientific effort for assessing climate change in the Baltic Sea region. The results have not been influenced by either political or special interests.

17. 17  Presently a warming is going on in the Baltic Sea region, and will continue throughout the 21st century.  BACC considers it plausible that this warming is at least partly related to anthropogenic factors.  So far, and in the next few decades, the signal is limited to temperature and directly related variables, such as ice conditions.  Later, changes in the water cycle are expected to become obvious.  This regional warming will have a variety of effects on terrestrial and marine ecosystems – some predictable such as the changes in the phenology others so far hardly predictable. BACC, in short …

18. 18 Note – time series has been „cleaned“; instrumental inhomogeneities and local effects (such as growing cities) have been taken out. Air-temperature

19. 19 Mean rate of change (days/year) of date of leaf unfolding in birch, 1958-2000 Terrestrial ecosystems

20. 20 Mean number of ice days in a present day simulation (top) and two scenarios of 2070- 2100 (bottom)

21. 21 Climate assessment for the metropolitan region of Hamburg Presently, a climate assessment report about the scientifically documented knowledge of climate change in the region of Hamburg is prepared. This is an activity of the Climate Center of Excellence CLISAP at the University of Hamburg, jointly operated with GKSS and MPI. The effort is supported by the Senate of Hamburg and by the Environmental Ministry of Schleswig Holstein. Publication of results on 25 November 2009.

22. 22 Suitable data sets describing recent, ongoing and possible future regional climate change

23. 23 GKSS in Geesthacht The CoastDat data set: Long (50 years) and high-resolution reconstructions of recent offshore and coastal conditions mainly in terms of wind, storms, waves, surges and currents and other variables in N Europe Scenarios (100 years) of possible consistent futures of coastal and offshore conditions extension – ecological variables, Baltic Sea, E Asia, Laptev Sea Clients: Governmental: various coastal agencies dealing with coastal defense and coastal traffic Companies: assessments of risks (ship and offshore building and operations) and opportunities (wind energy) General public / media: explanations of causes of change; perspectives and options of change www.coastdat.de

24. 24 RCAO A2 - CTL: changes in 99 %iles of wind speed ; 6 hourly, DJF; west wind sector selected Scenarios for 2085 Woth, personal communication HIRHAM

25. 25 Final comment: science, policy and responsibility (Geophysical, ecological) Science should not formulate policy, but prepare the factual basis for decision makers, who consider apart of geophysical and ecological facts also other, in particular normative arguments. Climate change is real and mostly caused by human emissions. Society wants to avoid such a change; thus, reductions of emissions are needed („mitigation“). Any conceivable mitigation policy will not lead to an ending or even reversal of global warming; thus the need for adaptation emerges. Mitigation should be the main issue for policy at national and European level; adaptation should be chiefly considered on the regional and local level.

26. 26 Workshop 2: Regional Policy in view of Climate Change Workshop coordinator: Jan Thiele BSSSC Secretariat, Hamburg, Germany Chair: Hans-Jörg Isemer International BALTEX Secretariat, GKSS Research Centre, Geesthacht, Germany

27. 27 Workshop 2: Regional Policy in view of Climate Change 1. Sonja Deppisch: Examples of research-practice projects on climate change adaptation in the Baltic Sea Region 2. Heikki Tuomenvirta: Climate change information flow from research to policy and decision making in Norway, Sweden and Finland 3. Elysabeth Frydenlund: An energy perspective on regional policy in view of climate change – Inland Norway 4. Holger Lange: Hamburg climate policy: Mitigation and adaptation Workshop contributions