Ice Sheets

Oceans
This indicator examines the balance between snow accumulation and melting in the ice sheets that cover Greenland and Antarctica.

Figures

Figure 1. Cumulative Mass Balance of Greenland and Antarctica, 1992–2023

Data sources: Otosaka et al., 2023;3 NASA, 20245
Web update: June 2024

This figure shows the cumulative change in mass in the ice sheets of Greenland and Antarctica since 1992. The dark “combined” lines are based on more than 20 different studies that have been combined for each region. Shading shows the uncertainty estimates from the various data sets that feed into the combined average. The two “NASA JPL” lines have been added to show results from one commonly cited analysis, including seasonal variations. All estimates are centered at zero in 2002 to provide a consistent point of reference. Thus, a downward slope indicates a net loss of ice and snow. For reference, 1,000 billion metric tons is equal to about 260 cubic miles of ice—enough to raise sea level by about 3 millimeters.4

Show the data behind this figure
Year Greenland, combined Greenland, combined uncertainty Greenland, NASA JPL Antarctica, combined Antarctica, combined uncertainty Antarctica, NASA JPL
1992.00 459 16 459 33
1992.08 458 23 462 47
1992.17 457 28 464 57
1992.25 457 33 453 65
1992.33 456 36 443 71
1992.42 456 40 438 75
1992.50 455 43 433 79
1992.58 454 46 429 83
1992.67 454 49 424 87
1992.75 453 51 419 90
1992.83 452 54 415 94
1992.92 452 56 410 97
1993.00 450 59 403 100
1993.08 448 61 397 103
1993.17 446 63 390 106
1993.25 444 65 383 109
1993.33 441 67 377 112
1993.42 439 69 370 115
1993.50 437 71 363 118
1993.58 435 73 357 120
1993.67 433 75 350 123
1993.75 431 76 343 125
1993.83 429 78 337 128
1993.92 427 80 330 130
1994.00 418 81 323 133
1994.08 410 83 315 135
1994.17 401 85 308 137
1994.25 392 86 300 140
1994.33 383 88 293 142
1994.42 374 89 285 144
1994.50 365 91 278 146
1994.58 356 92 270 148
1994.67 348 94 263 150
1994.75 339 95 256 152
1994.83 330 96 248 154
1994.92 321 98 241 156
1995.00 317 100 233 158
1995.08 313 103 224 160
1995.17 310 105 216 162
1995.25 306 107 208 164
1995.33 302 110 200 166
1995.42 298 112 194 168
1995.50 295 114 188 170
1995.58 291 116 182 171
1995.67 287 119 176 173
1995.75 283 121 170 175
1995.83 280 123 164 177
1995.92 276 125 158 179
1996.00 277 127 153 180
1996.08 277 129 147 182
1996.17 278 131 141 184
1996.25 279 133 136 186
1996.33 279 135 130 187
1996.42 280 137 124 189
1996.50 281 138 121 191
