1. Relationship between global mean sea-level, global mean temperature and heat-flux in a climate simulation of the past millennium Hans von Storch, Eduardo Zorita and F. González-Rouco GKSS Research Centre, Geesthacht, Germany Universidad Complutense Madrid

2. Factors governing 20 th century global annual sea-level rise: Thermal expansion of the ocean Mass balance of land ice Management of natural and artificial aquifers

3. Factors governing 20 th century global annual sea-level rise: Thermal expansion of the ocean Mass balance of land ice Management of natural and artificial aquifers Estimated by climate models, though uncertain (20-60 cm rise for 2100 )‏ Uncertain, not estimated by current global climate models

4. d (sea-level)/dt ~ Temperature sea-level rate temperature Rahmstorf 2007 Semi-empirical methods linking global temperature and sea-level (rate)‏ Rahmsorf, 2007; Grinsted et al, 2009 Idea: -design a statistical model with global temperature as predictor to infer global sea-level (rate) changes: SL (t) = function (global T and some parameters)‏ -Estimate the value of the parameters by fitting F to the observational record -Predict SL(future) from the simulated future global T

5. The risk of correlation analysis with non-stationary series global sea-level rate global mean temperature Rahmstorf 2007

6. The risk of correlation analysis with non-stationary series global sea-level rate global mean temperature

7. The observational record is short and shows a strong trend How to test whether the estimated parameters are correct? Test the whole idea in the virtual reality produced by global coupled atmosphere-ocean model for long periods of time (with temperature ups and downs -> more real degrees of freedom)‏ Advantage: everything is known Disadvantage: land ice melting is poorly represented

8. Global climate simulation of the past millennium Model ECHO-G (but results from HadCM3 simulation will be also shown)‏ ECHO-G Model used in IPCC AR4 Atmospheric model ECHAM4 19 levels, 3.75x3.75 deg res. Ocean model HOPE 20 levels, 2 x2 deg res. Flux correction applied spatial average zero

9. How realistic is the simulation of the thermosteric sea-level variations? Energy-balance-upwellling-diffusion model ECHO-G full-blown IPCC climate model

10. Realistic simulation of recent thermosteric sea-level rise

11. Possible predictors to determine sea-level rise

12. The relationship between global T and global sea-level rate of change dH/dt is not stable through time

13. Unstable relationship between global T and global sea-level rate through time

14. More stable relationship between global T rate and global sea-level rate

15. Conclusions -The relationship between global temperature and thermosteric sea-level can be more complex than a simple linear regression -Heat flux into the ocean seems to be a good predictor for the thermosteric sea-level rise. -To explore the relationship between external climate forcing and sea-level rise