Evidence record

How high will the sea rise?

Every sentence on the exploration belongs to at least one claim below. Each says what kind of statement it is, what it rests on, what the evidence does not establish, and how far it was checked. Nothing here is a score, and none of it is a verdict on a belief or a theory.

Last checked 24 September 2026.

A judgement, not a fact: 12
Source checked: 36
Presented as open: 4
Partly checked: 2

If something here is wrong, misquoted, out of date or unfair, write to support@unknownoceans.com and give the claim number, which does not change.

What the question takes for granted

A question about a projection, not a measurement. The rise so far is measured; the rise to come is modelled, and the page separates the part of the range that can be projected with medium confidence from an upper tail that cannot be given a probability.

The sea will keep rising this century
Established
AR6 rates continued rise to 2100 virtually certain, whatever the scenario.
A single global number is the thing to ask for
Contested
The global mean is well defined, but coasts differ from it, and the page itself argues that the local number is the one that matters for planning.
The upper end can be given a probability
Open
AR6 says it cannot currently robustly quantify how likely the deeply uncertain ice-sheet processes are to raise sea level before 2100, which is why the 2.3 metres is a percentile held with low confidence.

How the question is labelled

Claim: The number with a tail

Kind: This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review: A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

The page’s title: the projection has a well-constrained middle and a long upper tail, which follows from claims 35 to 38.

Claim 1 · checked 24 September 2026 · AI-assisted audit

Claim: Sea level

Kind: Framing. Signposting. It asserts nothing a source could check.

The question

Claim: The central estimate for this century is well constrained.

Kind: This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review: A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

A judgement on the assessed likely ranges, which for a given scenario span roughly 0.3 to 0.4 metres and rest on processes projected with at least medium confidence.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Sea Level, p. 1216
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: relative to the period 1995–2014, GMSL will rise ... by 2100 between 0.38 [0.28 to 0.55, likely range] m (SSP1-1.9) and 0.77 [0.63 to 1.01, likely range] m (SSP5-8.5).
Context
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Box 9.4, p. 1308
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: because ‘likely’ implies an assessed likelihood of up to 16% that sea level rise by 2100 will be higher

What this does not establish

“Well constrained” is relative to the tail. The likely range still leaves an assessed chance of up to one in six of a higher rise.

Claim 3 · checked 24 September 2026 · AI-assisted audit

Claim: The upper end is not, and the reason is the ice sheets, Antarctica above all.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Sea Level, p. 1217
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Higher amounts of GMSL rise before 2100 could be caused by earlier-than-projected disintegration of marine ice shelves, the abrupt, widespread onset of marine ice sheet instability and marine ice cliff instability around Antarctica, and faster-than-projected changes in the surface mass balance and discharge from Greenland.
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.7, p. 1314
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: The largest uncertainties in future sea level and cryosphere change are related to the Greenland and Antarctic ice sheets
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Table 9.9, p. 1302
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Greenland 0.05 (0.00–0.09) 0.06 (0.01–0.10) 0.08 (0.04–0.13) 0.11 (0.07–0.16) 0.13 (0.09–0.18) 0.18 (0.09–0.59) Antarctica 0.10 (0.03–0.25) 0.11 (0.03–0.27) 0.11 (0.03–0.29) 0.11 (0.03–0.31) 0.12 (0.03–0.34) 0.19 (0.02–0.56)
Medians and likely ranges in metres for 2100 under SSP1-1.9 to SSP5-8.5; the last column is the low-confidence 17th to 83rd percentile range.
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.6, p. 1272
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: projections in which Antarctica contributes much more than the assessed ranges under sustained very high greenhouse gas emissions – that is, around 7–14 m to GMSL by 2300 (DeConto et al., 2021), cannot be ruled out

What this does not establish

By 2100 under the highest scenario, the low-confidence ranges for Greenland and Antarctica are similar in width; Antarctica’s share is widest in the medium-confidence projections and dominates beyond 2100.

Later work looked for

Crossref, 2021 on, "sea level projection 2100 ice sheet": no IPCC assessment has replaced AR6 (the Seventh Assessment is not yet published); nothing found that changes this.

Corrected

24 September 2026. Previously: “The upper end is not, and the reason is one ice sheet.” AR6 names Greenland as well as Antarctica among the processes that could push the rise above the likely range, and places the largest uncertainties in both ice sheets.

Claim 4 · checked 24 September 2026 · AI-assisted audit

Claim: Thermal expansion and melting glaciers are understood well enough to project.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Box 9.1, p. 1220
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Reference work
The source reads: There is high confidence in the understanding of processes causing thermosteric sea level change ... There is medium to high confidence in the understanding of processes leading to sea level contributions from glaciers
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Table 9.9, caption, p. 1302
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Unshaded cells represent processes in whose projections there is medium confidence.

Later work looked for

Crossref, 2021 on, "sea level projection 2100 ice sheet": no IPCC assessment has replaced AR6 (the Seventh Assessment is not yet published); nothing found that changes this.

Claim 5 · checked 24 September 2026 · AI-assisted audit

Claim: Antarctica is not: whether its marine-based ice can collapse rapidly is an open question

Kind: Open question. Something the page says is not known.
Review: Presented as open. The page says this is unresolved, and the review found that it is.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.4, p. 1269
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: MISI is a proposed self-reinforcing mechanism within marine ice sheets that lie on a bed that slopes down towards the interior of the ice sheet, whereby, in the absence of ice-shelf buttressing, the position of the grounding line is inherently unstable until reaching an upward sloping bed.
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.1, p. 1263
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: However, whether unstable WAIS retreat had begun, or was imminent, remained a critical uncertainty. New publications since SROCC have not substantially clarified this question.

Claim 6 · checked 24 September 2026 · AI-assisted audit

Claim: whose answer separates a manageable rise from an unmanageable one,

Kind: This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review: A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

The page’s judgement of what the difference between the projections with and without ice-cliff instability means, which reaches from a few metres to up to 16 metres by 2300 under the highest scenario.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Sea Level, p. 1217
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: By 2300, GMSL will rise between 0.3 m and 3.1 m under SSP1-2.6, between 1.7 m and 6.8 m under SSP5-8.5 in the absence of marine ice cliff instability, and by up to 16 m under SSP5-8.5 considering marine ice cliff instability (low confidence).

