Atmosphere Ocean Science Colloquium

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Asymmetry in Regional Sea Level Projections

Speaker: Roderik Van De Wal, Utrecht University

Location: Warren Weaver Hall 1302

Date: Wednesday, September 2, 2015, 3:30 p.m.

Synopsis:

In this presentation I will discuss reasons for variations in projections of regional sea level rise and the uncertainties in these projections. Recent assessments indicate that the probability distribution of the contribution of ice sheet mass loss may well be distributed asymmetrically towards higher projections. In this study we present the consequence of this asymmetry for high-end regional sea level projections. These estimates include gravitational and rotational effects as well as variability caused directly by climate change. The global average 95% percentile for sea level shifts to 26 cm higher values, compared to symmetrical distribution based on the IPCC AR5 report. Regionally both lower (near ice sheets) and higher values (east coast US) are possible depending on the location with respect to ice loading changes. Results diverge even for higher confidence levels and hence this effect is of large importance for coastal defenses as flood risks may increase considerably.