Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Unprecedented glacier melting in the Andes blamed on climate change

22.01.2013
Glaciers in the tropical Andes have been retreating at increasing rate since the 1970s, scientists write in the most comprehensive review to date of Andean glacier observations.
The researchers blame the melting on rising temperatures as the region has warmed about 0.7°C over the past 50 years (1950-1994). This unprecedented retreat could affect water supply to Andean populations in the near future. These conclusions are published today in The Cryosphere, an Open Access journal of the European Geosciences Union (EGU).

The international team of scientists – uniting researchers from Europe, South America and the US – shows in the new paper that, since the 1970s, glaciers in tropical Andes have been melting at a rate unprecedented in the past 300 years. Globally, glaciers have been retreating at a moderate pace as the planet warmed after the peak of the Little Ice Age, a cold period lasting from the 16th to the mid-19th century. Over the past few decades, however, the rate of melting has increased steeply in the tropical Andes. Glaciers in the mountain range have shrunk by an average of 30-50% since the 1970s, according to Antoine Rabatel, researcher at the Laboratory for Glaciology and Environmental Geophysics in Grenoble, France, and lead author of the study.

Glaciers are retreating everywhere in the tropical Andes, but the melting is more pronounced for small glaciers at low altitudes, the authors report. Glaciers at altitudes below 5,400 metres have lost about 1.35 metres in ice thickness (an average of 1.2 metres of water equivalent [see note]) per year since the late 1970s, twice the rate of the larger, high-altitude glaciers.
“Because the maximum thickness of these small, low-altitude glaciers rarely exceeds 40 metres, with such an annual loss they will probably completely disappear within the coming decades,” says Rabatel.

The researchers further report that the amount of rainfall in the region did not change much over the past few decades and, therefore, cannot account for changes in glacier retreat. Instead, climate change is to blame for the melting: regional temperatures increased an average of 0.15°C per decade over the 1950-1994 period.

“Our study is important in the run-up to the next IPCC report, coming out in 2013,” says Rabatel. The Intergovernmental Panel on Climate Change (IPCC) has pointed out that tropical glaciers are key indicators of recent climate change as they are particularly sensitive to temperature changes. The tropical Andes host 99% of all tropical glaciers in the world, most of them in Peru.

The research is also important to anticipate the future behaviour of Andean glaciers and the impact of their accelerated melting on the region. “The ongoing recession of Andean glaciers will become increasingly problematic for regions depending on water resources supplied by glacierised mountain catchments, particularly in Peru,” the scientists write. Without changes in precipitation, the region could face water shortages in the future.
The Santa River valley in Peru will be most affected, as its hundreds of thousands of inhabitants heavily rely on glacier water for agriculture, domestic consumption, and hydropower. Large cities, such as La Paz in Bolivia, could also face shortages. “Glaciers provide about 15% of the La Paz water supply throughout the year, increasing to about 27% during the dry season,” says Alvaro Soruco, a Bolivian researcher who took part in the study.

In their comprehensive review of Andean glaciers, the scientists synthesised data collected over several decades, some dating as far back as the 1940s. “The methods we used to monitor glacier changes in this region include field observations of glacier mass balance, and remote-sensing measurements based on aerial photographs and satellite images for glacier surface and volume changes,” explains Rabatel.
The study takes into account data collected for glaciers in Colombia, Ecuador, Peru and Bolivia, covering a total of almost a thousand square kilometres. This corresponds to about 50% of the total area covered by glaciers in the tropical Andes in the early 2000s.

The research was conducted to provide the scientific community with a comprehensive overview of the status of glaciers in the tropical Andes and determine the rate of retreat and identify potential causes for the melting. But the authors hope the results can have a wider impact.

“This study has been conducted with scientific motivations, but if the insight it provides can motivate political decisions to mitigate anthropogenic impact on climate and glacier retreat, it will be an important step forward,” Rabatel concludes.

*Note*
Glacier mass balance is the difference between ice accumulation and ablation (melting and sublimation) in a glacier. Scientists express the annual mass balance in metre water equivalent (m w.e.). A loss of 1.2 m w.e. corresponds to a reduction of about 1.35 metres in ice thickness.
*More information*
This research is presented in the paper ‘Current state of glaciers in the tropical Andes: a multi-century perspective on glacier evolution and climate change’ to appear in the EGU Open Access journal The Cryosphere on 22 January 2013.

The peer-reviewed scientific article is available online, from the publication date onwards, at http://www.the-cryosphere.net/recent_papers.html. Please contact the EGU Media and Communications Officer if you would like the final version of the paper before the publication date.

