This figure shows the average rate of thickness change in mountain glaciers around the world. This information, known as the glaciological mass balance, is found by measuring the annual snow accumulation and subtracting surface ablation driven by melting, sublimation, or wind erosion. These measurements do not account for thinning associated with iceberg calving, flow related thinning, or subglacial erosion. All values are corrected for variations in snow and firn density and expressed in meters of water equivalent (Dyurgerov 2002).

Measurements are shown as both the annual average thickness change and the accumulated change during the fifty years of measurements presented. Years with a net increase in glacier thickness are plotted upwards and in red; years with a net decrease in glacier thickness (i.e. positive thinning) are plotted downward and in blue. Only three years in the last 50 have experienced thickening in the average.

Systematic measurements of glacier thinning began in the 1940s, but fewer than 15 sites had been measured each year until the late 1950s. Since then more than 100 sites have contributed to the average in some years (Dyurgerov 2002, Dyurgerov and Meier 2005). Error bars indicate the standard error in the mean.

Other observations, based on glacier length records, suggest that glacier retreat has occurred nearly continuously since the early 1800s and the end of the little ice age, but variations in rate have occurred, including a significant acceleration during the twentieth century that is believed to have been a response to global warming (Oerlemans 2005).

These measurements are described in Dyurgerov (2002), updated in Dyurgerov and Meier (2005), and archived at the World Glacier Monitoring Service at the National Snow and Ice Data Center. [1] cópia arquivada at the Wayback Machine [2]

This figure was prepared by Robert A. Rohde from published data and is part of 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.

É concedida permissão para copiar, distribuir e/ou modificar este documento nos termos da Licença de Documentação Livre GNU, versão 1.2 ou qualquer versão posterior publicada pela Free Software Foundation; sem Secções Invariantes, sem textos de Capa e sem textos de Contra-Capa. É incluída uma cópia da licença na secção intitulada GNU Free Documentation License.http://www.gnu.org/copyleft/fdl.htmlGFDLGNU Free Documentation Licensetruetrue

	A utilização deste ficheiro é regulada nos termos da licença Creative Commons - Atribuição-CompartilhaIgual 3.0 Não Adaptada.
	Pode: partilhar – copiar, distribuir e transmitir a obra recombinar – criar obras derivadas De acordo com as seguintes condições: atribuição – Tem de fazer a devida atribuição da autoria, fornecer uma hiperligação para a licença e indicar se foram feitas alterações. Pode fazê-lo de qualquer forma razoável, mas não de forma a sugerir que o licenciador o apoia ou subscreve o seu uso da obra. partilha nos termos da mesma licença – Se remisturar, transformar ou ampliar o conteúdo, tem de distribuir as suas contribuições com a mesma licença ou uma licença compatível com a original.
	Esta marca de licenciamento foi adicionada a este ficheiro durante a atualização da licença GFDL.http://creativecommons.org/licenses/by-sa/3.0/CC BY-SA 3.0Creative Commons Attribution-Share Alike 3.0truetrue

• Dyurgerov, Mark B. (2002). "Glacier Mass Balance and Regime: Data of Measurements and Analysis". Institute of Arctic and Alpine Research, Occasional Paper 55.
• 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.
• J. Oerlemans (2005). "Extracting a Climate Signal from 169 Glacier Records". Science 308 (5722): 675-677. DOI:10.1126/science.1107046.

File:Glacier Mass Balance vector.svg é uma versão vetorial deste ficheiro. Ela deve ser usada em vez desta imagem em formato raster, se não for de qualidade inferior. File:Glacier Mass Balance.png → File:Glacier Mass Balance vector.svg Para mais informações, consulte Ajuda:SVG. Em outras línguas Alemannisch ∙ العربية ∙ беларуская (тарашкевіца) ∙ български ∙ বাংলা ∙ català ∙ нохчийн ∙ čeština ∙ dansk ∙ Deutsch ∙ Ελληνικά ∙ English ∙ British English ∙ Esperanto ∙ español ∙ eesti ∙ euskara ∙ فارسی ∙ suomi ∙ français ∙ Frysk ∙ galego ∙ Alemannisch ∙ עברית ∙ हिन्दी ∙ hrvatski ∙ magyar ∙ հայերեն ∙ Bahasa Indonesia ∙ Ido ∙ italiano ∙ 日本語 ∙ ქართული ∙ 한국어 ∙ lietuvių ∙ македонски ∙ മലയാളം ∙ Bahasa Melayu ∙ မြန်မာဘာသာ ∙ norsk bokmål ∙ Plattdüütsch ∙ Nederlands ∙ norsk nynorsk ∙ norsk ∙ occitan ∙ polski ∙ prūsiskan ∙ português ∙ português do Brasil ∙ română ∙ русский ∙ sicilianu ∙ Scots ∙ slovenčina ∙ slovenščina ∙ српски / srpski ∙ svenska ∙ தமிழ் ∙ ไทย ∙ Türkçe ∙ татарча / tatarça ∙ українська ∙ vèneto ∙ Tiếng Việt ∙ 中文 ∙ 中文（中国大陆） ∙ 中文（简体） ∙ 中文（繁體） ∙ 中文（马来西亚） ∙ 中文（新加坡） ∙ 中文（臺灣） ∙ +/−

 

• 
  Portuguese
• 
  Spanish