The global retreat of glaciers has accelerated in the last two decades. Despite the fact that their contraction has already been evident to us for quite some time, new research raises the alarm: since 2000 the melting of the Earth’s glaciers has accelerated, reaching losses of 298,000 tons of ice between 2015 and 2019 , compared to the 227 billion tonnes of ice lost between 2000 and 2004.
Accelerated melting
An international team of researchers led by scientists from the Laboratory for the Study of Space Geophysics and Oceanography of the French National Center for Scientific Research (CNRS) has used detailed satellite observations to study 217,175 glaciers around the world (almost all glaciers on Earth). ), excluding ice sheets. These estimates were validated with independent, high-precision measurements of individual glaciers. With all this data, the scientists were able to calculate the changes in the volume and mass of the glaciers . Data that revealed the dramatic decline seen among glaciers in the 21st century: glacier mass loss has accelerated to 48 billion tons per year every decade since 2000.
Glacier shrinkage has been precipitous in recent years. No doubt.
Experts found that between 2000 and 2019, glaciers collectively lost an average of 293.7 billion tons (267 billion metric tons) of mass per year; this represents about 21% of the observed rise in sea level in that time period , the authors noted in their study published in the journal Nature .
“Glacier mass loss has accelerated to 48 gigatons per year every decade since 2000, which could explain between 6% and 19% of the observed acceleration of sea level rise.” In particular, the researchers identified seven regions that accounted for 83% of glacier mass loss : Alaska, with a loss of 25%, the periphery of Greenland, with a reduction of 13%, the north and south of the Canadian Arctic. , with 10% each, Antarctica and subantarctic province, high mountain Asia and the Southern Andes, with 8% loss of mass each.
The team estimates that the rise in sea level due to melting glaciers has been on the order of 0.74 millimeters . The rest is due to melting of the Greenland and Antarctic ice sheets, changes in the way water is stored on the planet, and the thermal expansion of water across the planet in response to higher average temperatures.
Looking to the future
By tracking how quickly glaciers are shrinking, scientists can better predict how quickly sea levels may rise, especially as climate change increases average global temperatures across our planet. Rising sea levels could have devastating implications for millions of people living in coastal regions and also for wildlife , because glacier mass loss can alter nearby bodies of water and the availability of water resources, as well as the possibility of natural disasters such as avalanches or catastrophic floods.
Referencia: Accelerated global glacier mass loss in the early twenty-first century, Nature (2021). DOI: 10.1038/s41586-021-03436-z
