Previously Unknown Loss of Antarctic Ice Discovered by NASA – “Antarctica Is Crumbling at Its Edges”

Getz Ice Shelf in West Antarctica

The 200-foot-tall (60-meter-tall) front of the Getz Ice Shelf in Antarctica is scored with cracks where icebergs are likely to break off, or calve, in this 2016 photo. The first estimate of Antarctic calving has found that since 1997 ice shelves have lost as much ice from calving as from melting. Credit: NASA/GSFC/OIB/Jeremy Harbeck

New NASA research on Antarctica, including the first map of iceberg calving, doubles the previous estimates of loss from ice shelves and details how the continent is changing.

In forecasting global sea level rise, the greatest uncertainty is how Antarctica’s ice loss will accelerate as the climate warms. Two studies led by researchers at NASA’s Jet Propulsion Laboratory (JPL) in Southern California reveal unexpected new data about how the Antarctic Ice Sheet has been losing mass in recent decades.

“Antarctica is crumbling at its edges.” — Chad Greene

One study, published recently in the journal Nature, maps how iceberg calving – the breaking off of ice from a glacier front – has changed the Antarctic coastline over the last 25 years. The scientists found that the edge of the ice sheet has been shedding icebergs faster than the ice can be replaced. This surprising finding doubles previous estimates of ice loss from the Antarctic’s floating ice shelves since 1997, from 6 trillion to 12 trillion metric tons. Ice loss from calving has weakened the ice shelves, allowing Antarctic glaciers to flow more rapidly to the ocean and accelerating the rate of global sea level rise.

The other study, published recently in the journal Earth System Science Data, shows in unprecedented detail how the thinning of Antarctic ice as ocean water melts it has spread from the continent’s outward edges into its interior, almost doubling in the western parts of the ice sheet over the past decade. Combined, the complementary reports provide the most complete view yet of how the frozen continent is changing.

Iceberg Calving

“Antarctica is crumbling at its edges,” says JPL scientist Chad Greene, lead author of the calving study. “And when ice shelves dwindle and weaken, the continent’s massive glaciers tend to speed up and increase the rate of global sea level rise.”

Most Antarctic glaciers flow to the ocean, where they end in floating ice shelves that are up to 2 miles (3 kilometers) thick and 500 miles (800 kilometers) across. Ice shelves act like buttresses to glaciers, keeping the ice from simply sliding into the ocean. When ice shelves are stable, they have a natural cycle of calving and replenishment that maintains their size fairly consistently over the long term.

Antarctic Ice Sheet Elevation Map

Changes in elevation of the Antarctic ice sheet from 1985 to 2021 are shown. Ice height diminishes (red) as the ice sheet melts by contact with ocean water; it rises (blue) where accumulation exceeds melting. Ice shelves are shown in gray. The missions that supplied data are listed at the bottom. Credit: NASA/JPL-Caltech

However, in recent decades, the warming ocean has been destabilizing Antarctica’s ice shelves by melting them from below, making them thinner and weaker. Although satellite altimeters measure the thinning process by recording the changing height of the ice, until this study, there hasn’t been a comprehensive assessment of how climate change might be affecting calving around the continent.

Part of the reason is that satellite imagery has been challenging to interpret. “For example, you can imagine looking at a satellite image and trying to figure out the difference between a white iceberg, white ice shelf, white sea ice, and even a white cloud,” said Greene. “That’s always been a difficult task. But we now have enough data from multiple satellite sensors to see a clear picture of how Antarctica’s coastline has evolved in recent years.”

For the new study, Greene and his colleagues synthesized satellite imagery of the continent in visible, thermal infrared (heat), and radar wavelengths since 1997. Combining these measurements with an understanding of ice flow gained from an ongoing NASA glacier-mapping project, they charted the edges of ice shelves around 30,000 linear miles (50,000 kilometers) of the Antarctic coastline.

Because losses from calving have outpaced natural ice-shelf growth so greatly, the researchers think it’s unlikely Antarctica can grow back to its pre-2000 extent by the end of this century. In fact, the findings suggest that greater losses can be expected: All of Antarctica’s largest ice shelves appear to be headed for major calving events in the next 10 to 20 years.

Mapping 36 Years of Ice Loss

In the complementary study, JPL scientists combined almost 3 billion data points from seven spaceborne altimetry instruments to produce the longest continuous data set on the changing height of the ice sheet – an indicator of ice loss – from as early as 1985. They utilized radar and laser measurements of ice elevation, accurate to within centimeters, to produce the highest-resolution monthly maps of change ever made of ice loss.

Hundreds of meltwater lakes hide deep beneath the expanse of Antarctica’s ice sheet. With a powerful laser altimeter system in space, NASA’s Ice Cloud and land Elevation Satellite-2 (ICESat-2) is helping scientists “see” under the ice.

The unparalleled detail in the new record demonstrates how long-term trends and annual weather patterns affect the ice. It even depicts the rise and fall of the ice sheet as subglacial lakes regularly fill and empty (see video above) miles below the surface. “Subtle changes like these, in combination with an improved understanding of long-term trends from this data set, will help researchers understand the processes that influence ice loss, leading to improved future estimates of sea level rise,” said JPL’s Johan Nilsson, lead author of the study.

Synthesizing and analyzing the massive archives of measurements into a single, high-resolution data set took years of work and thousands of hours of computing time on NASA’s servers. According to Nilsson, it was all worth it: “Condensing the data into something more widely useful may bring us closer to the big breakthroughs we need to better understand our planet and to help prepare us for the future impacts of climate change.”


“Antarctic calving loss rivals ice-shelf thinning” by Chad A. Greene, Alex S. Gardner, Nicole-Jeanne Schlegel and Alexander D. