1. 四海 and the challenge of synthesis of knowledge
Hans von Storch and Marcus Reckermann
Helmholtz-Zentrum Geesthacht, Germany
30 mins incl. dicussion
16-17 October Workshop on "Regional Sea Level and Climate Change", 天津 (Tianjin) 

2. Overview The concept and MoU of 四海
Sometimes, scientists from different countries and different disciplines engage in understanding of the dynamics, the state, the links and sensitivities to external forcing, and the perspectives of a certain region – examples are in Northern Europe the Baltic and the North Sea, and in West-Asia the Bo Hai and the Huang Hai. These seas, and their coastal lands are under human pressure, with various conflicts about how to use the marine an coastal resources.
This is the content of the 四海-memorandum.
The need of knowledge consolidation.
For economic and political decision processes knowledge about the system is needed, which is in the scientific community widely accepted, and which includes knowledge about lacks and gaps of knowledge
A example of a successful implementation of such an approach.
Such an international and interdisciplinary approach has been developed for the Baltic Sea region: the research programs BALTEX, and Baltic Earth dealing with great challenges, and the knowledge assessment reports BACC I and II.
A knowledge assessment report was also assembled for the North Sea (NOSCCA)

3. MoU of 四海, signed in Shandong and Germany, in 2015
Coastal Science as own research field
Coasts are those parts of the ocean which are significantly influenced by the neighboring land, be it in terms of currents, winds, temperatures, sea ice, salinity, suspended matter, specific species, and anthropogenic substances; but coasts are also that part of the land which is significantly influenced by the neighboring sea, be it opportunities for transport, risks related to flooding, tsunamis, storm surges, and where the points of departure such as shipping, tourism, and oil and gas extraction are found. Not surprisingly therefore, the science in coastal dynamics and management extends far beyond oceanography.
Certainly oceanography is an important component of the interdisciplinary mix of scientific efforts dealing with coasts, but other fields such as meteorology, coastal engineering, land use planning and management, freshwater hydrology and ecology, climate, sociology and cultural science are also needed for constructing holistic views of the subject of coasts.

4. What makes the issue of coasts special is not only the presence of the “other” counterpart, i.e., the sea versus land and land versus sea, but also the presence of an often dominant factor modifying or even constructing the coast - humans who use the coasts in various ways, conditional upon temporally and culturally varying preferences, who make use of opportunities and try to deal with often great dangers. The German coasts, there is a saying according to which “God created the ocean, but the Frisians created the coast” (the Frisians are people living at the Dutch and German North Sea coast). Because of both, the culturally conditioned values and preferences, and the different geophysical, morphological and ecological set up, the various coasts of this world are very different, and face very different challenges, risks and opportunities. As a consequence coastal science is fragmented into regional research communities; in some quarters coastal sciences is considered as a mere variant of oceanography, and in others it is essentially coastal engineering, and in still others human geography.
The challenge is to bring together these different communities, disciplines, challenges and concepts together, not only within the scientific community but also in a trans-disciplinary effort by combining the real world, in which the coast is subject to competing practices and decisions, with the body of scientific knowledge.
We are convinced that a deepening and a sustainable cooperation between German and Chinese coastal scientists will hold the potential for significant progress in coastal sciences, not only in the two countries but also beyond. We expect synergistic progress, in terms of better understanding of processes, subsystems, the holistically framed system comprising natural dynamics and human interference, and perspectives conditioned by different societal values and preferences, when we consider in parallel, in particular in a comparative mode, the two North German marginal seas of the North Sea and the Baltic Sea, as well as the two Chinese marginal seas Bo Hai and Huang Hai.
This progress will also have a management dimension, an instrumental (monitoring) dimension as well as issues of the built environment (coastal defense, ports, shipping lanes, offshore activity)
What makes the issue of coasts special is not only the presence of the “other” counterpart, i.e., the sea versus land and land versus sea, but also the presence of an often dominant factor modifying or even constructing the coast - humans who use the coasts in various ways, conditional upon temporally and culturally varying preferences, who make use of opportunities and try to deal with often great dangers. Because of both, the culturally conditioned values and preferences, and the different geophysical, morphological and ecological set up, the various coasts of this world are very different, and face very different challenges, risks and opportunities. As a consequence coastal science is fragmented into regional research communities; in some quarters coastal sciences is considered as a mere variant of oceanography, and in others it is essentially coastal engineering, and in still others human geography.
The challenge is to bring together these different communities, disciplines, challenges and concepts together, not only within the scientific community but also in a trans-disciplinary effort by combining the real world, in which the coast is subject to competing practices and decisions, with the body of scientific knowledge.
We are convinced that a deepening and a sustainable cooperation between German and Chinese coastal scientists will hold the potential for significant progress in coastal sciences, not only in the two countries but also beyond. We expect synergistic progress, in terms of better understanding of processes, subsystems, the holistically framed system comprising natural dynamics and human interference, and perspectives conditioned by different societal values and preferences, when we consider in parallel, in particular in a comparative mode, the two North German marginal seas of the North Sea and the Baltic Sea, as well as the two Chinese marginal seas Bo Hai and Huang Hai.
This progress will also have a management dimension, an instrumental (monitoring) dimension as well as issues of the built environment (coastal defense, ports, shipping lanes, offshore activity)

