Reference:

Phipps, S. J., M. A. King, J. L. Roberts and X. Zhang: The commitment
to global sea level rise over the next 500 years: exploring the threat
of the Antarctic Ice Sheet to coastal infrastructure, Australasian
Coasts and Ports 2019, Hobart, Tasmania, Australia, 10-13 September
2019.


Abstract:

Within Australia alone, more than A$226 billion of coastal
infrastructure is vulnerable to the anticipated rise in sea level by
the end of the century. The IPCC Fifth Assessment Report concludes
that the likely increase in global mean sea level during the 21st
century ranges from 26-55 centimetres (under the low-end RCP2.6
climate scenario) to 45-82 centimetres (under the high-end RCP8.5
climate scenario). However, these projections do not take into account
the potential for collapse of the marine-based sectors of the
Antarctic Ice Sheet.

Recent evidence has indicated that the IPCC projections may be
under-estimates, with sea level increases of up to 2.5 metres possible
by the end of the 21st century. Modelling studies have also
demonstrated the potential for the Antarctic Ice Sheet to undergo
irreversible collapse during the coming centuries, leading to dramatic
increases in global sea level on time scales relevant to critical
coastal infrastructure such as refineries and airports. The most
extreme prediction is that Antarctica could contribute 15.65±2.00
metres to global sea level by the year 2500.

Here, we combine climate modelling and ice sheet modelling to explore
the evolution of the Antarctic Ice Sheet over the next 500 years under
a range of climate scenarios. We run the models many times to take
into account gaps in our understanding of ice sheet dynamics. This
allows us to generate robust projections of the Antarctic contribution
to global sea level from the present to the year 2500, complete with
quantified confidence intervals. We conclude that the sea level
contribution during the 21st century will be modest, consistent with
the IPCC Fifth Assessment Report, but that melting of the Antarctic
Ice Sheet will accelerate thereafter. By the year 2500, we predict
that the Antarctic contribution to global sea level will be at least 5
metres.


Contents:

Output of the Parallel Ice Sheet Model (PISM) version 0.7.3 for the 34
ensemble members presented.

Topography            Bedmap2 (doi:10.5194/tc-7-375-2013)
Heat flow             AN1 (doi:10.1002/2015JB011917)

Reference state       RACMO2.3 (doi:10.3189/2014JoG14J051)
Climate forcing       CSIRO-Mk3L-1-2 (doi:10.1175/JCLI-D-12-00108.1)


Experiments:

historical     Historical (1-2000 CE)
rcp26          RCP2.6 (2001-2500 CE)
rcp45          RCP4.5 (2001-2500 CE)
rcp6           RCP6   (2001-2500 CE)
rcp85          RCP8.5 (2001-2500 CE)


Variables:

iarea     Total ice area (m2)	
ivol      Total ice volume (m3)
slvol     Total sea level relevant ice in sea level equivalent (m)
thk       Land ice thickness (m)
usurf     Ice upper surface elevation (m)


Contact:

Steven Phipps <Steven.Phipps@utas.edu.au>