The discussion paper (before peer review) and reviewers comments is available at

http://www.the-cryosphere-discuss.net/6/2477/2012/tcd-6-2477-2012-discussion.html

The team is composed of A. Rabatel (Laboratory of Glaciology and Geophysics of the Environment [LGGE], Joseph Fourier University, Grenoble, France), B. Francou (Laboratory for the Study of Transfers in Hydrology and Environment [LTHE], Joseph Fourier University, Grenoble, France), A. Soruco (Institute of Geological and Environmental Research, Universidad Mayor de San Andres [IGEMA-UMSA], La Paz, Bolivia), J. Gomez (National Water Authority, Glaciology and Water Resources Unit [ANA-UGRH], Huaraz, Peru), B. Cáceres (National Institute of Meteorology and Hydrology [INAMHI], Quito, Ecuador), J. L. Ceballos (Institute of Hydrology, Meteorology and Environmental Studies [IDEAM], Bogotá, Colombia), R. Basantes (LTHE -and- Department of Civil and Environmental Engineering, National Politechnic School [DICA-EPN], Quito, Ecuador), M. Vuille (Department of Atmospheric and Environmental Sciencies, University of Albany, New York, USA), J.-E. Sicart (LTHE), C. Huggel and M. Scheel (Department of Geography, University of Zurich, Switzerland), Y. Lejeune (Snow Research Centre, National Centre for Meteorological Research (CEN CNRM-GAME), Saint Martin d'Hères, France), Y. Arnaud (LTHE), M. Collet (LTHE -and- DICA-EPN), T. Condom (LTHE), G. Consoli (LTHE), V. Favier (LGGE), V. Jomelli (Laboratory of Physical Geography (LPG), University of Paris-Sud, Paris, France), R. Galarraga (DICA-EPN), P. Ginot (LGGE -and- Grenoble Observatory for the Sciences of the Universe (OSUG), Grenoble, France), L. Maisincho (INAMHI), J. Mendoza (Institute of Hydraulics and Hydrology, UMSA [IHH-UMSA], La Paz, Bolivia), M. Ménégoz (LGGE), E. Ramirez (IHH-UMSA), P. Ribstein (Sisyphe, University Pierre and Marie Curie, Paris, France), W. Suarez (National Service of Meteorology and Hydrology (SENAMHI), Lima, Peru), M. Villacis (DICA-EPN), and P. Wagnon (LTHE). Most of these researchers are members of the International Joint Laboratory GREAT-ICE, an initiative of the French Institute of Research for Development (IRD) and universities and institutions in Bolivia, Peru, Ecuador, and Colombia.

The European Geosciences Union (www.egu.eu) is Europe’s premier geosciences union, dedicated to the pursuit of excellence in the Earth, planetary, and space sciences for the benefit of humanity, worldwide. It is a non-profit interdisciplinary learned association of scientists founded in 2002. The EGU has a current portfolio of 14 diverse scientific journals, which use an innovative open-access format, and organises a number of topical meetings, and education and outreach activities. Its annual General Assembly is the largest and most prominent European geosciences event, attracting over 10,000 scientists from all over the world. The meeting’s sessions cover a wide range of topics, including volcanology, planetary exploration, the Earth’s internal structure and atmosphere, climate, energy, and resources. The 2013 EGU General Assembly is taking place is Vienna, Austria from 7-12 April. For information regarding the press centre at the meeting and media registration, please check http://media.egu.eu.

Contacts
Antoine Rabatel
Laboratory for Glaciology and Environmental Geophysics
Grenoble, France
Tel: +33-4-7682-4271
Email: rabatel@lgge.obs.ujf-grenoble.fr

Bárbara Ferreira
EGU Media and Communications Officer
Munich, Germany
Tel: +49-89-2180-6703
Email: media@egu.eu

Dr. Bárbara Ferreira | European Geosciences Union (EGU)
Further information:
http://www.egu.eu
http://www.egu.eu/news/55/unprecedented-glacier-melting-in-the-andes-blamed-on-climate-change/

More articles from Earth Sciences:

nachricht GPM sees deadly tornadic storms moving through US Southeast
01.12.2016 | NASA/Goddard Space Flight Center

nachricht Cyclic change within magma reservoirs significantly affects the explosivity of volcanic eruptions
30.11.2016 | Johannes Gutenberg-Universität Mainz

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Greifswalder Forscher dringen mit superauflösendem Mikroskop in zellulären Mikrokosmos ein

Das Institut für Anatomie und Zellbiologie weiht am Montag, 05.12.2016, mit einem wissenschaftlichen Symposium das erste Superresolution-Mikroskop in Greifswald ein. Das Forschungsmikroskop wurde von der Deutschen Forschungsgemeinschaft (DFG) und dem Land Mecklenburg-Vorpommern finanziert. Nun können die Greifswalder Wissenschaftler Strukturen bis zu einer Größe von einigen Millionstel Millimetern mittels Laserlicht sichtbar machen.

