Earth's ice imbalance

Abstract. We combine satellite observations and numerical models to show that Earth lost 28 trillion tonnes of ice between 1994 and 2017. Arctic sea ice (7.6 trillion tonnes), Antarctic ice shelves (6.5 trillion tonnes), mountain glaciers (6.1 trillion tonnes), the Greenland ice sheet (3.8 trillion tonnes), the Antarctic ice sheet (2.5 trillion tonnes), and Southern Ocean sea ice (0.9 trillion tonnes) have all decreased in mass. Just over half (58 %) of the ice loss was from the Northern Hemisphere, and the remainder (42 %) was from the Southern Hemisphere. The rate of ice loss has risen by 57 % since the 1990s – from 0.8 to 1.2 trillion tonnes per year – owing to increased losses from mountain glaciers, Antarctica, Greenland and from Antarctic ice shelves. During the same period, the loss of grounded ice from the Antarctic and Greenland ice sheets and mountain glaciers raised the global sea level by 34.6 ± 3.1 mm. The majority of all ice losses were driven by atmospheric melting (68 % from Arctic sea ice, mountain glaciers ice shelf calving and ice sheet surface mass balance), with the remaining losses (32 % from ice sheet discharge and ice shelf thinning) being driven by oceanic melting. Altogether, these elements of the cryosphere have taken up 3.2 % of the global energy imbalance.

[1]  Review of "Review Article: Earth's ice imbalance" , 2020 .

[2]  R. Mottram,et al.  Ice-sheet losses track high-end sea-level rise projections , 2020, Nature Climate Change.

[3]  H. Fricker,et al.  Interannual variations in meltwater input to the Southern Ocean from Antarctic ice shelves , 2020, Nature Geoscience.

[4]  S. Plummer,et al.  Ice loss in High Mountain Asia and the Gulf of Alaska observed by CryoSat-2 swath altimetry between 2010 and 2019 , 2020 .

[5]  C. Bitz,et al.  Antarctic Sea Ice Area in CMIP6 , 2020, Geophysical Research Letters.

[6]  C. Derksen,et al.  Patterns and trends of Northern Hemisphere snow mass from 1980 to 2018 , 2020, Nature.

[7]  F. Landerer,et al.  Continuity of Ice Sheet Mass Loss in Greenland and Antarctica From the GRACE and GRACE Follow‐On Missions , 2020, Geophysical Research Letters.

[8]  S. Seneviratne,et al.  Heat stored in the Earth system: where does the energy go? , 2020, Earth System Science Data.

[9]  R. Kwok,et al.  Enhanced eddy activity in the Beaufort Gyre in response to sea ice loss , 2020, Nature Communications.

[10]  B. Osmanoglu,et al.  A Systematic, Regional Assessment of High Mountain Asia Glacier Mass Balance , 2020, Frontiers in Earth Science.

[11]  Eric Rignot,et al.  Mass balance of the Greenland Ice Sheet from 1992 to 2018 , 2019, Nature.

[12]  T. Bolch,et al.  Importance and vulnerability of the world’s water towers , 2019, Nature.

[13]  A. Shepherd,et al.  Ice Sheet Elevation Change in West Antarctica From Ka‐Band Satellite Radar Altimetry , 2019, Geophysical Research Letters.

[14]  A. Hall,et al.  An emergent constraint on future Arctic sea-ice albedo feedback , 2019, Nature Climate Change.

[15]  E. Berthier,et al.  Two decades of glacier mass loss along the Andes , 2019, Nature Geoscience.

[16]  N. Eckert,et al.  Brief communication: Ad hoc estimation of glacier contributions to sea-level rise from the latest glaciological observations , 2019, The Cryosphere.

[17]  J. Screen,et al.  Minimal influence of reduced Arctic sea ice on coincident cold winters in mid-latitudes , 2019, Nature Climate Change.

[18]  Marcus E. Engdahl,et al.  Trends in Antarctic Ice Sheet Elevation and Mass , 2019, Geophysical research letters.

[19]  E. Berthier,et al.  South American Andes elevation changes from 2000 to 2018, links to GeoTIFFs , 2019 .

[20]  C. L. Parkinson,et al.  A 40-y record reveals gradual Antarctic sea ice increases followed by decreases at rates far exceeding the rates seen in the Arctic , 2019, Proceedings of the National Academy of Sciences.

[21]  Bert Wouters,et al.  Global Glacier Mass Loss During the GRACE Satellite Mission (2002-2016) , 2019, Front. Earth Sci..

[22]  Eric Rignot,et al.  Forty-six years of Greenland Ice Sheet mass balance from 1972 to 2018 , 2019, Proceedings of the National Academy of Sciences.

[23]  N. Eckert,et al.  Global glacier mass changes and their contributions to sea-level rise from 1961 to 2016 , 2019, Nature.

[24]  M. Huss,et al.  A consensus estimate for the ice thickness distribution of all glaciers on Earth , 2019, Nature Geoscience.

[25]  Elizabeth D. Keller,et al.  Global environmental consequences of twenty-first-century ice-sheet melt , 2019, Nature.

[26]  N. Golledge,et al.  Global environmental consequences of twenty-first-century ice-sheet melt , 2019, Nature.

[27]  Michael Bevis,et al.  Accelerating changes in ice mass within Greenland, and the ice sheet’s sensitivity to atmospheric forcing , 2019, Proceedings of the National Academy of Sciences.

[28]  M. Phillips,et al.  Permafrost is warming at a global scale , 2019, Nature Communications.

[29]  Pedro Skvarca,et al.  Constraining glacier elevation and mass changes in South America , 2019, Nature Climate Change.

[30]  Eric Rignot,et al.  Four decades of Antarctic Ice Sheet mass balance from 1979–2017 , 2019, Proceedings of the National Academy of Sciences.

[31]  A. Dai,et al.  Arctic amplification is caused by sea-ice loss under increasing CO2 , 2019, Nature Communications.

[32]  T. Maksym.  Arctic and Antarctic Sea Ice Change: Contrasts, Commonalities, and Causes. , 2019, Annual review of marine science.

[33]  Xiaosong Yang,et al.  Natural variability of Southern Ocean convection as a driver of observed climate trends , 2018, Nature Climate Change.

[34]  Julienne Stroeve,et al.  Changing state of Arctic sea ice across all seasons , 2018, Environmental Research Letters.

[35]  P. Skvarca,et al.  Annual glacier elevation change rate raster dataset, South American Andes 2000 and 2011-2015 , 2018 .

[36]  Eric Rignot,et al.  Global sea-level budget 1993–present , 2018, Earth System Science Data.

[37]  Marcus E. Engdahl,et al.  25 years of elevation changes of the Greenland Ice Sheet from ERS, Envisat, and CryoSat-2 radar altimetry , 2018 .

[38]  H. Fricker,et al.  Trends and connections across the Antarctic cryosphere , 2018, Nature.

[39]  Eric Rignot,et al.  Mass balance of the Antarctic Ice Sheet from 1992 to 2017 , 2018, Nature.

[40]  Matthias Huss,et al.  Global-scale hydrological response to future glacier mass loss , 2018, Nature Climate Change.

[41]  A. Muir,et al.  CryoSat-2 swath interferometric altimetry for mapping ice elevation and elevation change , 2017, Advances in Space Research.

[42]  Andrew Shepherd,et al.  Estimating Arctic sea ice thickness and volume using CryoSat-2 radar altimeter data , 2017, Advances in Space Research.

[43]  L Mayer,et al.  BedMachine v3: Complete Bed Topography and Ocean Bathymetry Mapping of Greenland From Multibeam Echo Sounding Combined With Mass Conservation , 2017, Geophysical research letters.

[44]  S. Lhermitte,et al.  Modelling the climate and surface mass balance of polar ice sheets using RACMO2 – Part 2: Antarctica (1979–2016) , 2017 .

