Yearly Global Mean Sea Level Rise

Sea level rise refers to the long-term increase in the average level of the world’s oceans, typically measured relative to a historical baseline such as the year 1901. This rise is tracked using the scientific indicator Global Mean Sea Level (GMSL), which measures changes in the average elevation of the ocean surface globally.

The rise in sea levels is primarily driven by two factors: thermal expansion, where seawater expands as it warms due to climate change, and the addition of water from land-based ice sheets, glaciers, and other sources.

Sea level rise poses significant risks for coastal ecosystems and the 680 million people living in low-lying islands and coastal regions. It makes coastal areas more vulnerable to storm surges, tides, and waves, which can lead to flooding and erosion.

Rate of Sea Level Rise

Sea levels are rising much faster in recent decades than before. In the last decade, the sea level has risen 4.3 cm. This is more than double compared to the average rate since 1901.

Key Take-Aways

• Rise Since 1901: Sea levels have risen by approximately 228 mm (22.8 cm) since the start of the 20th century.
• Accelerated Sea Level Rise: From 2019 to 2024, global mean sea level rose by 26 mm (~4.3 mm per year). This is more than double the long-term average rate of 1.8 mm/year since 1901.
• The Main Drivers of Sea Level Rise are thermal expansion (warming oceans) and melting land-based ice (ice sheets & glaciers).
• Ongoing Acceleration: The rate of rise is still accelerating due to continued ice sheet melt and deep ocean warming, consistent with climate model projections.
• Increased Risks to Coastal Areas: Rising sea levels amplify storm surges, coastal erosion, and flooding, especially in low-lying coastal regions.
• Vulnerable Populations: About 680 million people (≈10% of the global population) live in low-lying islands and coastal areas, putting them at heightened risk.

About the Data

The data presented is derived from both tide gauge reconstructions and satellite altimetry observations. The satellite data is particularly critical, providing more recent and comprehensive measurements from 1993 onward. The data also incorporates uncertainty estimates.

The data is produced by the Indicators of Global Climate Change (IGCC) initiative to spread indicators of climate change that are consistent with the IPCC Assessment Report 6. The IGCC produces estimates for key climate indicators: emissions of greenhouse gases and short-lived climate forcers, greenhouse gas concentrations, radiative forcing, surface temperature changes, the Earth’s energy imbalance, warming attributed to human activities, the remaining carbon budget, sea level rise, and estimates of global temperature extremes.

Units and Measures

Sea level rise is expressed in centimeters (cm) and millimeters (mm).

Data Sources

IGCC Indicators of Global Climate Change 2024: annual update of key indicators of the state of the climate system and human influence, Piers M. Forster et al.
Credits: Smith, C., Walsh, T., Gillett, N., Hauser, M., Krummel, P., Lamb, W., Lamboll, R., Mühle, J., Palmer, M., Ribes, A., Schumacher, D., Seneviratne, S., Trewin, B., von Schuckmann, K., & Forster, P. (2025). Indicators of Global Climate Change 2024 (v2025.05.02). Zenodo.Update cycle: yearlyDelay: mixed