Weit über hundert Jahre lang galt die von Ernst Abbe 1873 publizierte Theorie zur Auflösungsgrenze von Lichtmikroskopen als ein in Stein gemeißeltes Gesetz....

Im Focus: Durchbruch in der Diabetesforschung: Pankreaszellen produzieren Insulin durch Malariamedikament

Artemisinine, eine zugelassene Wirkstoffgruppe gegen Malaria, wandelt Glukagon-produzierende Alpha-Zellen der Bauchspeicheldrüse (Pankreas) in insulinproduzierende Zellen um – genau die Zellen, die bei Typ-1-Diabetes geschädigt sind. Das haben Forscher des CeMM Forschungszentrum für Molekulare Medizin der Österreichischen Akademie der Wissenschaften im Rahmen einer internationalen Zusammenarbeit mit modernsten Einzelzell-Analysen herausgefunden. Ihre bahnbrechenden Ergebnisse werden in Cell publiziert und liefern eine vielversprechende Grundlage für neue Therapien gegen Typ-1 Diabetes.

Seit einigen Jahren hatten sich Forscher an diesem Kunstgriff versucht, der eine simple und elegante Heilung des Typ-1 Diabetes versprach: Die vom eigenen...

Im Focus: Makromoleküle: Mit Licht zu Präzisionspolymeren

Chemikern am Karlsruher Institut für Technologie (KIT) ist es gelungen, den Aufbau von Präzisionspolymeren durch lichtgetriebene chemische Reaktionen gezielt zu steuern. Das Verfahren ermöglicht die genaue, geplante Platzierung der Kettengliedern, den Monomeren, entlang von Polymerketten einheitlicher Länge. Die präzise aufgebauten Makromoleküle bilden festgelegte Eigenschaften aus und eignen sich möglicherweise als Informationsspeicher oder synthetische Biomoleküle. Über die neuartige Synthesereaktion berichten die Wissenschaftler nun in der Open Access Publikation Nature Communications. (DOI: 10.1038/NCOMMS13672)

Chemische Reaktionen lassen sich durch Einwirken von Licht bei Zimmertemperatur auslösen. Die Forscher am KIT nutzen diesen Effekt, um unter Licht die...

Im Focus: Neuer Sensor: Was im Inneren von Schneelawinen vor sich geht

Ein neuer Radarsensor erlaubt Einblicke in die inneren Vorgänge von Schneelawinen. Entwickelt haben ihn Ingenieure der Ruhr-Universität Bochum (RUB) um Dr. Christoph Baer und Timo Jaeschke gemeinsam mit Kollegen aus Innsbruck und Davos. Das Messsystem ist bereits an einem Testhang im Wallis installiert, wo das Schweizer Institut für Schnee- und Lawinenforschung im Winter 2016/17 Messungen damit durchführen möchte.

Die erhobenen Daten sollen in Simulationen einfließen, die das komplexe Geschehen im Inneren von Lawinen detailliert nachbilden. „Was genau passiert, wenn sich...

Im Focus: Neuer Rekord an BESSY II: 10 Millionen Ionen erstmals bis auf 7,4 Kelvin gekühlt

Magnetische Grundzustände von Nickel2-Ionen spektroskopisch ermittelt

Ein internationales Team aus Deutschland, Schweden und Japan hat einen neuen Temperaturrekord für sogenannte Quadrupol-Ionenfallen erreicht, in denen...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

Von „Coopetition“ bis „Digitale Union“ – Die Fertigungsindustrien im digitalen Wandel

02.12.2016 | Veranstaltungen

Experten diskutieren Perspektiven schrumpfender Regionen

01.12.2016 | Veranstaltungen

Die Perspektiven der Genom-Editierung in der Landwirtschaft

01.12.2016 | Veranstaltungen

 
VideoLinks
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Parkinson-Krankheit und Dystonien: DFG-Forschergruppe eingerichtet

02.12.2016 | Förderungen Preise

Smart Data Transformation – Surfing the Big Wave

02.12.2016 | Studien Analysen

Nach der Befruchtung übernimmt die Eizelle die Führungsrolle

02.12.2016 | Biowissenschaften Chemie