### Sea-level rise (since the pre-industrial age)

| #### Sea-level rise (since the pre-industrial age)
| unit: cm dimension: contributor

This indicator presents the sea level rise since the pre-industrial age (1765) calculated by the Sea-Level Rise Model (SLRM) caused by the following contributors:

- global-warming induced thermal expansion of oceans
- melting of small glaciers
- melting of the Greenland and Antarctica ice sheets

1. Thermal expansion. Global warming is thought to change sea level mainly through thermal expansion of the oceans. In SLRM, the thermal expansion is a non-linear function of the temperature in each oceanic layer (determined by UDCM).

2. Small glaciers. The influence by small glaciers is determined by the global mean surface temperature change (from UDCM), a minimum temperature at which the glacier would eventually disappear, an initial ice volume, the equilibrium ice volume and the glacier response time. To take regional variations into account, a set of minimum temperatures and response times is applied.

3. Greenland and Antarctica. The influence by the Greenland and Antarctica ice sheets is calculated with two factors: one that represents the gain or loss of ice due to the initial state of the ice sheet (in 1880) plus a factor to describe the influence of temperature change on the ice sheets.
The West Antarctic Ice Sheet (WAIS) contains enough ice to raise the sea level by 6 metres and has attracted special attention because it may result in rapid ice discharge due to weak surrounding ice shelves. However, it was concluded that this was very unlikely to happen in the 21st century.

The uncertainty in these indicators is large: the ranges for the period 1990-2100 are 0.11 to 0.43 m for thermal expansion, 0.04 to 0.17 m for the glacier contribution, -0.01 to 0.07 m for the Greenland ice sheet and –0.12 to –0.02 m for the Antarctica contribution.