The effective rate of change in glacier thickness, also known as the glaciological mass balance, is a measure of the average change in a glacier's thickness after correcting for changes in density associated with the compaction of snow and conversion to ice. The map shows the average annual rate of thinning since 1970 for the 173 glaciers that have been measured at least 5 times between 1970 and 2004 (Dyurgerov and Meier 2005). Larger changes are plotted as larger circles and towards the back.

All survey regions except Scandinavia show a net thinning. This widespread glacier retreat is generally regarded as a sign of global warming.

During this period, 83% of surveyed glaciers showed thinning with an average loss across all glaciers of 0.31 m/yr. The most rapidly growing glacier in the sample is Engabreen glacier in Norway with a thickening of 0.64 m/yr. The most rapidly shrinking was Ivory glacier in New Zealand which was thinning at 2.4 m/yr. Ivory glacier had totally disintegrated by circa 1988 [1].

This figure was originally prepared by Rober A. Rohde from published data and is incorporated into the Global Warming Art project.

Image from Global Warming Art

This image is an original work created for Global Warming Art. Please refer to the image description page for more information.

已授權您依據自由軟體基金會發行的無固定段落、封面文字和封底文字GNU自由文件授權條款1.2版或任意後續版本，對本檔進行複製、傳播和／或修改。該協議的副本列在GNU自由文件授權條款中。http://www.gnu.org/copyleft/fdl.htmlGFDLGNU Free Documentation Licensetruetrue

	此檔案採用共享創意 姓名標示-相同方式分享 3.0 未在地化版本授權條款。
	您可以自由： 分享 – 複製、發佈和傳播本作品 重新修改 – 創作演繹作品 惟需遵照下列條件： 姓名標示 – 您必須指名出正確的製作者，和提供授權條款的連結，以及表示是否有對內容上做出變更。您可以用任何合理的方式來行動，但不得以任何方式表明授權條款是對您許可或是由您所使用。 相同方式分享 – 如果您利用本素材進行再混合、轉換或創作，您必須基於如同原先的相同或兼容的條款，來分布您的貢獻成品。
	已新增授權條款標題至此檔案，作為GFDL授權更新的一部份。http://creativecommons.org/licenses/by-sa/3.0/CC BY-SA 3.0Creative Commons Attribution-Share Alike 3.0truetrue

This sample of mountain glaciers excludes the primary ice sheets of Greenland and Antarctica.

It should be acknowledged that glacier sampling is heavily biased towards North America and Europe. Africa has only a handful of glaciers, whereas continental Australia has none. However substantial unsampled mountain glaciers do exist in South America, Asia and the margins of Antarctica. Despite their importance, none of the marginal Antarctic glaciers have had their mass balance sampled at least 5 times since 1970.

These estimates of ice sheet thinning do not include glacier mass lost due to iceberg calving. Such calving is not significant for most mountain glaciers, since only a small proportion of these glaciers terminate in the ocean.

• Dyurgerov, Mark B. and Mark F. Meier (2005). "Glaciers and the Changing Earth System: A 2004 Snapshot". Institute of Arctic and Alpine Research, Occasional Paper 58.

• 
  Portuguese