Antarctic glaciers are experiencing rapid changes due to climate change. Satellite observations show glaciers in the Amundsen Sea sector of West Antarctica retreating rapidly, with Pine Island Glacier retreating 31 km and Thwaites Glacier retreating 14 km between 1992 and 2011. This sector contributes significantly to sea level rise and contains enough ice to raise sea levels by 1.2 meters. Reconstructing ice sheet changes during the Last Glacial Termination has shown that Antarctic ice sheet mass loss was sustained by feedbacks from warm Circumpolar Deep Water, and similar feedbacks today could accelerate sea level rise. If emissions continue unabated, Antarctica has the potential to contribute over 1 meter of sea level rise by 2100 and

1. Antarctic glaciers are exquisite and awe-inspiring. Its beauty is said to be haunting, the
still waters which are remarkably calmoffered mirror-like reflections of the brilliant blue sky
above and glaciers are much like carved into gothic designs—seeing in the shapes of the ice
the ruins of civilization, collapsed buildings, cathedrals and minarets. Beauty on hand, it also
holds great superlatives: it is the driest continent, the remotest, the coldest, the windiest
and the highest on average.
Together with these greatness, its continuous battle against climate change
intensifies— changes in atmospheric and ocean temperatures has gradually led to increasing
ice shelf collapse and rapid glacier recession, posing great threat not only to its remarkable
features but also to the survival rate of humankind.
1For more than two weeks in January 2016, a passive
microwave satellite observed surface ice melt two
times the size of California.
The critical boundary between the ocean and grounded ice which delineates where ice
dismounts from the bed and becomes afloat and frictionless at its base is called the

2. grounding line. Its location is important
because mass loss of the continent is
strongly dependent to changes in the
ice shelves and their grounding lines.
Using the Earth Remote Sensing
(ERS-1/2) satellite radar interferometry
from 1992 to 2011, its position is
mapped accurately at a high spatial
resolution, simultaneously and uniquely
over large areas.
In the Amundsen Sea (AS) sector
of West Antarctica, grounding line
mapping has revealed major glacier
changes in the 1990s.
 Pine Island Glacier retreated 31
km at its center, with most retreat
in 2005-2009 when the glacier
undergrounded from its ice plain.
 Thwaites Glacier retreated 14 km
along its fast flow core and 1 to 9
km along the sides.
 Haynes Glacier retreated 10 km
along its flanks.
 Smith/ Kohler glaciers retreated the most, 35 km along its ice plain, and its ice shelf
pinning points are vanishing
The AS is a dominant contributor to the mass loss from the Antarctic ice sheet at present, with
losses driven almost entirely by increases in flow speed. This sector is a global significance since
it contains enough ice to raise global sea level by 1.2 m.
Disentangling ice-climate feedbacks that are key to future projections can be made
through reconstructing the dynamic response of the Antarctic ice sheets to warming during the
Last Glacial Termination (LGT; 18,000-11,650 yrs. ago). Even though the sequence of events on
this time is reasonably well-known, relatively poor chronological control has precluded precise
alignment of ice, marine and atmospheric records, making it hard to compare relationships

3. between Antarctic ice-sheet
(AIS) dynamics, sea level and
climate change. Presenting
results from a highly-resolved
‘horizontal ice core’ from the
Weddell Sea Embayment have
shown AIS mass-loss across the
full duration of the Antarctic
Cold Reversal (ACR; 14,600-
12,700 yrs ago), with
stabilization during the
subsequent millennia of
atmospheric. Ice-sheet
modelling and Earth-system suggests these contrasting trends were likely Antarctic-wide,
sustained by feedbacks amplified by the delivery of Circumpolar Deep Water onto the
continental shelf.
Given the anti-phase relationship between inter-hemispheric climate trends across the
LGT, findings displayed that Southern Ocean-AIS feedbacks were controlled by global
atmospheric teleconnections. Increasing stratification of the Southern Ocean and
intensification of mid-latitude westerly winds today, such teleconnections could amplify AIS
mass loss and accelerate global sea-level rise.
Future sealevel change hasa strongimpact onthe livelihoodof alarge share of the world’s
population.Sea-level projectionsare thusof great importance withrespecttoanassessmentof
necessarymitigation andadaptationmeasures.The majoruncertaintyinstate-of-the-artprojectionslies
withinthe evolutionof the solidice discharge fromAntarctica,the largestice massonEarth.
The ocean,the ice and the atmosphere are all intrinsicallylinked,andinAntarctica
we nowsee howcomplex changesinatmosphericcirculation,drivenbythe ozone hole
and climate change,are changingoceancirculation.Increasedupwellingof salty,warm
CircumpolarDeepWaterismeltingawaythe base of the ice shelvesandthe grounding
linesof some of the largest,mostvulnerableglaciersandice streamsinAntarctica,
resultingin rapid,far-reachingandirreversible changes.

4. Polartemperaturesoverthe last
several millionyearshave,attimes,been
slightlywarmerthantoday,yet global
mean sea level hasbeen6-9 metershigher
as recentlyasthe Last Interglacial and
possiblyhigherduringthe Pliocene epoch.
In bothcasesthe Antarcticice sheethas
beenimplicatedasthe prime contributor,
hintingatits future vulnerability.
Usinga model couplingice sheet
and eliminateddynamics—including
previouslyunderappreciatedprocesses
linkingatmosphericwarmingwith
hydrofracturing of buttressingice shelves
and structural collapse of marine-terminatingice cliffs—thatiscalibratedagainstPlioceneandlast
Interglacial sea-level estimatesandappliedtofuture greenhousegasemissionscenarios.Antaricahas
the potential tocontribute more thana meterof sea-level rise by2010 and more than 15 metersby
2500, if emissionscontinue unabated.Inthiscase atmosphericwarmingwill soonbecome the dominant
driverof ice loss,butprolongedoceanwarmingwill delayitsrecoveryforthousandsof years.