5. Test case: 四海
We focus on the “Four Seas” (四海) not only because many of us are familiar with these seas after many years of scientific analyses, but also because of their societal significance with a broad range of important modes of uses, from oil and gas, nearshore aquaculture, offshore fishery, wind energy, shipping and other industrial activities to tourism and natural preservation. Both systems are made up of one sea which is more enclosed, and another one which is half open to the world ocean. In both systems major ecosystems have their home, but they also serve, or served, as dumping sites for onshore activities. A difference is the fact that the North European seas have many different national coasts while in case of the Chinese seas only a limited number of international partners share responsibility for the marginal seas.
We should also mention the emotional value of the Four Seas for the people living at their coasts – which certainly has an influence on the culture of the regions.
Within the “four seas” concept, we cover issues of hydrodynamics and ecology, of coastal climate of observational projects, the construction of monitoring systems, and the various dimensions of human usages (fisheries, oil and gas, natural reserves...). Other issues, which deserve attention deal with past changes, possible future drivers in changes, the construction of scenarios, the challenge of detecting (changes beyond natural variations) and the attribution (of plausible mechanisms). A particular challenge will be to map similarities and differences of regional societal values, decision procedures and stakeholder networks. Finally, we welcome systematic efforts for assessing the body of scientifically legitimate knowledge and for describing to what extent this knowledge is based on agreement or is contested.

6. Drainage Basin: 2.13 Mill. km2 (20% of the European continent)
The Baltic Sea region
Drainage Basin: Mill. km2 (20% of the European continent)
85 million people in 14 countries
Baltic Sea: km2
St. Petersburg: Northernmost city with > 1 million

7. The Baltic Sea region The North … extensive forests, mostly coniferous
sparsely populated
mostly rocky coasts
subarctic climate in winter
The South…
intense agriculture
densely populated
mostly sandy coasts
moderate climate in winter

8. BALTEX was founded in 1992 as part of the GEWEX programme of WCRP
Marcus Reckermann, International BALTEX Secretariat GEWEX/GHP Meeting, Boulder, 19 October 2011

9. BALTEX Phase I: 1992 – 2003: First 10 year Phase
BALTEX was founded in 1992 as part of the GEWEX programme of WCRP
The hydrological cycle and the exchange of energy between the atmosphere
and the surface of the Earth (pysical part of the climate system)
Major disciplines: Meteorology, Oceanography, Hydrology
Major outcomes of BALTEX Phase I ( :
Building of research and observation network; data exchange and availability, development of coupled regional atmosphere-land-ocean models

10. BALTEX Phase II: 2003 - 2012: Second 10 year Phase
BALTEX Phase II has evolved into an environmental research network dealing with the Earth system of the entire Baltic Sea catchment including terrestrial and marine biogeochemical cycles
Scientific disciplines (in Phase II): Meteorology
Hydrology Climatology Oceanography Biogeochemistry
Important elements are
Climate variability and change
and related impacts on the environment and the human sphere
BALTEX Assessment of Climate Change for the Baltic Sea basin (BACC)

11. Baltic Earth – Earth System Science for the Baltic Sea region
Vision of the new programme
To achieve an improved Earth System understanding of the Baltic Sea region
Interdisciplinary and international collaboration (conferences, workshops, etc.)
Holistic view on the Earth system of the Baltic Sea region, encompassing processes in the atmosphere, on land and in the sea and also in the anthroposphere
“Service to society” in the respect that thematic assessments provide an overview over knowledge gaps which need to be filled (e.g. by funded projects)
Education (summer schools)
Inherits the BALTEX network of scientists and infrastructure

12. Baltic Earth – Science Plan and Grand Challenges
Current Grand Challenges
GC1: Salinity dynamics in the Baltic Sea
GC2: Land-Sea biogeochemical feedbacks in the Baltic Sea region
GC3: Natural hazards and extreme events in the Baltic Sea region
GC4: Understanding sea level dynamics in the Baltic Sea
GC5: Understanding regional variability of water and energy exchanges
GC 6: Multiple drivers of Earth system changes in the Baltic Sea region
The human impact will be assessed at all levels, wherever possible and meaningful
Website:
Baltic Earth Science Plan and Grand Challenges
Flexible science plan with a continuously on-going definition of core research questions which are identified to be key scientific issues, so-called “Grand Challenges” (GCs)
New Grand Challenges will be identified at conferences and by using assessments of existing research by dedicated working groups. Grand Challenges are envisaged to be research foci for periods of about 3-4 years (then terminated or updated)
The new programme will communicate with stakeholders and research funding agencies to promote funding relevant for the Grand Challenges
International embedment (GEWEX, Future Earth)

13. Knowledge consolidation
Sceince generates knowldge about dynamics, links, sensitivites, perspectives of phenomena and developments. Sciene does not provide solutions of problems, but insight into conditions of solutions.
The IPCC presents and assesses the knowledge about climate change and climate impact on the global and all large regions (such as Europe).
BACC (and NOSCCA) is a little cousin of IPCC doing something similar but only for the Baltic Sea region.
The two concepts are broadly similar, but deviate in some significant ways, in particular the non-involvement of governments by BACC.