[45]  S. Lhermitte,et al.  Modelling the climate and surface mass balance of polar ice sheets using RACMO2 – Part 1: Greenland (1958–2016) , 2017 .

[46]  Sean Vitousek,et al.  Doubling of coastal flooding frequency within decades due to sea-level rise , 2017, Scientific Reports.

[47]  I. Joughin,et al.  Increased ice flow in Western Palmer Land linked to ocean melting , 2017 .

[48]  A. Shepherd,et al.  Surface elevation change and mass balance of Icelandic ice caps derived from swath mode CryoSat‐2 altimetry , 2016 .

[49]  T. Shepherd,et al.  Nonlinear response of mid-latitude weather to the changing Arctic , 2016 .

[50]  G. Williams,et al.  A review of recent changes in Southern Ocean sea ice, their drivers and forcings , 2016 .

[51]  Willem Jan van de Berg,et al.  A high‐resolution record of Greenland mass balance , 2016 .

[52]  Cecilia M. Bitz,et al.  Antarctic sea-ice expansion between 2000 and 2014 driven by tropical Pacific decadal climate variability , 2016 .

[53]  Thomas W. N. Haine,et al.  Freshwater and its role in the Arctic Marine System: Sources, disposition, storage, export, and physical and biogeochemical consequences in the Arctic and global oceans , 2016 .

[54]  Matthew E. Pritchard,et al.  Outlet glacier response to the 2012 collapse of the Matusevich Ice Shelf, Severnaya Zemlya, Russian Arctic , 2015 .

[55]  S. Rahmstorf,et al.  Exceptional twentieth-century slowdown in Atlantic Ocean overturning circulation , 2015 .

[56]  Fernando S. Paolo,et al.  Volume loss from Antarctic ice shelves is accelerating , 2015, Science.

[57]  S. Solomon,et al.  Antarctic Ocean and Sea Ice Response to Ozone Depletion: A Two-Time-Scale Problem , 2015 .

[58]  David Parkes,et al.  Attribution of global glacier mass loss to anthropogenic and natural causes , 2014, Science.

[59]  Timo Vihma,et al.  Effects of Arctic Sea Ice Decline on Weather and Climate: A Review , 2014, Surveys in Geophysics.

[60]  Eric Rignot,et al.  Sustained increase in ice discharge from the Amundsen Sea Embayment, West Antarctica, from 1973 to 2013 , 2014, Geophysical Research Letters.

[61]  Ian Eisenman,et al.  Observational determination of albedo decrease caused by vanishing Arctic sea ice , 2014, Proceedings of the National Academy of Sciences.

[62]  K. Rode,et al.  Variation in the response of an Arctic top predator experiencing habitat loss: feeding and reproductive ecology of two polar bear populations , 2014, Global change biology.

[63]  Myoung-Jong Noh,et al.  An improved mass budget for the Greenland ice sheet , 2013 .

[64]  M. Huss.  Density assumptions for converting geodetic glacier volume change to mass change , 2013 .

[65]  M. R. van den Broeke,et al.  A Reconciled Estimate of Glacier Contributions to Sea Level Rise: 2003 to 2009 , 2013, Science.

[66]  Bert Wouters,et al.  Important role for ocean warming and increased ice-shelf melt in Antarctic sea-ice expansion , 2013 .

[67]  T. Scambos,et al.  Climate‐Induced Ice Shelf Disintegration in the Antarctic Peninsula , 2013 .

[68]  Malcolm Davidson,et al.  CryoSat‐2 estimates of Arctic sea ice thickness and volume , 2013 .

[69]  L. Copland,et al.  Volume and area changes of the Milne Ice Shelf, Ellesmere Island, Nunavut, Canada, since 1950 , 2012 .

[70]  Ian Joughin,et al.  Ice-Sheet Response to Oceanic Forcing , 2012, Science.

[71]  Bo Sun,et al.  Bedmap2: improved ice bed, surface and thickness datasets for Antarctica , 2012 .

[72]  S. Vavrus,et al.  Evidence linking Arctic amplification to extreme weather in mid‐latitudes , 2012 .