1996.58 281 140 118 192
1996.67 282 142 115 194
1996.75 283 144 112 195
1996.83 283 146 109 197
1996.92 284 147 106 199
1997.00 283 149 105 200
1997.08 283 151 105 202
1997.17 283 153 104 203
1997.25 282 154 103 205
1997.33 282 156 103 206
1997.42 281 158 102 208
1997.50 281 160 101 209
1997.58 281 161 101 211
1997.67 280 163 100 212
1997.75 280 165 100 214
1997.83 280 166 99 215
1997.92 279 168 98 216
1998.00 275 169 97 218
1998.08 270 171 96 219
1998.17 266 172 95 221
1998.25 261 174 94 222
1998.33 256 176 93 224
1998.42 252 177 92 225
1998.50 247 179 91 226
1998.58 243 180 90 228
1998.67 238 182 89 229
1998.75 234 183 87 230
1998.83 229 184 86 232
1998.92 225 186 85 233
1999.00 219 187 84 235
1999.08 212 189 82 236
1999.17 206 190 80 237
1999.25 200 192 78 239
1999.33 194 193 77 240
1999.42 188 194 75 241
1999.50 181 196 73 243
1999.58 175 197 71 244
1999.67 169 198 70 245
1999.75 163 200 68 247
1999.83 157 201 66 248
1999.92 150 202 64 249
2000.00 148 204 62 250
2000.08 145 205 60 252
2000.17 143 206 58 253
2000.25 141 207 56 254
2000.33 138 209 54 255
2000.42 136 210 52 256
2000.50 133 211 50 258
2000.58 131 212 48 259
2000.67 128 213 46 260
2000.75 126 215 44 261
2000.83 123 216 42 262
2000.92 121 217 40 263
2001.00 114 218 38 265
2001.08 108 220 35 266
2001.17 102 221 32 267
2001.25 95 222 30 268
2001.33 89 223 27 269
2001.42 82 224 25 270
2001.50 76 226 22 271
2001.58 70 227 19 273
2001.67 63 228 17 274
2001.75 57 229 14 275
2001.83 50 230 11 276
2001.92 44 232 9 277
2002.00 33 233 7 278
2002.08 22 235 4 279
2002.17 11 237 2 280
2002.25 0 239 0 281
2002.29 0 0
2002.33 -11 241 -2 282
2002.35 67 18
2002.42 -22 243 -5 284
2002.50 -33 245 -8 285
2002.58 -44 246 -11 286
2002.62 -221 -60
2002.67 -55 248 -14 287
2002.71 -244 45
2002.75 -66 250 -17 288
2002.79 -211 62
2002.83 -77 252 -21 289
2002.87 -209 -69
2002.92 -88 253 -24 290
2002.96 -194 -47
2003.00 -100 255 -29 291
2003.04 -150 -47
2003.08 -113 256 -34 292
2003.12 -159 -199
2003.17 -125 258 -40 293
2003.20 -96 -169
2003.25 -138 259 -46 295
2003.29 -50 -41
2003.33 -150 260 -51 296
2003.36 -42 3
2003.42 -163 261 -57 297
2003.50 -176 262 -62 298
2003.54 -218 -127
2003.58 -188 263 -68 300
2003.62 -353 -122
2003.67 -201 264 -74 301
2003.71 -395 -130
2003.75 -216 265 -81 302
2003.79 -393 -48
2003.83 -230 266 -87 303
2003.87 -394 -107
2003.92 -244 267 -94 304
2003.96 -355 -273
2004.00 -258 268 -100 306
2004.02 -379 -330
2004.08 -272 269 -106 307
2004.13 -387 -488
2004.17 -287 270 -112 308
