hans von storch institute of coastal research helmholtz ze ntrum geesthacht und
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Engineering Adaptation Strategies and Infrastructure Design Requirements to Deal with Climate Uncertainty –
Uncertainty, Certainty (and the Case of Coastal Defense)
Hans von StorchInstitute of Coastal Research
Helmholtz Zentrum Geesthachtund
Klimacampus Hamburg
6th International Conference on Water Resources and Environment Research (ICWRER) Koblenz, Germany, June 3–7 2013.
Climate – Knowledge Uncertainty
• Detectability of change• Characteristics of change: intensity, speed,
signal-to-noise ratio (conditional upon time)• Attributability of change (various drivers)• Intensity and effectivity of claimsmaking by
economic stakeholders and green ideology (post-normal science)
• Presence and emergence of other drivers
Certainties• Risks exist and may change, some will.• Climate (statistics of weather) is changing – as well as
associated probabilities of hazardous situations – due to elevated GHG levels.
• A new “stationary” state will hardly be reached; statistics are getting instationary.
• The level of adaptation to change depends on the success of limiting the change (Klimaschutz)
• Scientific skeptic is needed.• Overselling of claims-making is counterproductive on the
long run.
Certainties- the time dimension
• Learning in time – in 10 years we know more than today, in 20 years more than in 10 years.
• Societal values change in time• Technology changes – new, cheaper and more
flexible answers to challenges will be available.• Drivers of change will become more – some
gradually, some abrupt and surprising.• Success of limiting anthropogenic climate change
gradually becomes a “known”
Consequences for today
• Maintenance and regular modernization should consider perspective of future change and flexibility in responding to such change.
• Decision needed as to when new adaptation measures should be implemented.
• Consideration of change of all drivers.• Societal debate needed about options and timing.• Check of societal claims-making reflecting special
interests.
Research Needs
• Development of new or improved technology options for dealing with present and changing risk.
• Monitoring of environmental state, which allows detecting changing risks and attributing to causes.
Coastal Defense: Detection, Attribution
37 year trencs (2 x nodal tide) of regional sea level in the German Bight
black, green: two reconstruction methodsrot – Cuxhaven, Albrecht et al. 2011
Difference of maximum heights in Hamburg and Cuxhaven
Storm surges in Hamburg elevated because of modifying the river Elbe – both coastal defense and shipping channel deepening
Green ideology misleading the public
Claimed flooding associated with a sea level rise of 1 (?) m.
Area protected by contemporary coastal defense against “normal” high tide sea level.
Coastal DefenseAnalysis for Coastal Defense in Schleswig Holstein (Landtag, Kiel), in 2009
Fortification of dikes in Schleswig-Holstein
Significant drivers of changing storm surge heights
Recent changes 1967-2008
Possible changes until 2030
Possible changes until 2100
Global mean sea level rise
ca. 2 dm ca. 1 – 2 dm
ca. 2 – 8 dm
Meteororological short term effects (storms)
none ca. 0 – 1 dm
ca. 1 – 3 dm
Regional and local sea level change
ca. 2 dm So far unknown
So far unknown
waves none So far unknown
So far unknown
tides Regionally very
different
So far unknown
So far unknown
bathymetry Regionally very
different
So far unknown
So far unknown
Niemeyer & Kaiser 2008, NLWKN
Currently overtopping tolerances: 3% of all – Lower Saxony 2 l/(m∙s) – Masterplan
Schleswig-Holstein 0,1-1,0 l/(m∙s) – The Netherlands
Results of overtopping test in Delfzijl/NL No damage up to 50 l / (m s)∙ No severe damage at 50 l (m ∙ s) after artificial damage still functioning
Technology: Dyke overtopping tolerance
Overall conclusion: Time!When adapting to and talking about climate change three major, often overseen issues are
- The issue is not new risk, but changing risk- Time is a key dimension – change occurs in time;
development is instationary.- Knowledge, drivers and options for adaptation
change in time.
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