Claim 7 · checked 24 September 2026 · AI-assisted audit

Claim: and it cannot currently be ruled out.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Climate Change 2021: The Physical Science Basis (AR6 Working Group I)Summary for Policymakers, B.5.3
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Global mean sea level rise above the likely range – approaching 2 m by 2100 and 5 m by 2150 under a very high GHG emissions scenario (SSP5-8.5) (low confidence) – cannot be ruled out due to deep uncertainty in ice-sheet processes.
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.6, p. 1272
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: projections in which Antarctica contributes much more than the assessed ranges under sustained very high greenhouse gas emissions – that is, around 7–14 m to GMSL by 2300 (DeConto et al., 2021), cannot be ruled out
Context
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Box 9.4, p. 1308
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: we cannot currently robustly quantify the likelihood with which they can cause higher sea level rise before 2100

What this does not establish

Not ruled out is not likely: AR6 gives these outcomes low confidence and cannot robustly quantify their probability.

Later work looked for

Crossref, 2021 on, "sea level projection 2100 ice sheet": no IPCC assessment has replaced AR6 (the Seventh Assessment is not yet published); nothing found that changes this.

Claim 8 · checked 24 September 2026 · AI-assisted audit

Claim: The IPCC rates it virtually certain that the sea will keep rising through this century,

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Sea Level, p. 1216
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: It is virtually certain that GMSL will continue to rise until at least 2100, because all assessed contributors to GMSL are likely to virtually certain to continue contributing throughout this century.

Later work looked for

Crossref, 2021 on, "sea level projection 2100 ice sheet": no IPCC assessment has replaced AR6 (the Seventh Assessment is not yet published); nothing found that changes this.

Corrected

24 September 2026. Previously: “Sea level rise is often described as the most predictable consequence of a warming climate, and for most of the contributions that is true.” No source was found for the claim that sea level rise is often described as the most predictable consequence of warming. The sentence now says what the assessment itself says.

Claim 9 · checked 24 September 2026 · AI-assisted audit

Claim: and for most of the contributions the amount can be projected too.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Sea Level, p. 1216
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Considering only processes for which projections can be made with at least medium confidence ... These likely range projections do not include those ice-sheet-related processes that are characterized by deep uncertainty.
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Table 9.9, caption, p. 1302
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Unshaded cells represent processes in whose projections there is medium confidence.

What this does not establish

Projected with at least medium confidence, which is the IPCC’s threshold for its likely ranges, not a guarantee.

Later work looked for

Crossref, 2021 on, "sea level projection 2100 ice sheet": no IPCC assessment has replaced AR6 (the Seventh Assessment is not yet published); nothing found that changes this.

Claim 10 · checked 24 September 2026 · AI-assisted audit

Claim: The uncertainty is not spread evenly across the projection. It is concentrated in the ice sheets, above all in Antarctica, and it sits at the top of the range.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.7, p. 1314
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: The largest uncertainties in future sea level and cryosphere change are related to the Greenland and Antarctic ice sheets
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Sea Level, p. 1217
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Higher amounts of GMSL rise before 2100 could be caused by earlier-than-projected disintegration of marine ice shelves, the abrupt, widespread onset of marine ice sheet instability and marine ice cliff instability around Antarctica, and faster-than-projected changes in the surface mass balance and discharge from Greenland.
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Table 9.9, p. 1302
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Greenland 0.05 (0.00–0.09) 0.06 (0.01–0.10) 0.08 (0.04–0.13) 0.11 (0.07–0.16) 0.13 (0.09–0.18) 0.18 (0.09–0.59) Antarctica 0.10 (0.03–0.25) 0.11 (0.03–0.27) 0.11 (0.03–0.29) 0.11 (0.03–0.31) 0.12 (0.03–0.34) 0.19 (0.02–0.56)
Medians and likely ranges in metres for 2100 under SSP1-1.9 to SSP5-8.5; the last column is the low-confidence 17th to 83rd percentile range.
Qualifies
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.7, p. 1314
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Glacier inventory and projection uncertainty has been a significant source of past sea level budget uncertainty and remains a dominant uncertainty until mid-century.

What this does not establish

Glacier projections also carry large uncertainty until mid-century, which AR6 notes; the ice sheets lead after that.

Later work looked for

Crossref, 2021 on, "sea level projection 2100 ice sheet": no IPCC assessment has replaced AR6 (the Seventh Assessment is not yet published); nothing found that changes this.

Corrected

24 September 2026. Previously: “It is concentrated in one process, on one continent, and it sits at the top of the range.” AR6 attributes the largest uncertainties to both ice sheets and includes faster-than-projected change in Greenland in its high-end storyline.

Claim 11 · checked 24 September 2026 · AI-assisted audit

What is measured

Claim: What is measured

Kind: Framing. Signposting. It asserts nothing a source could check.

It is rising, and the rate is increasing

Claim: It is rising, and the rate is increasing

Kind: Observation. Something measured or seen, as the named source reports it.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Sea Level, p. 1216
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: GMSL rise has accelerated since the late 1960s, with an average rate of 2.3 [1.6 to 3.1] mm yr –1 over the period 1971–2018 increasing to 3.7 [3.2 to 4.2] mm yr –1 over the period 2006–2018

Later work looked for

Crossref, 2022 on, "global mean sea level rise acceleration satellite altimetry": later records continue the acceleration (Hamlington and others, 2024, "The rate of global sea level rise doubled during the past three decades"); nothing that changes the claim.

Claim 13 · checked 24 September 2026 · AI-assisted audit

Claim: Tide gauges and, since the early 1990s, satellite altimetry record a rise that has accelerated over the period of measurement.

Kind: Observation. Something measured or seen, as the named source reports it.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Sea Level, p. 1216
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: GMSL rise has accelerated since the late 1960s, with an average rate of 2.3 [1.6 to 3.1] mm yr –1 over the period 1971–2018 increasing to 3.7 [3.2 to 4.2] mm yr –1 over the period 2006–2018
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.6.1.1, p. 1287
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: the SROCC assessment on the acceleration of GMSL rise over the 20th century is maintained
Context
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.6.1.1, p. 1287
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: the GMSL change over the (pre-satellite) period 1901–1990 is assessed to be 0.12 [0.07 to 0.17, very likely range] m

What this does not establish

Tide gauge reconstructions of the global mean start in 1901, and AR6 dates the clearest acceleration from the late 1960s.

Later work looked for

Claim 14 · checked 24 September 2026 · AI-assisted audit

Claim: The two methods agree where they overlap,

Kind: Observation. Something measured or seen, as the named source reports it.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.6.1.2, p. 1287
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: For the common period of 1993–2010, the assessed rate of GMSL rise based on tide gauge reconstructions (3.19 [1.18 to 5.20] mm yr –1) is consistent with the assessment based on satellite altimetry (2.77 [2.26 to 3.28] mm yr –1), within the estimated uncertainties.

What this does not establish

Agreement is within wide uncertainties: the tide gauge rate for 1993 to 2010 has a range several times wider than the satellite rate.

Later work looked for

Claim 15 · checked 24 September 2026 · AI-assisted audit

Claim: which matters because they measure from different places:

Kind: This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review: A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

Two instruments with different reference frames agreeing is evidence that neither frame is producing the signal. Follows from claim 17.

Corrected

24 September 2026. Previously: “which matters because they fail in different ways.” The chapter describes the two methods by reference frame, not by their failure modes. The sentence now says what it describes.

Claim 16 · checked 24 September 2026 · AI-assisted audit

Claim: a tide gauge reads the sea against the land it stands on, a satellite reads it from space.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Box 9.1, p. 1220
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Reference work
The source reads: as measured by instruments that are fixed to the Earth’s surface (e.g., tide gauges) ... is the sea level change observed with instruments from space
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Box 9.1, p. 1221
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Reference work
The source reads: Vertical land motion is the change in height of the land surface or the sea floor

Later work looked for

How the method works; not a finding later work revises.

Claim 17 · checked 24 September 2026 · AI-assisted audit

Claim: The contributions can be added up independently: the ocean expands as it warms, glaciers lose mass, the Greenland and Antarctic ice sheets lose mass, and the water stored on land changes.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Box 9.1, p. 1220
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Reference work
The source reads: It is the sum of changes in ocean density (‘global mean thermosteric sea level change’) and changes in the ocean mass as a result of changes in the cryosphere or land-water storage (‘barystatic sea level change’).
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Cross-Chapter Box 9.1, p. 1285
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Measurement
The source reads: The assessed sum of the observed components indicates that GMSL very likely increased by 72 mm to 117 mm over the period 1971–2018 ... with the largest contributions from ocean thermal expansion (50%) and melting of ice sheets and glaciers (42%) ... the sea level budget is closed for this period

Later work looked for

How the method works; not a finding later work revises.

Corrected

24 September 2026. Previously: “the ocean expands as it warms, mountain glaciers lose mass, and the Greenland and Antarctic ice sheets lose mass.” The budget AR6 closes includes land-water storage, and its glacier term is all glaciers outside the ice sheets, not only mountain glaciers.

Claim 18 · checked 24 September 2026 · AI-assisted audit

Claim: The sum matches the measured total within its uncertainties,

Kind: Observation. Something measured or seen, as the named source reports it.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Cross-Chapter Box 9.1, p. 1285
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Measurement
The source reads: The assessed sum of the observed components indicates that GMSL very likely increased by 72 mm to 117 mm over the period 1971–2018 ... has a very likely range of 73–146 mm and, as a result, the sea level budget is closed for this period

What this does not establish

Closure is of very likely ranges that overlap (72 to 117 mm summed against 73 to 146 mm observed for 1971 to 2018), not of two identical numbers.

Later work looked for

Crossref, 2022 on, "sea level budget closure": later budget studies report closure within uncertainties; nothing that changes it.

Corrected

24 September 2026. Previously: “The sum matches the measured total,” The two totals agree as overlapping ranges, not exactly.

Claim 19 · checked 24 September 2026 · AI-assisted audit

Claim: which is a strong check on all of them.

Kind: This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review: A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

AR6 says the closure improves the quantification of the processes; “strong” is the page’s word.

Context
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Cross-Chapter Box 9.1, p. 1285
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: The sea level budget closure demonstrates improved quantification of the processes of observed GMSL change for this period relative to previous IPCC assessments

Claim 20 · checked 24 September 2026 · AI-assisted audit

It does not stop when emissions do

Claim: It does not stop when emissions do

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)FAQ 9.2, p. 1318
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Even if net zero emissions are reached, sea level rise will continue because the deep ocean will continue to warm and ice sheets will take time to catch up to the warming caused by past and present emissions

Later work looked for

Crossref, 2021 on, "sea level projection 2100 ice sheet": no IPCC assessment has replaced AR6 (the Seventh Assessment is not yet published); nothing found that changes this.

Claim 21 · checked 24 September 2026 · AI-assisted audit

Claim: The deep ocean takes centuries to warm through,

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Ocean heat content, p. 1214
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: The associated warming will likely continue until at least 2300, even for low-emissions scenarios, because of the slow circulation of the deep ocean.

Later work looked for

Crossref, 2021 on, "sea level projection 2100 ice sheet": no IPCC assessment has replaced AR6 (the Seventh Assessment is not yet published); nothing found that changes this.

Claim 22 · checked 24 September 2026 · AI-assisted audit

Claim: and ice sheets respond to a change in climate over centuries to millennia.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Sea Level, p. 1217
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Beyond 2100, GMSL will continue to rise for centuries due to continuing deep-ocean heat uptake and mass loss of the Greenland and Antarctic ice sheets, and will remain elevated for thousands of years (high confidence).
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.6, p. 1273
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: There is limited agreement about whether complete disintegration would eventually occur at this level of warming, but medium confidence this would take millennia.
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Box 9.4, p. 1308
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: the main uncertainty related to high-end sea level rise is ‘when’ rather than ‘if’ it arises: the upper limit of 1.01 m of likely sea level range by 2100 for the SSP5-8.5 scenario will be exceeded in any future warming scenario on time scales of centuries to millennia (high confidence)

Later work looked for

Crossref, 2021 on, "sea level projection 2100 ice sheet": no IPCC assessment has replaced AR6 (the Seventh Assessment is not yet published); nothing found that changes this.

Claim 23 · checked 24 September 2026 · AI-assisted audit

Claim: Sea level in 2300 depends on what happens this century,

Kind: What a model says. What a theory or model predicts or describes, which is not the same as what has been observed.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Sea Level, p. 1217
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: By 2300, GMSL will rise between 0.3 m and 3.1 m under SSP1-2.6, between 1.7 m and 6.8 m under SSP5-8.5 in the absence of marine ice cliff instability, and by up to 16 m under SSP5-8.5 considering marine ice cliff instability (low confidence).
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)FAQ 9.2, p. 1318
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: The accumulated total emissions of greenhouse gases over the upcoming decades will play a big role beyond 2050, especially in determining where sea level rise and ice-sheet changes eventually level off.
Qualifies
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.7, p. 1314
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: After 2150, limited agreement causes us to consider all projections as low confidence.

What this does not establish

AR6 holds every projection after 2150 with low confidence.

Later work looked for

Crossref, 2021 on, "sea level projection 2100 ice sheet": no IPCC assessment has replaced AR6 (the Seventh Assessment is not yet published); nothing found that changes this.

Claim 24 · checked 24 September 2026 · AI-assisted audit

Claim: and continues rising afterwards under every scenario.

Kind: What a model says. What a theory or model predicts or describes, which is not the same as what has been observed.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Sea Level, p. 1217
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Beyond 2100, GMSL will continue to rise for centuries due to continuing deep-ocean heat uptake and mass loss of the Greenland and Antarctic ice sheets, and will remain elevated for thousands of years (high confidence).
Context
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Sea Level, p. 1217
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: By 2300, GMSL will rise between 0.3 m and 3.1 m under SSP1-2.6, between 1.7 m and 6.8 m under SSP5-8.5 in the absence of marine ice cliff instability, and by up to 16 m under SSP5-8.5 considering marine ice cliff instability (low confidence).

What this does not establish

A projection, with high confidence in AR6; how much it rises afterwards depends strongly on the scenario.

Later work looked for

Crossref, 2021 on, "sea level projection 2100 ice sheet": no IPCC assessment has replaced AR6 (the Seventh Assessment is not yet published); nothing found that changes this.

Claim 25 · checked 24 September 2026 · AI-assisted audit

Claim: This is a place where the usual framing of a target year is misleading.

Kind: This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review: A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

Follows from Box 9.4: the main uncertainty about a high-end rise is when, not whether, so a figure for 2100 understates the commitment.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Box 9.4, p. 1308
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: the main uncertainty related to high-end sea level rise is ‘when’ rather than ‘if’ it arises: the upper limit of 1.01 m of likely sea level range by 2100 for the SSP5-8.5 scenario will be exceeded in any future warming scenario on time scales of centuries to millennia (high confidence)

Claim 26 · checked 24 September 2026 · AI-assisted audit

Claim: The commitment is long even where the rate this century is moderate.

Kind: What a model says. What a theory or model predicts or describes, which is not the same as what has been observed.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, warming levels, p. 1217
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Committed GMSL rise over 2000 years will be about 2 to 6 m with 2°C of peak warming (medium agreement, limited evidence).
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Box 9.4, p. 1308
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: the main uncertainty related to high-end sea level rise is ‘when’ rather than ‘if’ it arises: the upper limit of 1.01 m of likely sea level range by 2100 for the SSP5-8.5 scenario will be exceeded in any future warming scenario on time scales of centuries to millennia (high confidence)

What this does not establish

The 2,000-year commitment is assessed with medium agreement and limited evidence.

Later work looked for

Crossref, 2021 on, "sea level projection 2100 ice sheet": no IPCC assessment has replaced AR6 (the Seventh Assessment is not yet published); nothing found that changes this.

Claim 27 · checked 24 September 2026 · AI-assisted audit

What the range depends on

Claim: What the range depends on

Kind: Framing. Signposting. It asserts nothing a source could check.

The Antarctic tail

Claim: The Antarctic tail

Kind: Framing. Signposting. It asserts nothing a source could check.

Claim: Much of the West Antarctic ice sheet rests on bedrock below sea level, sloping downward inland.

Kind: Observation. Something measured or seen, as the named source reports it.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)FAQ 9.1, p. 1315
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: In places where the ice sheet rests instead on bedrock that is below sea level, and which also deepens inland, including many parts of the Antarctic Ice Sheet, an important process called ‘marine ice sheet instability’ is thought to drive rapid retreat
Supports
Marine ice sheet collapse potentially under way for the Thwaites Glacier Basin, West Antarcticaabstract, first sentence
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Earth and its record · Model
The source reads: Resting atop a deep marine basin, the West Antarctic Ice Sheet has long been considered prone to instability.
Supports
The West Antarctic Ice Sheet may not be vulnerable to marine ice cliff instability during the 21st centuryResults, Response to future ice shelf collapse
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Model
The source reads: Thwaites is located in a deep submarine basin of West Antarctica

What this does not establish

The chapter’s own wording is “many parts of the Antarctic Ice Sheet”; the West Antarctic specifics rest on the Joughin abstract and the Morlighem paper’s description of Thwaites. The bed maps themselves were not read.

Later work looked for

Crossref, 2021 on, "West Antarctic bed topography": nothing that changes it.

Claim 30 · checked 24 September 2026 · AI-assisted audit

Claim: Warm water reaching the grounding line thins the ice, which lets the grounding line retreat into deeper water, which thins it further.

Kind: What a model says. What a theory or model predicts or describes, which is not the same as what has been observed.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.4, p. 1269
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: MISI is a proposed self-reinforcing mechanism within marine ice sheets that lie on a bed that slopes down towards the interior of the ice sheet, whereby, in the absence of ice-shelf buttressing, the position of the grounding line is inherently unstable until reaching an upward sloping bed.
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)FAQ 9.1, p. 1315
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: This happens when the part of the ice sheet that is surrounded by sea water melts. That leads to additional thinning, which in turn accelerates the motion of the glaciers that feed into these areas.
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Ice Sheets, p. 1215
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: These mass losses from the West Antarctic outlet glaciers were mainly induced by ice-shelf basal melt (high confidence)
Qualifies
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.4, p. 1269
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: stable grounding line positions can be reached on downward sloping beds if ice shelves provide buttressing

What this does not establish

AR6 calls this a proposed mechanism. Ice shelves can hold a grounding line stable even on a downward-sloping bed.

Claim 31 · checked 24 September 2026 · AI-assisted audit

Claim: Whether that runs away, and how fast, is not settled.

Kind: Open question. Something the page says is not known.
Review: Presented as open. The page says this is unresolved, and the review found that it is.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.1, p. 1263
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: However, whether unstable WAIS retreat had begun, or was imminent, remained a critical uncertainty. New publications since SROCC have not substantially clarified this question.
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.1, p. 1263
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: In summary, the observed evolution of the ASE glaciers is compatible with, but not unequivocally indicating an ongoing MISI (medium confidence).

Claim 32 · checked 24 September 2026 · AI-assisted audit

Claim: A 2016 model that added the collapse of tall ice cliffs and the fracturing of ice shelves by meltwater produced far larger contributions than earlier work;

Kind: What a model says. What a theory or model predicts or describes, which is not the same as what has been observed.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
Contribution of Antarctica to past and future sea-level riseabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · A simulation · Model
The source reads: including previously underappreciated processes linking atmospheric warming with hydrofracturing of buttressing ice shelves and structural collapse of marine-terminating ice cliffs ... Antarctica has the potential to contribute more than a metre of sea-level rise by 2100 and more than 15 metres by 2500, if emissions continue unabated.
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.4, p. 1269
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: The SROCC noted that the MICI mechanism led one model (DeConto and Pollard, 2016) to lose mass far more rapidly

What this does not establish

DeConto and Pollard were read as an abstract only. AR6 confirms the comparison with other models.

Claim 33 · checked 24 September 2026 · AI-assisted audit

Claim: later studies have questioned whether the cliff mechanism operates as modelled.

Kind: What scholars argue. A report of what specialists argue, or where they disagree.
Review: Source checked. The cited passage was read, and it says this.

Supports
Revisiting Antarctic ice loss due to marine ice-cliff instabilityabstract (accepted manuscript)
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · A simulation · Model
The source reads: MICI is not required to reproduce sea-level changes in the mid-Pliocene, Last Interglacial or 1992-2017 ... We therefore find previous interpretations of the MICI projections over-estimate sea-level rise this century.
Supports
The West Antarctic Ice Sheet may not be vulnerable to marine ice cliff instability during the 21st centuryabstract; Discussion, last paragraph
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · A simulation · Model
The source reads: These experiments show that Thwaites may be less vulnerable to MICI than previously thought, and model projections that include this process should be re-evaluated. ... However, our results do not suggest that the West Antarctic Ice Sheet is stable.
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.4, p. 1270
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: New theoretical evidence suggests that ice-cliff collapse may only occur after very rapid ice shelf disintegration caused by unusually high meltwater production ... Observations from Greenland show that steep cliffs commonly evolve into short floating extensions, rather than collapsing catastrophically

What this does not establish

Neither study rules out cliff failure; both find it unnecessary or much less likely in their models. Morlighem and others stress that West Antarctica is not therefore stable.

Claim 34 · checked 24 September 2026 · AI-assisted audit

Claim: The assessed likely range for 2100 is 0.28 to 0.55 metres under the lowest emissions scenario and 0.63 to 1.01 metres under the highest, measured from the 1995 to 2014 average.

Kind: What a model says. What a theory or model predicts or describes, which is not the same as what has been observed.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Sea Level, p. 1216
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: relative to the period 1995–2014, GMSL will rise ... by 2100 between 0.38 [0.28 to 0.55, likely range] m (SSP1-1.9) and 0.77 [0.63 to 1.01, likely range] m (SSP5-8.5).
Context
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Box 9.4, p. 1308
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: because ‘likely’ implies an assessed likelihood of up to 16% that sea level rise by 2100 will be higher

What this does not establish

A likely range still leaves an assessed chance of up to one in six of a higher rise.

Later work looked for

Crossref, 2021 on, "sea level projection 2100 ice sheet": no IPCC assessment has replaced AR6 (the Seventh Assessment is not yet published); nothing found that changes this.

Claim 35 · checked 24 September 2026 · AI-assisted audit

Claim: Those ranges leave out the ice-sheet processes that cannot be projected with confidence.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Sea Level, p. 1216
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Considering only processes for which projections can be made with at least medium confidence ... These likely range projections do not include those ice-sheet-related processes that are characterized by deep uncertainty.

Later work looked for

Crossref, 2021 on, "sea level projection 2100 ice sheet": no IPCC assessment has replaced AR6 (the Seventh Assessment is not yet published); nothing found that changes this.

Claim 36 · checked 24 September 2026 · AI-assisted audit

Claim: Include them and the 95th percentile under the highest scenario is 2.3 metres by 2100.

Kind: What a model says. What a theory or model predicts or describes, which is not the same as what has been observed.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.6.3.3, p. 1302
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: under SSP5-8.5, low-confidence processes could lead to a total GMSL rise of 0.6–1.6 m over this time period (17th–83rd percentile range of p-box, including SEJ- and MICI-based projections), with 5th–95th percentile projections extending to 0.5–2.3 m (low confidence).

What this does not establish

The 2.3 metres is the top of a 5th to 95th percentile range of 0.5 to 2.3 metres, held with low confidence and built partly from expert judgement and the ice-cliff model.

Later work looked for

Crossref, 2021 on, "sea level projection 2100 ice sheet": no IPCC assessment has replaced AR6 (the Seventh Assessment is not yet published); nothing found that changes this.

Claim 37 · checked 24 September 2026 · AI-assisted audit

Claim: That figure carries low confidence, and a rise approaching two metres cannot be ruled out.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.6.3.3, p. 1302
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: under SSP5-8.5, low-confidence processes could lead to a total GMSL rise of 0.6–1.6 m over this time period (17th–83rd percentile range of p-box, including SEJ- and MICI-based projections), with 5th–95th percentile projections extending to 0.5–2.3 m (low confidence).
Supports
Climate Change 2021: The Physical Science Basis (AR6 Working Group I)Summary for Policymakers, B.5.3
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Global mean sea level rise above the likely range – approaching 2 m by 2100 and 5 m by 2150 under a very high GHG emissions scenario (SSP5-8.5) (low confidence) – cannot be ruled out due to deep uncertainty in ice-sheet processes.

Later work looked for

Crossref, 2021 on, "sea level projection 2100 ice sheet": no IPCC assessment has replaced AR6 (the Seventh Assessment is not yet published); nothing found that changes this.

Corrected

24 September 2026. Previously: “Include them and the highest scenario reaches 2.3 metres by 2100 at the 95th percentile, which cannot be excluded.” AR6 holds the 2.3 metres with low confidence, and its statement that a higher rise cannot be ruled out is about a rise approaching 2 metres, in the Summary for Policymakers.

Claim 38 · checked 24 September 2026 · AI-assisted audit

Claim: Where the uncertainty is

Kind: Framing. Signposting. It asserts nothing a source could check.

Claim: Thermal expansion and glacier melt, both measured, both driven by well-understood processes.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Box 9.1, p. 1220
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Reference work
The source reads: There is high confidence in the understanding of processes causing thermosteric sea level change ... There is medium to high confidence in the understanding of processes leading to sea level contributions from glaciers
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Cross-Chapter Box 9.1, p. 1285
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Measurement
The source reads: The assessed sum of the observed components indicates that GMSL very likely increased by 72 mm to 117 mm over the period 1971–2018 ... has a very likely range of 73–146 mm and, as a result, the sea level budget is closed for this period

Later work looked for

Crossref, 2021 on, "sea level projection 2100 ice sheet": no IPCC assessment has replaced AR6 (the Seventh Assessment is not yet published); nothing found that changes this.

Corrected

24 September 2026. Previously: “Thermal expansion and glacier melt, measured and modelled consistently.” The chapter gives high and medium-to-high confidence in the processes; no statement that models and measurements agree for these two terms specifically was found.

Claim 40 · checked 24 September 2026 · AI-assisted audit

Claim: Projectable with real confidence.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Table 9.9, caption, p. 1302
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Unshaded cells represent processes in whose projections there is medium confidence.

What this does not establish

Medium confidence, in the IPCC’s terms.

Later work looked for

Crossref, 2021 on, "sea level projection 2100 ice sheet": no IPCC assessment has replaced AR6 (the Seventh Assessment is not yet published); nothing found that changes this.

Claim 41 · checked 24 September 2026 · AI-assisted audit

Claim: Most of this century’s rise, under moderate scenarios.

Kind: What a model says. What a theory or model predicts or describes, which is not the same as what has been observed.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Table 9.9, p. 1302
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Thermal expansion 0.12 (0.09–0.15) 0.14 (0.11–0.18) 0.20 (0.16–0.24) ... Glaciers 0.08 (0.06–0.10) 0.09 (0.07–0.11) 0.12 (0.10–0.15) ... Total (2100) 0.38 (0.28–0.55) 0.44 (0.32–0.62) 0.56 (0.44–0.76)
SSP1-1.9, SSP1-2.6 and SSP2-4.5, in metres: thermal expansion and glaciers are just over half the median total in each.

What this does not establish

“Most” is just over half of the median total under the three lower scenarios.

Later work looked for

Crossref, 2021 on, "sea level projection 2100 ice sheet": no IPCC assessment has replaced AR6 (the Seventh Assessment is not yet published); nothing found that changes this.

Claim 42 · checked 24 September 2026 · AI-assisted audit

Claim: Greenland losing mass at a measured and accelerating rate.

Kind: Observation. Something measured or seen, as the named source reports it.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Ice Sheets, p. 1215
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Measurement
The source reads: The mass-loss rate was on average 39 [–3 to +80] Gt yr –1 over the period 1992–1999, 175 [131 to 220] Gt yr –1 over the period 2000–2009 and 243 [197 to 290] Gt yr –1 over the period 2010–2019.
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)FAQ 9.2, p. 1318
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Melting of the two large ice sheets in Greenland and Antarctica has contributed about 13% and 7%, respectively, during 1971 to 2018, but melting has accelerated in the recent decades, increasing their contribution to 22% and 14% since 2016.

Later work looked for

Crossref, 2022 on, "mass balance Greenland Antarctic ice sheets 1992 to 2020": the IMBIE 2023 assessment (Otosaka and others, abstract) reports ice-sheet losses accelerating since the 1990s; consistent.

Claim 43 · checked 24 September 2026 · AI-assisted audit

Claim: A large contribution, with the physics of surface melting reasonably understood.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Ice Sheets, p. 1215
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: The loss of ice from Greenland will become increasingly dominated by surface melt, as marine margins retreat and the ocean-forced dynamic response of ice-sheet margins diminishes (high confidence).
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Box 9.1, p. 1220
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Reference work
The source reads: There is medium confidence in ice-sheet processes but low confidence in their forcing (ocean changes and ice-shelf collapse) and in instability processes
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Table 9.9, p. 1302
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Greenland 0.05 (0.00–0.09) 0.06 (0.01–0.10) 0.08 (0.04–0.13) 0.11 (0.07–0.16) 0.13 (0.09–0.18) 0.18 (0.09–0.59) Antarctica 0.10 (0.03–0.25) 0.11 (0.03–0.27) 0.11 (0.03–0.29) 0.11 (0.03–0.31) 0.12 (0.03–0.34) 0.19 (0.02–0.56)
Medians and likely ranges in metres for 2100 under SSP1-1.9 to SSP5-8.5; the last column is the low-confidence 17th to 83rd percentile range.

What this does not establish

AR6 also includes faster-than-projected change in Greenland in its high-end storyline.

Later work looked for

Claim 44 · checked 24 September 2026 · AI-assisted audit

Claim: Marine-based Antarctic ice, whose unstable retreat has never been unambiguously observed.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.1, p. 1263
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: In summary, the observed evolution of the ASE glaciers is compatible with, but not unequivocally indicating an ongoing MISI (medium confidence).
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.1, p. 1263
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: However, whether unstable WAIS retreat had begun, or was imminent, remained a critical uncertainty. New publications since SROCC have not substantially clarified this question.
Supports
Revisiting Antarctic ice loss due to marine ice-cliff instabilityabstract (accepted manuscript)
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Model
The source reads: But the MICI mechanism has not been observed in the modern era
Qualifies
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.4, p. 1270
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: only Crane Glacier on the Peninsula has shown retreat consistent with MICI

Later work looked for

Crossref, 2022 on, "West Antarctic ice sheet tipping point already crossed" and "Thwaites Glacier collapse committed": nothing found that settles whether unstable retreat has begun.

Corrected

24 September 2026. Previously: “Marine-based Antarctic ice with no analogue in the instrumental record.” AR6 finds the Amundsen Sea glaciers compatible with the onset of marine ice sheet instability and records retreat consistent with cliff failure at one Peninsula glacier, so “no analogue” overstated it. What the record lacks is unambiguous observation.

Claim 45 · checked 24 September 2026 · AI-assisted audit

Claim: The widest part of the range, and the part that grows most after 2100.