2004.21 -365 -336
2004.25 -302 271 -118 309
2004.29 -301 -384
2004.33 -318 273 -124 310
2004.37 -320 -154
2004.42 -333 274 -129 311
2004.46 -339 -186
2004.50 -349 275 -135 313
2004.54 -436 -311
2004.58 -365 276 -140 314
2004.62 -560 -166
2004.67 -380 277 -146 315
2004.71 -599 -161
2004.75 -396 278 -151 316
2004.79 -619 -86
2004.83 -411 279 -156 317
2004.87 -578 -226
2004.92 -427 280 -162 318
2004.96 -553 -305
2005.00 -442 281 -167 320
2005.04 -567 -390
2005.08 -458 282 -172 321
2005.12 -545 -454
2005.17 -474 283 -176 322
2005.20 -500 -404
2005.25 -491 284 -181 323
2005.29 -492 -250
2005.33 -507 285 -185 324
2005.37 -457 -227
2005.42 -524 286 -189 325
2005.46 -504 -203
2005.50 -541 287 -194 326
2005.54 -632 -158
2005.58 -558 288 -198 327
2005.62 -820 -209
2005.67 -575 289 -203 328
2005.71 -886 -112
2005.75 -592 290 -208 329
2005.79 -878 -106
2005.83 -609 291 -213 330
2005.87 -875 -61
2005.92 -625 292 -219 331
2005.96 -825 -159
2006.00 -642 293 -225 332
2006.04 -849 -223
2006.08 -659 294 -231 333
2006.12 -801 -316
2006.17 -677 295 -238 334
2006.20 -781 -182
2006.25 -695 296 -244 336
2006.29 -805 -157
2006.33 -715 297 -251 337
2006.37 -793 -77
2006.42 -735 298 -257 338
2006.45 -806 -49
2006.50 -756 299 -264 339
2006.54 -893 -99
2006.58 -776 300 -271 340
2006.62 -1,020 -13
2006.67 -796 301 -279 341
2006.71 -1,082 -22
2006.75 -817 302 -287 342
2006.79 -1,067 -96
2006.83 -836 303 -295 343
2006.87 -1,093 -88
2006.92 -856 304 -303 344
2006.96 -1,102 -233
2007.00 -875 305 -312 345
2007.04 -1,071 -436
2007.08 -895 306 -322 346
2007.12 -1,029 -427
2007.17 -915 307 -331 347
2007.20 -1,038 -359
2007.25 -935 308 -341 348
2007.29 -1,026 -335
2007.33 -956 309 -351 349
2007.37 -1,013 -179
2007.42 -977 310 -360 350
2007.45 -1,032 -190
2007.50 -997 311 -370 351
2007.54 -1,162 -269
2007.58 -1,018 311 -379 352
2007.62 -1,358 -232
2007.67 -1,039 312 -389 353
2007.71 -1,421 -159
2007.75 -1,059 313 -399 354
2007.79 -1,448 -247
2007.83 -1,079 314 -408 355
2007.87 -1,423 -438
2007.92 -1,099 315 -418 356
2007.96 -1,365 -520
2008.00 -1,119 316 -427 357
2008.04 -1,326 -727
2008.08 -1,139 317 -437 358
2008.12 -1,345 -605
2008.17 -1,159 318 -446 359
2008.21 -1,291 -738
2008.25 -1,179 319 -455 360
2008.29 -1,308 -562
2008.33 -1,199 319 -464 362
2008.37 -1,324 -472
2008.42 -1,219 320 -473 363
2008.46 -1,328 -555
2008.50 -1,240 321 -482 364
2008.54 -1,475 -650
2008.58 -1,260 322 -491 365
2008.62 -1,634 -603
2008.67 -1,281 323 -500 366
2008.71 -1,697 -446
2008.75 -1,301 324 -509 368
