3.5 Relative sea level rise

In this section we combine absolute sea level changes and vertical land movements into estimates of relative sea level rise. This uses the absolute sea level rise estimates for the UK from Table 3.3 and the land movement estimates from Bradley et al. (2008) (Figure 3.5).

Assuming that the vertical land movement rates shown in Figure 3.5 will remain relatively constant over the 21st century, a yearly time series of the influence of vertical land movement on relative sea level was calculated for four sample locations (London, Cardiff, Edinburgh and Belfast). Subtracting these vertical land movement time series from the absolute sea level rise (averaged around the UK, as was done for Figure 3.4) gives time series of relative sea level rise for the low, medium and high emissions scenarios. These projections are given in Table 3.4 (for the central estimate) and shown in Figure 3.6 along with the 5th to 95th percentile range. This range does not include any land movement uncertainty, although Section 3.4 and the Annex suggests this is likely to be small compared to that in the absolute sea level rise estimates. In the User Interface of UKCP09 the user can select projected relative sea level changes for a range of coastal locations. An example map of relative sea level change (using the medium emissions central sea level rise estimate) is shown in Figure 3.7.