Kind: What a model says. What a theory or model predicts or describes, which is not the same as what has been observed.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Table 9.9, p. 1302
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Greenland 0.05 (0.00–0.09) 0.06 (0.01–0.10) 0.08 (0.04–0.13) 0.11 (0.07–0.16) 0.13 (0.09–0.18) 0.18 (0.09–0.59) Antarctica 0.10 (0.03–0.25) 0.11 (0.03–0.27) 0.11 (0.03–0.29) 0.11 (0.03–0.31) 0.12 (0.03–0.34) 0.19 (0.02–0.56)
Medians and likely ranges in metres for 2100 under SSP1-1.9 to SSP5-8.5; the last column is the low-confidence 17th to 83rd percentile range.
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.6, p. 1272
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: projections in which Antarctica contributes much more than the assessed ranges under sustained very high greenhouse gas emissions – that is, around 7–14 m to GMSL by 2300 (DeConto et al., 2021), cannot be ruled out
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.6, p. 1272
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Deep uncertainty remains in the role of AIS instabilities under very high emissions.

What this does not establish

In the low-confidence projections for 2100 under the highest scenario, Greenland’s range is as wide as Antarctica’s.

Later work looked for

Crossref, 2021 on, "marine ice cliff instability West Antarctica twenty-first century": Morlighem and others (2024) find Thwaites less vulnerable to MICI than earlier modelling; added as a source.

Corrected

24 September 2026. Previously: “The whole upper tail.” AR6 places part of the upper tail in Greenland. Antarctica has the widest range and dominates beyond 2100.

Claim 46 · checked 24 September 2026 · AI-assisted audit

Claim: A process that either engages or does not, with very different outcomes.

Kind: What a model says. What a theory or model predicts or describes, which is not the same as what has been observed.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.4, p. 1269
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: The sea level rise contribution of the AIS therefore crucially depends on the behaviour of individual ice shelves and outlet glacier systems and whether they enter MISI for a given level of warming
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.6, p. 1272
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: The West and East Antarctic ice sheets are considered to be tipping elements – that is, susceptible to critical thresholds.
Context
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.6, p. 1273
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: confirm the SR1.5 assessment that a threshold for WAIS instability may be close to 1.5°C–2°C (medium confidence)

What this does not establish

AR6 locates the West Antarctic threshold only approximately, close to 1.5 to 2 °C with medium confidence, and whether a given glacier has crossed it is not known.

Claim 47 · checked 24 September 2026 · AI-assisted audit

Why a global number is the wrong question locally

Claim: Why a global number is the wrong question locally

Kind: This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review: A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

The heading of a passage that follows from claims 49 and 50.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)FAQ 9.2, p. 1318
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: In many places, local sea level change will be larger or smaller than the global average.

Claim 48 · checked 24 September 2026 · AI-assisted audit

Claim: Land rises and sinks, ocean currents pile water up in some places, and the gravitational pull of an ice sheet holds water near it, so losing ice in Greenland lowers the sea locally and raises it more than average far away.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Sea Level, p. 1216
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Regional differences in sea level arise from: ocean dynamics; changes in Earth gravity, rotation and deformation due to land ice and land-water changes; and vertical land motion.
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Box 9.1, p. 1221
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Reference work
The source reads: Contemporary terrestrial mass loss leads to elastic solid Earth uplift and a nearby RSL fall ... Farther away (around more than 7000 km for a single source of terrestrial mass loss), RSL rises more than the global average, due to first-order gravitational effects.
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)FAQ 9.2, p. 1318
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Melt from a polar ice sheet therefore raises sea level most in the opposite hemisphere or in low latitudes – amounting to tens of centimetres difference in rise between regions by 2100.

Later work looked for

Crossref, 2022 on, "regional sea level rise projections gravitational fingerprints ice sheet": nothing that changes the pattern AR6 describes.

Claim 49 · checked 24 September 2026 · AI-assisted audit

Claim: The consequence is that some coasts will see substantially more than the global mean and some less,

Kind: What a model says. What a theory or model predicts or describes, which is not the same as what has been observed.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)FAQ 9.2, p. 1318
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: In many places, local sea level change will be larger or smaller than the global average.
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)FAQ 9.2, p. 1318
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Melt from a polar ice sheet therefore raises sea level most in the opposite hemisphere or in low latitudes – amounting to tens of centimetres difference in rise between regions by 2100.
Qualifies
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Sea Level, p. 1216
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Over the 21st century, the majority of coastal locations will experience a median projected regional sea level rise within ±20% of the median projected GMSL change (medium confidence).
Context
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)FAQ 9.2, p. 1318
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: In many regions within low-lying delta regions (such as New Orleans and the Ganges–Brahmaputra delta), the land is rapidly subsiding

What this does not establish

AR6 expects most coasts to see a median rise within 20 per cent of the global median; the larger departures are regional, as where land is subsiding.

Later work looked for

Crossref, 2022 on, "regional sea level rise projections gravitational fingerprints ice sheet": nothing that changes the pattern AR6 describes.

Claim 50 · checked 24 September 2026 · AI-assisted audit

Claim: and planning from the global number is an error in both directions.

Kind: This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review: A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

The page’s conclusion from claims 49 and 50.

Claim 51 · checked 24 September 2026 · AI-assisted audit

The part the record is too short for

Claim: The part the record is too short for

Kind: This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review: A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

The section title, which summarises claim 57.

Claim 52 · checked 24 September 2026 · AI-assisted audit

Claim: Losing ice in Greenland lowers the sea in Greenland and raises it in the tropics.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Box 9.1, p. 1221
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Reference work
The source reads: Contemporary terrestrial mass loss leads to elastic solid Earth uplift and a nearby RSL fall ... Farther away (around more than 7000 km for a single source of terrestrial mass loss), RSL rises more than the global average, due to first-order gravitational effects.
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)FAQ 9.2, p. 1318
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: Melt from a polar ice sheet therefore raises sea level most in the opposite hemisphere or in low latitudes – amounting to tens of centimetres difference in rise between regions by 2100.

Later work looked for

Crossref, 2022 on, "regional sea level rise projections gravitational fingerprints ice sheet": nothing that changes the pattern AR6 describes.

Claim 53 · checked 24 September 2026 · AI-assisted audit

Claim: Gravity is local.

Kind: This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review: A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

A compression of claim 53: the pull that matters here is felt most near the ice sheet.

