The seas we’ve already locked in
Satellite altimetry shows the rate of sea level rise has increased by 40% within the observational record — from 2.77 mm/yr in 1993–2005 to 3.88 mm/yr today. Direct measurement by two independent constellations, not a model output.
Data as of February 2026
Global mean sea level
Current rate
3.88 mm/yr
vs 2.77 mm/yr
1993–2005 baseline
1993–2005 baseline
Cumulative rise since 1993
112.0 mm
Rate acceleration
1.4× faster
Measurement
Satellite altimetry
TOPEX · Jason-1/2/3 · Sentinel-6
ⓘ methodology & sources
Data: CU Sea Level Research Group (sealevel.colorado.edu), seasonal signals removed. Satellites: TOPEX/Poseidon (1992–2005), Jason-1 (2001–2013), Jason-2 (2008–2019), Jason-3 (2016–present), Sentinel-6 (2020–present). Rate periods: 1993–2005 vs 2005–present. Two independent satellite constellations with overlapping missions confirm the trend. Citation: Nerem et al. 2018 (Sci. Adv.) for rate-acceleration methodology; CU 2026 release for current values.
Thermal expansion · sea level
Full column rate
1.20 mm/yr
0–2000 m · 2005–present
Deep layer addition
+0.42 mm/yr
700–2000 m · previously invisible
Share of total SLR
31%
of observed rise rate
Thermosteric committed floor
+28 mm
locked in from heat to date
Ocean heat penetration · 0–2000 m
0 m
300 m
700 m
2000 m
Heat below 700 m cannot escape on any human timescale.
What Argo revealed · 2005–present · same coefficient throughout
+0.42
mm/yr
from the deep ocean
Argo revealed 35% more expansion than upper-ocean instruments could see
Thermosteric committed floor · physics floor
+28 mm
From heat already absorbed · independent of future emissions · irreversible on civilizational timescales
Causal pipeline · EEI → expansion → sea level
EEI · 12-mo mean
+2.00 W/m²
→
Ocean heat 0–2000 m
250 ZJ
→
Thermosteric rise
+27.5 mm
→
Share of SLR
31%
ⓘ methodology & sources
Thermosteric sea level contribution derived from 0-2000m ocean heat content (NCEI/Argo, same sidecar as Oceans panel). Conversion: ~0.11 mm per ZJ of OHC change (IPCC AR6 approximation). Covers Argo float network depth range 0-2000m; deep-ocean expansion below 2000m is not captured and adds to the true thermosteric total. IPCC AR6 estimates thermosteric at 40-44% of total sea level rise; the ~30% shown here reflects the 0-2000m layer only.
Antarctic ice sheet
SL Contribution
+0.012 mm/yr
2025 (latest full year)
Cumulative since 2002
+7.399 mm
sea level equivalent
2002–2010 mean
+0.274 mm/yr
2011–present mean
+0.317 mm/yr
Peak rate
+0.904 mm/yr (2015)
ⓘ methodology & sources
NASA GRACE/GRACE-FO JPL Mascon RL06.3Mv04 (Tellus Level-4 regional mass anomaly time series); podaac.jpl.nasa.gov; C3206284786-POCLOUD. Coverage: 2002-present, monthly, ~3-month processing lag. Mass anomaly in Gt (relative to 2002–2021 mean) converted to mm sea level equivalent (1 mm SLE = 361.8 Gt); cumulative anchored to 2002. Updated monthly via collect_ice_sheets.py.
Greenland ice sheet
SL Contribution
+0.318 mm/yr
2025 (latest full year)
Cumulative since 2002
+15.967 mm
sea level equivalent
2002–2010 mean
+0.659 mm/yr
2011–present mean
+0.632 mm/yr
Peak rate
+1.286 mm/yr (2011)
ⓘ methodology & sources
NASA GRACE/GRACE-FO JPL Mascon RL06.3Mv04 (Tellus Level-4 regional mass anomaly time series); podaac.jpl.nasa.gov; C3206299308-POCLOUD. Coverage: 2002-present, monthly, ~3-month processing lag. Mass anomaly in Gt (relative to 2002–2021 mean) converted to mm sea level equivalent (1 mm SLE = 361.8 Gt); cumulative anchored to 2002. Updated monthly via collect_ice_sheets.py.
BY 2100
LOCKED IN
Committed floor
0.2–0.3 m
by 2100, any scenario
Low emissions
0.3–0.6 m
SSP1-2.6 · 2100
High emissions
0.6–1.0 m
SSP5-8.5 · 2100
Thermal expansion from heat already absorbed is irreversible on human timescales.
The floor is locked in regardless of future emissions decisions.
Greenland and Antarctic destabilization could raise this floor significantly.
ⓘ methodology & sources
IPCC AR6 WGI Chapter 9 and SPM Table SPM.2. Committed thermal expansion alone: ~0.1-0.2 m regardless of future emissions (Church et al. 2013; IPCC AR6). Scenario ranges shown as likely ranges (66th percentile) for 2100. Current sea level ~0.11 m above 1993 satellite altimetry baseline (CU Sea Level Research Group 2026).
Glacier mass balance
Loss rate · 2025
–1091 mm w.e./yr
IPCC AR6: ~1.0 mm/yr sea level (1993-2018)
Rate acceleration
+70%
faster than 1992–2010 avg
1992–2010 avg
–519 mm w.e./yr
2011–present avg
–880 mm w.e./yr
ⓘ methodology & sources
WGMS reference glacier synthesis (~90 long-record glaciers worldwide). Annual specific mass balance in mm w.e. (water equivalent). Not directly mm sea level — IPCC AR6 (Table 2.5) estimates global glacier sea level contribution at 0.92 ± 0.16 mm/yr for 1993-2018, rising to ~1.1 mm/yr in 2010-2019. Data updated annually each spring with prior season measurements. WGMS (2024): Fluctuations of Glaciers Database. DOI:10.5904/wgms-fog-2024-11.