2008.79 -1,687 -534
2008.83 -1,321 325 -519 369
2008.87 -1,614 -520
2008.92 -1,340 326 -529 370
2008.96 -1,542 -624
2009.00 -1,360 327 -538 371
2009.04 -1,523 -705
2009.08 -1,380 328 -547 373
2009.12 -1,568 -679
2009.17 -1,400 328 -556 374
2009.20 -1,567 -615
2009.25 -1,421 330 -564 375
2009.29 -1,547 -580
2009.33 -1,443 331 -573 376
2009.37 -1,530 -554
2009.42 -1,465 332 -582 378
2009.46 -1,539 -539
2009.50 -1,488 333 -591 379
2009.54 -1,648 -438
2009.58 -1,510 334 -600 380
2009.62 -1,856 -470
2009.67 -1,533 335 -610 381
2009.71 -1,910 -483
2009.75 -1,555 336 -619 383
2009.79 -1,887 -537
2009.83 -1,579 337 -629 384
2009.87 -1,867 -524
2009.92 -1,603 338 -639 385
2009.96 -1,843 -632
2010.00 -1,629 339 -650 387
2010.04 -1,846 -801
2010.08 -1,654 340 -662 388
2010.12 -1,828 -807
2010.17 -1,680 341 -674 389
2010.20 -1,816 -689
2010.25 -1,707 341 -685 390
2010.29 -1,840 -759
2010.33 -1,733 342 -696 392
2010.37 -1,807 -781
2010.42 -1,760 343 -707 393
2010.45 -1,914 -794
2010.50 -1,787 344 -718 394
2010.54 -2,089 -997
2010.58 -1,814 345 -731 395
2010.62 -2,282 -927
2010.67 -1,841 345 -744 396
2010.71 -2,381 -847
2010.75 -1,868 346 -757 397
2010.79 -2,343 -880
2010.83 -1,895 347 -769 398
2010.87 -2,362 -901
2010.92 -1,921 348 -782 399
2010.95 -2,345 -914
2011.00 -1,948 349 -797 400
2011.08 -1,975 350 -812 401
2011.13 -2,324 -1,002
2011.17 -2,003 351 -827 402
2011.20 -2,309 -1,017
2011.25 -2,030 352 -841 403
2011.29 -2,305 -1,030
2011.33 -2,058 353 -855 403
2011.37 -2,324 -963
2011.42 -2,087 354 -869 404
2011.50 -2,115 355 -883 405
2011.54 -2,515 -914
2011.58 -2,143 356 -898 406
2011.62 -2,707 -930
2011.67 -2,171 357 -912 407
2011.71 -2,766 -841
2011.75 -2,199 358 -926 408
2011.79 -2,788 -887
2011.83 -2,788 -882
2011.83 -2,227 359 -940 409
2011.92 -2,255 360 -953 410
2012.00 -2,281 361 -2,727 -966 411 -1,149
2012.04 -2,738 -1,077
2012.08 -2,308 362 -979 412
2012.12 -2,720 -1,141
2012.17 -2,335 363 -992 413
2012.21 -2,675 -1,120
2012.25 -2,362 364 -1,005 414
2012.26 -2,664 -1,059
2012.33 -2,390 365 -1,020 415
2012.42 -2,418 367 -1,034 416
2012.46 -2,693 -1,095
2012.50 -2,444 368 -1,048 417
2012.54 -2,923 -1,063
2012.58 -2,470 369 -1,063 418
2012.62 -3,231 -984
2012.67 -2,496 370 -1,077 419
2012.70 -3,332 -951
2012.75 -2,521 371 -1,092 420
2012.83 -2,546 372 -1,106 420
2012.88 -3,267 -1,074
2012.92 -2,569 374 -1,121 421
2012.96 -3,254 -1,119
2013.00 -2,587 375 -1,137 422
2013.04 -3,250 -1,288
2013.08 -2,604 376 -1,153 423
2013.12 -3,243 -1,395
