This is part of the labels / documentation for <a href='http://jcm.chooseclimate.org'>Java Climate Model</a><hr/>

#sealevel		¨oldJCM4 addJCM5		§This module calculates sea-level rise considering thermal expansion of seawater (see @udebclimod,  @oceantempcurves), ice melt from  Greenland and Antarctica. from mountain glaciers, and some other minor sources.

More information about each contributing factor  is given for each curve in  @sealevelrise .
 
Regarding the thermal expansion component, see also @oceantempcurves

Note that sea-level continues to rise long after surface temperature stabilises, due to slow heat uptake into the deep ocean, and slow response of the ice-caps. 
For this reason, it may be useful to extend the  @model_end_year (even up to 3000) when studying sea-level projections.
See also the cross-cutting theme @inertia

££sealevelicemelt 
££sealevelother
££sealevelfuture

You can check JCM predictions with the data from IPCC: see @compareipcc

#sealevelplot		¨oldJCM4		§£>@sealevelrise

#thermexp		¨oldJCM4		§Thermal expansion is calculated by the @udebclimod  with a different expansion coefficient applied to the warming from each ocean layer. The physics of this expansion is relatively well understood. However it depends on the transfer of heat to the deep ocean, which varies in different ocean models.

€€adju You can see this by changing the model in the "GCM-fit" menu (@climodmenu). For example, the fit to  ECHAM4 predicts a much higher sea-level rise than the others, due to its high vertical mixing rate (paradoxically, this also lowers the surface temperature). 
%%(Note that this issue was specific to the UDBB model calibration in IPCC-TAR, rather than intrinsic to the ECHAM model, it does not reappear in AR4).%%

See also @oceantempcurves

#glaciers		¨oldJCM4		§Glaciers outside polar regions. These are already receding fast in many regions and are a clear indicator of warming, they are also important to control water supply to major rivers.

#greenland		¨oldJCM4 addJCM5		§Projections of polar ice melting are very uncertain! 
In Greenland it is anticipated that increased runoff and calving ice-melting will exceed the increase in snowfall, although not in all regions. 
In the longer term, IPCC-TAR predicts that the entire Greenland ice sheet may melt if there is a prolonged regional temperature rise of only 3C. This would lead to a sea-level rise of 5-6m.

£§icemeltupdate

#antarctica		¨oldJCM4 addJCM5		§Projections of polar ice-melting are very uncertain! In Antarctica, for moderate warming it is predicted that ice-melt at the periphery will be more than offset by increased snowfall in the centre of the continent, due to increased evaporation from the ocean, thus reducing sealevel slightly. However the stability of the West Antarctic ice sheet (with similar volume to Greenland) is subject to much debate.

£§icemeltupdate

#rfia		¨oldJCM4		§Constant background change, due to the slow rebound of rocks previously weighed down by former ice sheets.

#freshwater		¨oldJCM4		§Includes increase of water storage in dammed reservoirs, and decrease due to pumping from groundwater aquifers. Potentially a large contribution (see IPCCTARWG1ch11), however even the sign is uncertain, so it cannot be included yet.

#sealevelicemelt		¨oldJCM4 addJCM5		§The ice-melt components are very uncertain. The net effect of Antarctica and Greenland ice sheets depends on a balance between increasing snowfall due to increasing evaporation from a warmer ocean, and increasing melting of ice at the margins. The calculations in JCM are based on simple formulae fitted to data given in IPCC-TAR WG1 chapter 11. The  slow recovery from last ice age is a constant factor, consistent with observations. The moutain glaciers are divided into ten groups using method as for IPCC-SAR , but with parameters updated as for TAR.

£§icemeltupdate

#sealevelother		¨oldJCM4		§Note that local sea-level rise may be different from these global average values due to slow tectonic changes, and changes in atmospheric pressure and wind direction, especially in estuaries. Moreover, melting Antarctic ice raises sealevel more in the northern hemisphere, and vice versa for Greenland, as we shift the earth's centre of gravity.

There may also be a significant effect of changing terrestrial freshwater storage (lakes, dams, groundwater) partly due to anthropogenic activity. However, the uncertainty of this is so great (even regarding the sign), it is not yet included here.
See IPCCTAR WG1 Chapter 11 for more details.

#sealevelfuture		¨fut		§The sea-level module will soon be updated to be consistent with IPCC-AR4.
It is likely that this will substantially increase the projections from ice melting. 

More adjustable parameters should also be added to the ice-melt calcualtion, to illustrate the uncertainty range. 

The vulnerability to sea-level rise is very different for different regions. The new @impacts module should illustrate this, and eventually calculate some impact costs.