Environment

Glaciers have lost 9 trillion tonnes of ice since 1961, says satellite study

Glaciers in Northeast India, captured on December 6, 2018
Glaciers in Northeast India, captured on December 6, 2018
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A chart illustrating the glacial ice loss of different regions around the world between 1961 and 2016
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A chart illustrating the glacial ice loss of different regions around the world between 1961 and 2016
Glaciers in Northeast India, captured on December 6, 2018
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Glaciers in Northeast India, captured on December 6, 2018

It's no secret that glaciers are becoming rarer and smaller in our warming world, but it's hard to understand the extent of that ice loss. Now, a comprehensive study has put a number to it, by combining field observations on the ground and satellite data. The team found that between 1961 and 2016, glaciers globally lost a total of over 9 trillion tonnes of ice, contributing significantly to sea level rise.

The biggest loser of that 55-year period was Alaska, which is down more than 3 trillion tonnes of glacial ice. Greenland comes in second, having shed 1.237 trillion tonnes, followed closely by the Southern Andes at 1.208 trillion. The Russian and Canadian Arctic regions also lost over a trillion tonnes each.

A chart illustrating the glacial ice loss of different regions around the world between 1961 and 2016
A chart illustrating the glacial ice loss of different regions around the world between 1961 and 2016

Of the 19 glacierized regions studied, only one actually gained ice during that time. Southwest Asia managed to put on an extra 119 billion tonnes of ice. Unfortunately that's a mere drop in the ocean – after all, the neighboring region of Southeast Asia effectively canceled it out by losing 112 billion tonnes.

And all that ice has to go somewhere. Melting glacial ice is considered the second-biggest contributing factor to rising sea levels, after warming waters. In this case, the team calculated that glacial ice loss has raised the global sea level by 27 mm (1 in) in that time. Worse still, these processes seem to be speeding up.

"While we can now offer clear information about how much ice each region with glaciers has lost, it is also important to note that the rate of loss has increased significantly over the last 30 years," says Michael Zemp, lead researcher on the study. "We are currently losing a total of 335 billion tonnes of ice a year, corresponding to a rise in sea levels of almost 1 mm per year."

To make these calculations, the team examined 19,000 individual glaciers in 19 regions around the world, estimating the changes in ice thickness over the past half-century. The outlines of glaciers were provided from satellite data from the ESA's Climate Change Initiative and GlobGlacier project. Other satellites provided topographical data that helped the team build digital elevation models, along with measurements taken from ground teams over the decades.

Glacial ice loss is important to track for many reasons. A better understanding of the mechanisms behind it helps scientists build more accurate climate models, and can help in the planning for run-on disasters, such as floods or water shortages after they're gone.

The study was published in the journal Nature.

Source: ESA

13 comments
Wastewater Al
Gee and I have put on nearly 90 kg since 1961 I wish i could use the Glacial Diet and melt a bit away.
Rumata
Wow. That means 26mm sea level rise since 1961. It translates to 0,45mm rise per year, or 0,45m rise per millenia. No doubt, it will lead to a global catastrophy.
piperTom
The "outlines of glaciers were provided from satellite data" ... starting in 1961? All this sounds very scary, which is the whole point. One can't get grant money without it! Meanwhile, it's one inch; one MORE inch of rise in the trend. Sea level has been rising for 20,000 years. Did we expect it would stop?
JenniferPage
Melting glaciers do not cause sea levels to rise as their mass does not alter. See Archimedes Principle.
aksdad
9 trillion tons of glacier melt is a catastrophe! Translated into 1 inch of sea level rise over 58 years...not so much. @JenniferPage, melting glaciers DO cause sea level to rise. Melting icebergs, Arctic and Antarctic ocean ice pack and ice shelves floating in the ocean do not. That's the "Archimedes principle" that you are talking about. Glaciers and icebergs/ice pack/ice shelves are different things. This article is about glacier melt.
Grumpyrelic
Recently scientists were poking around Ellesmere island and dug up 2 layers of peat, each about 20 ft. thick. probably 3 - 6 million years old. Although the island is at the top of Canada now, then it was situated around Yellowknife within the arctic circle and permafrost land. Yet the peat required an average temperature of +14 C. to survive. That is the same average temperature of Ottawa Canada. So the temperature of Ellesmere Island has been cooling for 3 - 6 million years. elsewhere, NASA has discovered 21 active volcanoes under the ice of Antartica last year. Despite that, the ice pack there has thickened this year. Over millennia, people have blindly followed political, social and religious self-appointed Chicken Littles while they fleeced our bank accounts. Our political leaders believe this carbon crap. It appears they got an expensive education to prepare themselves to lead us. I think their parents should demand their tuition money back.
tsvieps
" "We are currently losing a total of 335 billion tonnes of ice a year, corresponding to a rise in sea levels of almost 1 mm per year." Yikes!! That is almost 4 inches per century. Imagine what damage that might cause when added to a 60 foot tsunami. In truth, what is happening in the antarctic may be more significant and may remain mostly unknown. The article did show some measurement there, however, but it is a large place.
Johannes
OK, here goes... Rumata, if you'd read even just the abstract of the paper in Nature, you'd know that the authors indicate that glacier mass loss has contributed 25 to 30% of observed sea level rise in the period. piperTom, was there something deficient about geographic measurement techniques in 1961? And the most recent equivalent sea level we can refer to is during the Sangamonian interglacial about 125k years ago, and it was about 8 m higher than today, so the grant money explanation doesn't really cut it. JenniferPage, see aksdad's comment, and maybe get an education before commenting. Grumpyrelic, your one proxy data point is infinitesimally small compared to the 450 observations of 19,130 glaciers used by the authors of the Nature paper. FFS, aren't NewAtlas readers even marginally scientifically literate?
Grumpyrelic
I wonder if people are having trouble seeing the forest for the trees in this issue of global warming. Scientists have discovered the remains of forests that lived within both arctic circles on this planet that nobody attempts to explain. Further, many years ago a glacier about 5000 ft thick covered most of North America until it melted but nobody seemed to care when it did. I live in Ottawa, Canada. Earlier this year, climatologists assured us that we would have an "early" spring. These are the people, using Cray Computers that can't provide us with an accurate 24 hour forecast As I sit here typing away on the the computer on April 10, 2019, I look out the window at 2 feet of snow. We have had 148 days of snow on the ground this season. When my son was born 40 years ago this weekend, We picked flowers for his birthday. Thousands of data points taken on a few chunks of ice taken over less than 100 years is not enough time scale to forecast a 4 billion year old planet's weather future. Isn't funny that when we mine resources from the ground, it suddenly becomes polluting trash. If we spent more time managing the resources/trash issue instead of uselessly shaking our fists at the evil sun that melts our precious ice, we would be much better off.
Lamar Havard
Fill a glass full of ice and water to the rim and sit it on a table and see if it overflows as the ice melts...no it doesn't. And neither will the oceans rise as the planet's ice melts...and re-freezes, in the NORMAL cycle. If ice melts in the Arctic, it WILL increase in the Antarctic.