2013.17 -2,622 377 -1,168 424
2013.25 -2,641 378 -1,184 425
2013.30 -3,239 -1,139
2013.33 -2,659 379 -1,199 425
2013.37 -3,204 -1,240
2013.42 -2,677 380 -1,215 426
2013.46 -3,185 -1,249
2013.50 -2,695 381 -1,230 427
2013.54 -3,297 -1,214
2013.58 -2,713 382 -1,245 428
2013.67 -2,730 383 -1,261 429
2013.75 -2,748 384 -1,277 430
2013.79 -3,362 -1,304
2013.83 -2,764 385 -1,293 431
2013.87 -3,361 -1,350
2013.92 -2,781 386 -1,309 432
2013.96 -3,349 -1,402
2014.00 -2,796 387 -1,325 432
2014.02 -3,334 -1,511
2014.08 -2,810 388 -1,342 433
2014.17 -2,825 388 -1,359 434
2014.20 -3,282 -1,619
2014.25 -2,840 389 -1,375 435
2014.29 -3,271 -1,537
2014.33 -2,855 390 -1,392 436
2014.37 -3,269 -1,444
2014.42 -2,870 391 -1,408 436
2014.45 -3,309 -1,489
2014.50 -2,885 391 -1,425 437
2014.58 -2,901 392 -1,442 438
2014.62 -3,593 -1,539
2014.67 -2,917 393 -1,459 439
2014.71 -3,629 -1,367
2014.75 -2,932 393 -1,476 439
2014.79 -3,614 -1,455
2014.83 -2,948 394 -1,493 440
2014.88 -3,609 -1,531
2014.92 -2,963 395 -1,509 441
2015.00 -2,981 396 -1,521 442
2015.06 -3,525 -1,833
2015.08 -2,995 396 -1,532 443
2015.12 -3,531 -1,909
2015.17 -3,010 397 -1,543 443
2015.20 -3,486 -1,874
2015.25 -3,026 398 -1,554 444
2015.29 -3,477 -1,853
2015.32 -3,473 -1,782
2015.33 -3,041 398 -1,565 445
2015.42 -3,056 399 -1,576 446
2015.50 -3,072 400 -1,586 447
2015.53 -3,660 -1,752
2015.58 -3,088 401 -1,596 448
2015.62 -3,793 -1,902
2015.67 -3,103 401 -1,607 449
2015.70 -3,833 -1,853
2015.75 -3,119 402 -1,617 450
2015.83 -3,134 403 -1,627 451
2015.92 -3,149 404 -1,637 452
2015.98 -3,774 -1,898
2016.00 -3,163 404 -1,644 453
2016.04 -3,720 -1,920
2016.08 -3,176 405 -1,650 454
2016.12 -3,742 -1,995
2016.17 -3,190 406 -1,656 455
2016.21 -3,742 -1,931
2016.25 -3,205 406 -1,662 455
2016.33 -3,219 407 -1,667 456
2016.38 -3,709 -1,799
2016.42 -3,234 408 -1,673 457
2016.46 -3,705 -1,779
2016.50 -3,248 408 -1,678 458
2016.54 -3,879 -1,664
2016.58 -3,263 409 -1,683 459
2016.64 -4,131 -1,617
2016.67 -3,277 410 -1,688 460
2016.75 -3,291 410 -1,692 461
2016.83 -3,305 411 -1,697 462
2016.91 -4,005 -1,682
2016.92 -3,319 412 -1,701 463
2016.98 -4,070 -1,595
2017.00 -3,326 412 -1,708 464
2017.06 -4,022 -1,618
2017.08 -3,333 413 -1,716 465
2017.17 -3,340 414 -1,723 466
2017.25 -3,347 414 -4,015 -1,731 467 -1,948
2017.31 -3,977 -1,865
2017.33 -3,354 415 -1,736 468
2017.36 -3,969 -1,827
2017.42 -3,362 415 -1,741 469
2017.44 -4,001 -1,835
2017.50 -3,369 416 -1,746 470
2017.58 -3,377 416 -1,752 471