[73]  I. Joughin,et al.  21st-Century Evolution of Greenland Outlet Glacier Velocities , 2011, Science.

[74]  Robert S. Anderson,et al.  Sea ice loss enhances wave action at the Arctic coast , 2011 .

[75]  S. Jacobs,et al.  Stronger ocean circulation and increased melting under Pine Island Glacier ice shelf , 2011 .

[76]  Ron Kwok,et al.  Uncertainty in modeled Arctic sea ice volume , 2011 .

[77]  Sebastian B. Simonsen,et al.  Mass balance of the Greenland ice sheet (2003–2008) from ICESat data – the impact of interpolation, sampling and firn density , 2011 .

[78]  Duncan J. Wingham,et al.  Recent loss of floating ice and the consequent sea level contribution , 2010 .

[79]  I. Simmonds,et al.  The central role of diminishing sea ice in recent Arctic temperature amplification , 2010, Nature.

[80]  D. Vaughan,et al.  Overview of areal changes of the ice shelves on the Antarctic Peninsula over the past 50 years , 2009 .

[81]  D. Perovich,et al.  Loss of sea ice in the Arctic. , 2009, Annual review of marine science.

[82]  David M. Holland,et al.  Acceleration of Jakobshavn Isbræ triggered by warm subsurface ocean waters , 2008 .

[83]  Stephen F. Ackley,et al.  Thickness distribution of Antarctic sea ice , 2008 .

[84]  A. Vieli,et al.  Causes of pre-collapse changes of the Larsen B ice shelf: Numerical modelling and assimilation of satellite observations , 2007 .

[85]  R. Nerem,et al.  Recent Greenland Ice Mass Loss by Drainage System from Satellite Gravity Observations , 2006, Science.

[86]  S. McCallum,et al.  Stability of the Larsen B ice shelf on the Antarctic Peninsula during the Holocene epoch , 2005, Nature.

[87]  A. Shepherd,et al.  Warm ocean is eroding West Antarctic Ice Sheet , 2004 .

[88]  Eric Rignot,et al.  Accelerated ice discharge from the Antarctic Peninsula following the collapse of Larsen B ice shelf , 2004 .

[89]  T. Scambos,et al.  Glacier acceleration and thinning after ice shelf collapse in the Larsen B embayment, Antarctica , 2004 .

[90]  P. Skvarca,et al.  Larsen Ice Shelf Has Progressively Thinned , 2003, Science.

[91]  John Turner,et al.  Recent Rapid Regional Climate Warming on the Antarctic Peninsula , 2003 .

[92]  D. A. Rothrock,et al.  Modeling Global Sea Ice with a Thickness and Enthalpy Distribution Model in Generalized Curvilinear Coordinates , 2003 .

[93]  Richard A. Wood,et al.  Global Climatic Impacts of a Collapse of the Atlantic Thermohaline Circulation , 2002 .

[94]  J. Magnuson,et al.  Historical trends in lake and river ice cover in the northern hemisphere , 2000, Science.

[95]  Donald J. Cavalieri,et al.  Deriving long‐term time series of sea ice cover from satellite passive‐microwave multisensor data sets , 1999 .

[96]  H. Hellmer,et al.  Antarctic Ice Sheet melting in the southeast Pacific , 1996 .

[97]  S. Plummer,et al.  Spatially and temporally resolved ice loss in High Mountain Asia and the Gulf of Alaska observed by CryoSat-2 swath altimetry , 2021 .

[98]  P. Holmlund,et al.  Historically unprecedented global glacier decline in the early 21st century , 2015 .

[99]  Ian M. Howat,et al.  Synchronous retreat and acceleration of southeast Greenland outlet glaciers 2000–06: ice dynamics and coupling to climate , 2008 .

[100]  S. Jacobs,et al.  Melting of ice shelves and the mass balance of Antarctica , 1992, Journal of Glaciology.

[101]  J. Weertman,et al.  Stability of the Junction of an Ice Sheet and an Ice Shelf , 1974, Journal of Glaciology.