Global Mean Sea Level Rise Data Story

This data contains cumulative changes in sea level for the world’s oceans since 1880, based on a combination of long-term tide gauge measurements and recent satellite measurements.

About This Data

Global Average Absolute Sea Level Change, 1880-2014 from the US Environmental Protection Agency using data from CSIRO, 2015; NOAA, 2015.

This data contains cumulative changes in sea level for the world's oceans since 1880, based on a combination of long-term tide gauge measurements and recent satellite measurements.

It shows average absolute sea level change, which refers to the height of the ocean surface, regardless of whether nearby land is rising or falling.

Satellite data are based solely on measured sea level, while the long-term tide gauge data include a small correction factor because the size and shape of the oceans are changing slowly over time. (On average, the ocean floor has been gradually sinking since the last Ice Age peak, 20,000 years ago.)

Data Sources

Sea Level Change Over Time

This line chart displays sea level measurements from all three datasets over time. EPA data (1880-2013) is shown in purple with uncertainty bands. CSIRO data (1880-2019) is shown in green. Satellite data (1993-2020) is shown in red. All data is displayed in millimeters (EPA converted from inches).

❄️ Sea Level Rise & Glacier Mass Balance Correlation

This multi-axis visualization shows the relationship between global sea level rise and glacier mass loss from 1956 to 2019. As glaciers lose mass (shown as increasingly negative values on the right axis), sea level rises (left axis). The inverse correlation reveals how glacier melt contributes significantly to sea level rise.

🌡️ Sea Level Rise & Global Temperature Correlation

This multi-axis visualization shows the relationship between global sea level rise and global temperature anomalies from 1880 to 2019. Temperature anomalies (right axis) represent deviations from the 1951-1980 baseline. Both trends rise together, demonstrating how thermal expansion of ocean water and accelerated ice melt from warming contribute to sea level rise (left axis).

🌊 Horizon View - Compact Multi-Dataset Comparison

This horizon chart shows all three datasets in a compact, layered format. Each row represents one dataset (EPA, CSIRO, Satellite), with blue bands indicating the magnitude of sea level rise. Darker/higher bands represent higher sea level values. All data is displayed in millimeters (EPA converted from inches).

📅 Calendar Heatmap - Annual Rate of Change Patterns

This heatmap shows the annual rate of sea level change using CSIRO Reconstructed GMSL data. Each cell represents one year, organized by decades. The color indicates how much sea level rose or fell each year (blue = slower rise, red = faster rise) calculated by comparing consecutive year values. Values are in millimeters of sea level rise per year.

Decade Comparison

This bar chart shows the average sea level for each decade. Data uses EPA for decades 1880-2009 and CSIRO for 2010-2019. The average is calculated by summing all year values within each decade and dividing by 10. All values are in millimeters.

Key Findings

We estimate the rise in global average sea level from satellite altimeter data for 1993–2009 and from coastal and island sea-level measurements from 1880 to 2009.

For 1993–2009 and after correcting for glacial isostatic adjustment, the estimated rate of rise is 3.2 ± 0.4 mm year⁻¹ from the satellite data and 2.8 ± 0.8 mm year⁻¹ from the in situ data.

The global average sea-level rise from 1880 to 2009 is about 210 mm. The linear trend from 1900 to 2009 is 1.7 ± 0.2 mm year⁻¹ and since 1961 is 1.9 ± 0.4 mm year⁻¹.

There is considerable variability in the rate of rise during the twentieth century but there has been a statistically significant acceleration since 1880 and 1900 of 0.009 ± 0.003 mm year⁻² and 0.009 ± 0.004 mm year⁻², respectively.

Since the start of the altimeter record in 1993, global average sea level rose at a rate near the upper end of the sea level projections of the Intergovernmental Panel on Climate Change's Third and Fourth Assessment Reports. However, the reconstruction indicates there was little net change in sea level from 1990 to 1993, most likely as a result of the volcanic eruption of Mount Pinatubo in 1991.

References

Note: This shows global mean sea level. Local changes vary due to land subsidence, ocean currents, and regional climate patterns.