2017.67 -3,384 417 -1,758 472
2017.75 -3,391 417 -1,765 473
2017.83 -3,398 418 -1,771 474
2017.92 -3,405 418 -1,778 475
2018.00 -3,415 419 -1,791 476
2018.08 -3,425 420 -1,804 477
2018.17 -3,436 420 -1,816 478
2018.25 -3,448 421 -1,828 479
2018.33 -3,460 422 -1,840 480
2018.42 -3,472 423 -1,853 481
2018.45 -4,042 -2,011
2018.50 -3,484 424 -1,865 482
2018.52 -4,071 -2,039
2018.58 -3,505 425 -1,882 483
2018.67 -3,525 427 -1,899 484
2018.75 -3,546 428 -1,917 486
2018.83 -4,261 -2,182
2018.83 -3,568 429 -1,935 487
2018.87 -4,226 -2,139
2018.92 -3,591 430 -1,953 488
2018.96 -4,202 -2,279
2019.00 -3,629 431 -1,972 489
2019.04 -4,207 -2,396
2019.08 -3,665 432 -1,986 491
2019.12 -4,242 -2,456
2019.17 -3,703 433 -2,000 492
2019.20 -4,256 -2,403
2019.25 -3,740 434 -2,013 494
2019.29 -4,240 -2,369
2019.33 -3,777 435 -2,027 495
2019.37 -4,196 -2,210
2019.42 -3,814 435 -2,040 497
2019.45 -4,271 -2,266
2019.50 -3,851 436 -2,054 498
2019.54 -4,463 -2,128
2019.58 -3,888 437 -2,067 500
2019.62 -4,708 -2,290
2019.67 -3,925 438 -2,081 502
2019.71 -4,815 -2,333
2019.75 -3,962 439 -2,094 503
2019.79 -4,808 -2,315
2019.83 -3,999 439 -2,108 505
2019.87 -4,738 -2,324
2019.92 -4,036 440 -2,121 506
2019.96 -4,736 -2,431
2020.00 -4,073 441 -2,134 508
2020.04 -4,794 -2,675
2020.08 -4,106 442 -2,142 510
2020.12 -4,786 -2,778
2020.17 -4,138 444 -2,149 512
2020.21 -4,788 -2,699
2020.25 -4,171 445 -2,156 514
2020.29 -4,756 -2,576
2020.33 -4,204 447 -2,163 516
2020.37 -4,731 -2,454
2020.42 -4,237 448 -2,170 518
2020.46 -4,770 -2,396
2020.50 -4,269 450 -2,178 520
2020.54 -4,903 -2,447
2020.58 -4,302 451 -2,185 522
2020.62 -5,000 -2,408
2020.67 -4,335 452 -2,192 524
2020.71 -5,015 -2,470
2020.75 -4,367 454 -2,199 526
2020.79 -4,949 -2,533
2020.83 -4,400 455 -2,207 528
2020.87 -4,937 -2,601
2020.92 -4,433 457 -2,214 530
2020.96 -4,943 -2,648
2021.04 -4,916 -2,860
2021.12 -4,941 -2,648
2021.20 -4,922 -2,676
2021.29 -4,883 -2,460
2021.37 -4,930 -2,488
2021.46 -4,918 -2,661
2021.54 -4,962 -2,672
2021.62 -5,111 -2,612
2021.71 -5,160 -2,699
2021.79 -5,203 -2,501
2021.87 -5,199 -2,739
2021.96 -5,156 -2,644
2022.04 -5,127 -2,737
2022.12 -5,115 -2,696
2022.20 -5,086 -2,620
2022.29 -5,099 -2,381
2022.37 -5,092 -2,286
2022.45 -5,075 -2,307
2022.54 -5,178 -2,416
2022.62 -5,293 -2,370
2022.71 -5,341 -2,354
2022.79 -5,329 -2,409
2022.87 -5,251 -2,341
2022.96 -5,205 -2,341
2023.04 -5,305 -2,410
2023.12 -5,307 -2,460
2023.20 -5,252 -2,362
2023.29 -5,268 -2,151
2023.37 -5,247 -2,297
2023.45 -5,218 -2,298

