By combining climate and glacier models, scientists headed by Ben Marzeion from the University of Innsbruck have found unambiguous evidence for anthropogenic glacier mass loss in recent decades.
In a paper published in Science, the researchers report that about one quarter of the global glacier mass loss during the period of 1851 to 2010 is attributable to anthropogenic causes. The fraction of human contribution increased steadily and accelerated to almost two thirds between 1991 and 2010.
The ongoing global glacier retreat causes rising sea-levels, changing seasonal water availability and increasing geo-hazards. While melting glaciers have become emblematic of anthropogenic climate change, glacier extent responds very slowly to climate changes.
“Typically, it takes glaciers decades or centuries to adjust to climate changes,” says climate researcher Ben Marzeion from the Institute of Meteorology and Geophysics of the University of Innsbruck. The global retreat of glaciers observed today started around the middle of the 19th century at the end of the Little Ice Age. Glaciers respond both to naturally caused climate change of past centuries, for example solar variability, and to anthropogenic changes. The real extent of human contribution to glacier mass loss has been unclear until now.
By using computer simulations of the climate, Ben Marzeion’s team of researchers simulated glacier changes during the period of 1851 and 2010 in a model of glacier evolution. “The results of our models are consistent with observed glacier mass balances,” says Marzeion.
All glaciers in the world outside Antarctica were included in the study. The recently established Randolph Glacier Inventory (RGI), a complete inventory of all glaciers worldwide, enabled the scientists to run their model. “The RGI provides data of nearly all glaciers on the Earth in machine-readable format,” explains Graham Cogley from Trent University in Canada, one of the coordinators of the RGI and co-author of the current study.
Since the climate researchers are able to include different factors contributing to climate change in their model, they can differentiate between natural and anthropogenic influences on glacier mass loss. “While we keep factors such as solar variability and volcanic eruptions unchanged, we are able to modify land use changes and greenhouse gas emissions in our models,” says Ben Marzeion, who sums up the study: “In our data we find unambiguous evidence of anthropogenic contribution to glacier mass loss.”
Significant increase in recent decades
The scientists show that only about one quarter (25 +/-35 %) of the global glacier mass loss during the period of 1851 to 2010 is attributable to anthropogenic causes. However, during the last two decades between 1991 and 2010 the fraction increased to about two thirds (69+/-24%).
“In the 19th and first half of 20th century we observed that glacier mass loss attributable to human activity is hardly noticeable but since then has steadily increased,” says Ben Marzeion. The authors of the study also looked at model results on regional scales.
However, the current observation data is insufficient in general to derive any clear results for specific regions, even though anthropogenic influence is detectable in a few regions such as North America and the Alps. In these regions, glaciers changes are particularly well documented.
The study is supported, among others, by the Austrian Science Fund (FWF) and the research area Scientific Computing at the University of Innsbruck.
Publication: Attribution of global glacier mass loss to anthropogenic and natural causes. Ben Marzeion, J. Graham Cogley, Kristin Richter, & David Parkes. Science Express, published online August 14 2014 DOI: 10.1126/science.1254702
Priv.-Doz. Dr. Ben Marzeion
Institut für Meteorologie und Geophysik
phone: +43 512 507-5482
University of Innsbruck
phone: +43 512 507 32022
http://dx.doi.org/10.1126/science.1254702 - Attribution of global glacier mass loss to anthropogenic and natural causes. Ben Marzeion, J. Graham Cogley, Kristin Richter, & David Parkes. Science Express, published online August 14 2014
http://www.marzeion.info - Website Ben Marzeion
http://www.uibk.ac.at/meteo - Institute of Meteorology and Geophysics, University of Innsbruck
Dr. Christian Flatz | Universität Innsbruck
How much biomass grows in the savannah?
16.02.2017 | Friedrich-Schiller-Universität Jena
Canadian glaciers now major contributor to sea level change, UCI study shows
15.02.2017 | University of California - Irvine
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
17.02.2017 | Medical Engineering
17.02.2017 | Medical Engineering
17.02.2017 | Health and Medicine