UK Climate Projections 2009 (UKCP09) sea level rise data provides projections of changes in absolute sea level rise in waters surrounding the UK and changes in relative sea level for coastal areas, where the influence of land movements is considered (and data included here) over the period 1999-2099. Data are provided for three emissions scenarios: Low (IPCC SRES: B1), Medium (IPCC SRES: A1B), and High (IPCC SRES: A1FI).

These projections also include a high risk, low probability scenario (known as the H++ scenario). The H++ scenario has been included to reflect the fact that there considerable uncertainties about the upper limit of absolute sea-level rise. This scenario relies, in part, on expert judgement and is designed to encourage users to think about thresholds of existing systems and the limits to adaptation.

Note: Unlike some other components of UKCP09, the sea level projections are not probabilistic. They provide a frequency distribution of projections based on results from eleven models contributed to the IPCC Fourth Assessment Report. The model projections of sea level rise have not been weighted based on comparison with historical sea level observations, and are therefore treated as equally plausible.

More information about the sea level rise methodology (including assumptions and caveats) is given in Chapter 3 of the Marine & coastal projections report.