Key Points

  • Since 1992, Greenland and Antarctica have both lost ice overall (see Figure 1), with Greenland losing an average of about 175 billion metric tons of ice per year and Antarctica losing more than 90 billion per year.
  • The total amount of ice lost by Greenland and Antarctica from 1992 to 2020 was enough to raise sea level worldwide by an average of three-quarters of an inch or more.3 By comparison, global average sea level increased by about 3 inches overall during this period (see the Sea Level indicator).
  • Ice sheets naturally fluctuate with seasonal variations in temperature, precipitation, and other factors. The NASA JPL data points in Figure 1 show these types of seasonal patterns, particularly for Greenland. With nearly three decades of data, though, Figure 1 shows that the overall shrinking of the ice sheets far exceeds seasonal and year-to-year variations.
  • Observations of ice sheets losing mass are consistent with trends in small glaciers (see the Glaciers indicator) as well as warming trends in global temperatures during this period (see the U.S. and Global Temperature indicator).

Background

Ice sheets are large bodies of ice on land that cover hundreds of thousands of square miles on Greenland and Antarctica. Greenland’s ice sheet reaches more than 1 mile thick on average in the interior and contains an estimated 700,000 cubic miles of ice, while Antarctica’s ice is nearly 3 miles thick in some places, with a volume of about 7 million cubic miles.1 Together, these ice sheets hold nearly 70 percent of the world’s fresh water. Some of this ice has been in place for more than 1 million years.

Ice sheets accumulate snowfall—just like small glaciers (see the Glaciers indicator) but at a larger scale. Over time, this snow becomes compacted into layers of ice, and the weight of this ice causes it to flow downhill and outward toward the ocean. When an ice sheet is in equilibrium, new snow accumulation is balanced by melting at the surface, runoff, and calving (ice breaking off to form icebergs) at the ocean.

A warmer climate affects ice sheets in several ways. The most evident impact observed to date is a loss of ice due to warmer air and ocean waters. Warmer air causes the ice to melt more quickly and flow more rapidly to the sea, especially in low-elevation regions near the edges of the ice sheets. Warmer ocean waters melt the edge and base of the ice sheet and accelerate the process of calving. In addition, warmer ocean waters weaken the floating ice shelves that form in key places along the coast, especially in Antarctica. These ice shelves help to hold back the flow of ice on land, so as ice shelves shrink or disappear, ice from the ice sheet can flow into the ocean more quickly. Some of the losses are offset, because warmer air allows very cold interior regions in Greenland and Antarctica to receive more snowfall. Overall, though, both ice sheets are experiencing a net loss of ice. Ultimately, as the ice sheets shrink, the water they add to the ocean raises sea level around the world (see the Sea Level indicator). Melting of Greenland and Antarctica’s ice sheets accounted for about one-third of observed global sea level rise between 2006 and 2015.2 Thus, ice sheets are important indicators not only because of their sensitivity to changes in climate, but also for their role in global sea level rise.

About the Indicator

Because Greenland and Antarctica are so large and remote, satellite instruments offer the most effective way to measure changes in their ice sheets. Scientists have used three main measurement techniques to do this:

  • Measuring the height of the ice sheet surface, relative to sea level. This technique is called altimetry and it typically uses radar or laser instruments.
  • Measuring changes in the weight of the ice on Greenland and Antarctica, based on slight variations in the Earth’s gravitational field caused by changes in the density of the Earth’s crust and the amount of ice or water that may be piled on top of that crust. This technique uses a pair of satellites called the GRACE Mission, which launched in 2002.
  • Using the “input-output” method, which combines various sources of information on ice accumulation (e.g., models of surface mass balance) and discharge into the ocean (e.g., based on radar, satellite images, and other data).

Estimates of the exact rate of ice gain or loss in Greenland and Antarctica vary depending on the measurement technique and the methods used to process the data. Each technique has advantages and disadvantages. Therefore, to get a more complete picture, scientists have combined many different estimates from a variety of organizations. This indicator offers a combined estimate from an international program called the Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE). IMBIE is supported by the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA). The IMBIE team combined 27 peer-reviewed estimates of ice sheet mass balance for Greenland and 23 for Antarctica, going back as far as 1992 and representing all three major techniques. Figure 1 represents the results from their combined averages.

Figure 1 also shows estimates from a specific analysis of GRACE data by NASA’s Jet Propulsion Laboratory (JPL). These data are shown for reference and comparison because NASA JPL is a widely cited, influential source, and because the results show seasonal patterns.

Indicator Notes

The relationship between climate change and ice sheet mass balance is complex, particularly in Antarctica, where large areas will continue to be too cold to experience appreciable surface melting, some areas may experience more snowfall that offsets the other effects of warming, and rates of ice loss can be heavily influenced by specific “tipping point” events such as the collapse of an ice shelf. Scientists who study Antarctica’s ice sheets often divide the continent into three main regions—East Antarctica, West Antarctica, and the Antarctic Peninsula—because each of these regions has distinct geological characteristics and weather patterns that influence their vulnerability to climate change.