Claim 54 · checked 24 September 2026 · AI-assisted audit

Whether a threshold has already been crossed

Claim: Whether a threshold has already been crossed

Kind: Open question. Something the page says is not known.
Review: Presented as open. The page says this is unresolved, and the review found that it is.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.1, p. 1263
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: However, whether unstable WAIS retreat had begun, or was imminent, remained a critical uncertainty. New publications since SROCC have not substantially clarified this question.

Claim 55 · checked 24 September 2026 · AI-assisted audit

Claim: Parts of West Antarctica may already be committed to eventual collapse under warming that has already happened.

Kind: Open question. Something the page says is not known.
Review: Presented as open. The page says this is unresolved, and the review found that it is.

Supports
Marine ice sheet collapse potentially under way for the Thwaites Glacier Basin, West Antarcticaabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · A simulation · Model
The source reads: Except possibly for the lowest-melt scenario, the simulations indicate that early-stage collapse has begun. Less certain is the time scale, with the onset of rapid (>1 mm per year of sea-level rise) collapse in the different simulations within the range of 200 to 900 years.
Supports
Unavoidable future increase in West Antarctic ice-shelf melting over the twenty-first centuryImplications, last paragraph
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · A simulation · Model
The source reads: The opportunity to preserve the WAIS in its present-day state has probably passed, and policymakers should be prepared for several metres of sea-level rise over the coming centuries.
Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.1, p. 1263
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: In summary, the observed evolution of the ASE glaciers is compatible with, but not unequivocally indicating an ongoing MISI (medium confidence).
Qualifies
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.1, p. 1263
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: suggests that MISI is not required to explain the observed current mass loss rates of the WAIS, because they are consistent with external climate drivers
Qualifies
Unavoidable future increase in West Antarctic ice-shelf melting over the twenty-first centuryImplications, limitations paragraph
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · A simulation · Model
The source reads: Our study uses a single ice–ocean model forced by a single climate model and does not consider feedbacks related to ice-shelf geometry

Claim: The observational record is too short and the process too slow to tell from measurements.

Kind: What scholars argue. A report of what specialists argue, or where they disagree.
Review: Source checked. The cited passage was read, and it says this.

Supports
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.4.2.1, p. 1263
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: However, whether unstable WAIS retreat had begun, or was imminent, remained a critical uncertainty. New publications since SROCC have not substantially clarified this question.
Supports
Unavoidable future increase in West Antarctic ice-shelf melting over the twenty-first centuryMain, third paragraph
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Observational study: associations, not causes
The source reads: Observations cannot be used to detect such a long-term ocean warming trend in this region, as data collection only began in 1994
Context
Marine ice sheet collapse potentially under way for the Thwaites Glacier Basin, West Antarcticaabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · A simulation · Model
The source reads: with the onset of rapid (>1 mm per year of sea-level rise) collapse in the different simulations within the range of 200 to 900 years

What this does not establish

The time scale of 200 to 900 years comes from one modelling study, read as an abstract.

Claim 57 · checked 24 September 2026 · AI-assisted audit

Claim: A commitment that takes centuries to express itself is invisible to a satellite record that began in 1992,

Kind: This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review: A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

The satellite records of Antarctic mass and of sea level both start in 1992 in AR6; the centuries come from the modelled onset time in claim 57.

Context
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Section 9.2.4.1, p. 1234
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: continuous satellite altimetry record, beginning in 1992
Context
Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Executive Summary, Ice Sheets, p. 1215
Cited · Link answered, 19 October 2026 · The cited passage was read, 24 September 2026 · Earth and its record · Consensus statement
The source reads: The Antarctic Ice Sheet has lost 2670 [1800 to 3540] Gt mass over the period 1992–2020
Context
Marine ice sheet collapse potentially under way for the Thwaites Glacier Basin, West Antarcticaabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · A simulation · Model
The source reads: within the range of 200 to 900 years

Claim 58 · checked 24 September 2026 · AI-assisted audit

Claim: which is a limit on the question and not a reassurance.

Kind: This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review: A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

The page’s reading of claim 57: absence of a signal in a short record is not evidence of stability.

Claim 59 · checked 24 September 2026 · AI-assisted audit

What was read

Ocean, Cryosphere and Sea Level Change (AR6 Working Group I, Chapter 9)Intergovernmental Panel on Climate Change · IPCC_AR6_WGI_Chapter09.pdf (Fox-Kemper and others, 2021); Executive Summary, Box 9.1, Sections 9.4.2.1, 9.4.2.4 to 9.4.2.6, 9.6.1, 9.6.3.3, 9.7, Cross-Chapter Box 9.1, Box 9.4, Table 9.9 and FAQs 9.1 and 9.2 readThe cited passage was read, 24 September 2026 · IPCC; quoted briefly
Contribution of Antarctica to past and future sea-level riseDeConto and Pollard, Nature · Europe PMC record, PMID 27029274Abstract only, 24 September 2026 · Copyright; quoted brieflyPaywalled, no open copy found through unpaywall.
Revisiting Antarctic ice loss due to marine ice-cliff instabilityEdwards and others, Nature · Authors' accepted manuscript (King's Research Portal copy deposited in HAL, hal-02374873); abstract and results read. Wording differs slightly from the published abstractRead in full, 24 September 2026 · CC BY 4.0 (HAL deposit)
The West Antarctic Ice Sheet may not be vulnerable to marine ice cliff instability during the 21st centuryMorlighem and others, Science Advances · Europe PMC full text, PMC11338217Read in full, 24 September 2026 · CC BY 4.0
Climate Change 2021: The Physical Science Basis (AR6 Working Group I)Intergovernmental Panel on Climate Change · AR6 WG I Summary for Policymakers (IPCC_AR6_WGI_SPM.pdf), B.5.3 and B.5.4 readThe cited passage was read, 24 September 2026 · IPCC; quoted briefly
Marine ice sheet collapse potentially under way for the Thwaites Glacier Basin, West AntarcticaJoughin, Smith and Medley, Science · Europe PMC record, PMID 24821948Abstract only, 24 September 2026 · Copyright; quoted brieflyPaywalled, no open copy found through unpaywall or Europe PMC.
Unavoidable future increase in West Antarctic ice-shelf melting over the twenty-first centuryNaughten, Holland and De Rydt, Nature Climate Change · Europe PMC full text, PMC13538064Read in full, 24 September 2026 · CC BY 4.0