14. BACC as „regional IPCC“
BALTEX Assessment of Climate Change for the Baltic Sea basin - BACC
An effort to establish which scientifically legitimized knowledge about climate change and its impacts is available for the Baltic Sea catchment.
Approximately 80 scientists from 12 countries have documented and assessed the published knowledge in 2008 in BACC 1; In May 2015, BACC-2 came out, with 141 contributing authors.
The assessment has been accepted by the intergovern- mental HELCOM commission as a basis for its judgment and recommendations.
45 min‘s

15. Principles
The assessment is a synthesis of material drawn comprehensively from the available scientifically legitimate literature (e.g. peer reviewed literature, conference proceedings, reports of scientific institutes).
Influence or funding from groups with a political, economical or ideological agenda is not allowed; however, questions from such groups are welcome.
If a consensus view cannot be found in the above defined literature, this is clearly stated and the differing views are documented. The assessment thus encompasses the knowledge about what scientists agree on but also identify cases of disagreement or knowledge gaps.
The assessment is evaluated by independent scientific reviewers.

16. BACC–1 (2008) results – in short
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.

17. Summary of BACC-2 (2015) New assessment finds results of BACC I valid
Significant detail and additional material has been found and assessed. Some contested issues have been reconciled (e.g. sea surface temperature trends)
Ability to run multi-model ensembles seems a major addition; first signs of detection studies, but attribution still weak
Regional climate models still suffer from partly severe biases; the effect of certain drivers (aerosols, land use change) on regional climate statistics cannot be described by these models.
Data homogeneity is still a problem and sometimes not taken seriously enough
The issue of multiple drivers on ecosystems and socio-economy is recognized, but more efforts to deal with are needed
In many cases, the relative importance of different drivers, not only climate change, needs to be evaluated.

18. Overall Summary of BACC-2 (2015)
Estimates of future deposition and fluxes of substances like sulphur , nitrogen oxides, and carbondioxide depend on future emissions. Atmospheric factors are less important than emission changes.
In the narrow coastal zone plant and animal communities have to adapt to changing climate and to land uplift.
Climate change is a compounding factor for freshwater biogeochemistry. The effect of climate change cannot be quantified yet on a Baltic Basin wide-scale.
Scenario simulations suggest that most probably the Baltic Sea will become more acid in the future.
Increased oxygen deficiency, increased temperature, changed salinity and increased acidification will impact the marine ecosystem in several ways and may erode the resilience of the ecosystem.
Increasing need for adaptive management strategies (forestry, agriculture, urban complexes) in the Baltic Sea Basin that deal with both climate change but also emissions of nutrients, aerosols, carbondioxide and other substances.

19. Climate science has provided sufficient knowledge for societies to decide about limiting climate change
Yes,
- Climate is changing,
- We can not explain this change in terms of temperature without referring to elevated greenhouse gases
When looking at change in general, global climate change is one factor; others may be at work as well, sometimes dominantly so.
Climate change represents a challenge for human societies and ecosystems
Climate change can be limited by limiting the accumulation of greenhouse gases in the atmosphere.
Whether societies agree on joining to actually limit climate change is legitimately a matter of policymaking, of values, of societal choices.

20. Independently of mitigation, a need for adaptation remains – this is a regional and local issue
We have not done our homework
studying jointly ongoing and possible future change.
separating the different causes for observed change.
Climate science needs to deal more with options of adaptation for preparing for societal decisions.
The more successful the climate change limitation policy is, the less adaptation is needed – but adaptation is needed, and is useful in any case, because of reduced vulnerability.
The regional scientific community is asked to generate the needed knowledge. Again, the eventual decisions are a matter of policymaking, of values, of societal choices.

21. Insufficiently explored aspects/knowledge gaps of Baltic Sea climate change
The issue of multiple climate change drivers (aerosols, land-use incl. urbanization)
The issue of multiple pressures on ecosystems and economy (eutrophication and related algae blooms, climate change, pollution, but also shipping and off-shore wind power and other off-shore activities, tourism, natural conservation and agriculture, fisheries and pollution)
Detection of non-natural influence on regional warming. Can be explained only if increased greenhouse gas concentrations contribute. Present trend consistent with model scenarios.
Detection of non-natural component in trends of precipitation amounts; present trends much larger than what is anticipated by models; thus no consistent explanation for the time being.
Lack of studies on detection of changes in other variables (e.g. snow cover, runoff, sea ice)
Lack of studies of the effect of other drivers (reduction of industrial aerosols, land use change)

22. Suggestions Accepting coastal science as a own research field.
Accepting that regional research needs interdisciplinary and international cooperation.
The level of cooperation in China is sometimes too little.
The Baltic Sea, with BALTEX, Baltic Earth and BACC are excellent examples for such a regional, interdisciplinary and international cooperation