crédit photo : © Pierre Pitte / LEGOS
Glacier melt: mapping reveals the acceleration
Share the post "Glacier melt: mapping reveals the acceleration"
by CNRS*, CNES* and IRD*, April 2021
Glaciers around the world are melting at a record rate due to global warming. Recent studies have shown that global losses have accelerated in recent years, from 227 gigatonnes of ice lost per year between 2000 and 2004 to 298 gigatonnes per year between 2015 and 2019.
But the data on this phenomenon remained incomplete. Thanks to satellite observations, an international team has just delivered the most complete and precise analysis of the evolution of all these glaciers. This study, published in the journal Nature on 28 April 2021, confirms that their loss of mass has been accelerating since the 2000s.
An important amount of satellite data, since the year 2000
An international team involving scientists from the CNRS*, the University of Toulouse III – Paul Sabatier, with the support of the CNES* and the IRD* has just published its results on the analysis of the melting of the world’s glaciers. It has used nearly half a million images taken since 2000 by the Terra satellite!
This satellite regularly acquires pairs of images of the Earth’s surface using two cameras, which has made it possible to create a series of digital models of glacier elevation. The spatial and temporal accuracy of these results is unprecedented.
This new study shows that since 2000, glaciers have been losing an average of 267 billion tonnes of ice per year and that the melting is accelerating.
The fastest melting glaciers are located in the Alps, Iceland and Alaska. Melt rates slowed down between 2010 and 2019 on the east coast of Greenland, Iceland and Scandinavia. This local deceleration could be due to a weather anomaly that has caused higher precipitation and lower temperatures, slowing down ice loss.
Decadal and regional variability in mass loss is largely controlled by changes in precipitation. In contrast, the overall acceleration in glacier mass loss is a result of rising temperatures.
These new observations will help refine projections of future glacier evolution, which could, for example, contribute to better anticipation of changes in water resources in certain mountain regions.
Référence:
« Accelerated global glacier mass loss in the early twenty-first century » : Hugonnet, R., McNabb, R., Berthier, E., Menounos, B., Nuth, C., Girod, L., Farinotti, D., Huss, M., Dussaillant, I., Brun, F., et Kääb, A. – Revue Nature, le 29 avril 2021, doi:10.1038/s41586-021-03436-z
*CNRS : Centre National de la Recherche Scientifique
*CNES : Centre National d’Études Spatiales
*IRD : Institut de Recherche pour le Développement
Sophie Bonnet, French Researcher Awarded an Exceptional European Research Grant
Sophie Bonnet is Director of Research at the Mediterranean Institute of Oceanology (MIO Aix-Marseille University, CNRS, IRD, University of Toulon). She has just won an exceptional European grant for an innovative research project that will examine the biological mechanisms of CO2 sequestration by the ocean, from the study of the cell to the ecosystem as a whole.
Is the Mediterranean Sea running out of steam?
Last June, the 10th oceanographic campaign of the MOOSE network took place in the Mediterranean Sea. For more than a decade, the LOCEAN laboratory, the marine stations of Roscoff, Banyuls, Villefranche-sur-mer of Sorbonne University, the MIO laboratory and CEFREM have been involved in this Mediterranean Ocean Observing System for the Environment financed by CNRS-INSU and the ILICO Research Infrastructure.
The Oceanic Carbon Pump
The ocean is a climate regulator, mainly because it captures ⅓ of the carbon dioxide (CO2) emitted into the atmosphere each year. This phenomenon of "oceanic carbon pump" is due to a double process: a physical process and a biological process.
OneOceanScience: tackling climate change through ocean science
On 25 October, Ifremer, CNRS and IRD (Institut de Recherche pour le Développement) launched a digital world tour of ocean and climate sciences, called OneOceanScience, with the support of Thomas Pesquet but also the European Space Agency (ESA) and the Ocean and Climate Platform.
Participatory science to measure water resources in the Pyrenees
February and April: this winter of 2021 saw new waves of sand from the Sahara covering the snow cover in the Alps and the Pyrenees.
Glacier melt: mapping reveals the acceleration
Glaciers around the world are melting at a record rate due to global warming. Recent studies have shown that global losses have accelerated in recent years, from 227 gigatonnes of ice lost per year between 2000 and 2004 to 298 gigatonnes per year between 2015 and 2019.
The Southern Ocean is warming at depth
An international team of scientists has unveiled analyses of the rise in Antarctic temperatures over the past 25 years. A study that sounds like a wake-up call.
share the article on social media