Data are not available prior to 1992 for these two featured data sets. However, studies using other methods provide a longer historical perspective.6,7 Unlike smaller land ice features such as glaciers (see the Glaciers indicator), the vast ice sheets of Greenland and Antarctica do not have enough widespread, repeated measurements collected onsite to permit reliable estimates of changes in overall mass balance. This indicator presents results from multiple measurement methodologies for comparison and to expand the temporal coverage of the time series for ice sheet mass balance of Greenland and Antarctica. The NASA time series each have a gap from mid-2017 to mid-2018, reflecting the gap between the original GRACE satellite mission and the GRACE Follow On satellites that launched in 2018.

Data Sources

The IMBIE team and NASA JPL processed the data for Figure 1. The IMBIE data have been published at: http://imbie.org, along with documentation. The JPL data have been published on NASA’s “Vital Signs” website at: https://climate.nasa.gov/vital-signs/land-ice, along with documentation.

Technical Documentation

References

  1. NSIDC (National Snow and Ice Data Center). (2024). Ice sheets: Quick facts. Retrieved February 29, 2024, from https://nsidc.org/learn/parts-cryosphere/ice-sheets/ice-sheet-quick-facts
  2. IPCC (Intergovernmental Panel on Climate Change). (2019). Summary for policymakers. In The ocean and cryosphere in a changing climate: Special report of the Intergovernmental Panel on Climate Change. Cambridge University Press. https://doi.org/10.1017/9781009157964.001
  3. Otosaka, I. N., Shepherd, A., Ivins, E. R., Schlegel, N.-J., Amory, C., Van Den Broeke, M. R., Horwath, M., Joughin, I., King, M. D., Krinner, G., Nowicki, S., Payne, A. J., Rignot, E., Scambos, T., Simon, K. M., Smith, B. E., Sørensen, L. S., Velicogna, I., Whitehouse, P. L., … Wouters, B. (2023). Mass balance of the Greenland and Antarctic ice sheets from 1992 to 2020. Earth System Science Data, 15(4), 1597–1616. https://doi.org/10.5194/essd-15-1597-2023
  4. IPCC (Intergovernmental Panel on Climate Change). (2013). Climate change 2013—The physical science basis: Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (T. F. Stocker, D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, A. Boschung, A. Nauels, Y. Xia, V. Bex, & Midgley, Eds.). Cambridge University Press. www.ipcc.ch/report/ar5/wg1
  5. NASA (National Aeronautics and Space Administration). (2024). Vital signs: Ice sheets. Retrieved February 29, 2024, from https://climate.nasa.gov/vital-signs/ice-sheets
  6. Mouginot, J., Rignot, E., Bjørk, A. A., Van Den Broeke, M., Millan, R., Morlighem, M., Noël, B., Scheuchl, B., & Wood, M. (2019). Forty-six years of Greenland Ice Sheet mass balance from 1972 to 2018. Proceedings of the National Academy of Sciences, 116(19), 9239–9244. https://doi.org/10.1073/pnas.1904242116
  7. Rignot, E., Mouginot, J., Scheuchl, B., Van Den Broeke, M., Van Wessem, M. J., & Morlighem, M. (2019). Four decades of Antarctic Ice Sheet mass balance from 1979–2017. Proceedings of the National Academy of Sciences, 116(4), 1095–1103. https://doi.org/10.1073/pnas.1812883116

Text on this page is EPA’s own published wording (a U.S. Government work, not subject to domestic copyright), extracted from EPA’s published indicator page and verified paragraph by paragraph against the archived HTML. Data, chart code, and the full extraction pipeline are maintained in the ice-sheets repository, which this page reads its data from directly.

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