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 Global Glacier Volume Change (1960–1998)

The line with closed circles shows that glaciers worldwide have shrunk over the last 30 years.

The line with open circles represents worldwide changes in glacier volume from year to year. To interpret this line, consult the scale on the left side of the graph, which shows the annual change in glacier volume in cubic kilometers. Only four years have points above the 0 line—meaning that glaciers gained in volume only four years out of 28.

Glaciers and ice sheets currently cover 10% of the land area on earth and contain about 75% of its freshwater. Because of their greater size and thickness, glaciers respond more slowly than snow and sea ice to short-term changes in weather and climate. Scientists can therefore keep track of fluctuations in glacial volume worldwide as one indicator of long-term climate trends.

The data on this graph comes primarily from aerial and satellite photography. Some scientists have also studied eighteenth century paintings of the Swiss Alps and compared them with present-day photographs to track how glaciers have responded to climate change over the last two centuries.

The data on this graph come from field measurements on glaciers around the world, which are used to estimate the change in the unmeasured glaciers. Aerial and satellite photography also support the field evidence of glacier shrinkage.

 glossary glossary terms  

Click for definitions of words used on this page:

remote sensing
statistical significance

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Global Glacier Mass Balance

Global Glacier Volume Change (1960–1998) - The line with closed circles represents the total change in glacial mass worldwide over a 28-year time period. To interpret this line, consult the scale on the right side of the graph, which shows change in cubic kilometers. Glaciers worldwide have been shrinking. Source:Institute of Arctic and Alpine Research, University of Colorado, Boulder

 questions about the data

question How are galciers in Antarctica changing? Glaciologist Andrew Fountain talks about his research on the glaciers in Antarctic's dry valleys.

email Email your own questions about this data set. 

 research connection  

Measuring changes in the volume of a glacier using ground-based techniques is accurate, but very slow and expensive. Scientists are investigating more sophisticated techniques, such as airborne laser mapping of the glacier surface to track fluctuations in glacial volume over time. However, these techniques are costly, making it impractical to track even a fraction of the 67,000 glaciers currently cataloged by the National Snow and Ice Data Center. However, a combination of field measurements, remote sensing (satellite and airborne) and statistical techniques are being applied to assess glacier changes.

 related sites  

All About Glaciers - Created by the National Snow and Ice Data Center, this site offers glacier facts, news stories about recent glacier happenings, links to glacier research, projects and glaciological organizations online, and a quick tour through the life of a glacier.

Glacier- A website about Antarctica and the part Antarctica plays in our global system of weather and climate and oceans and geology.

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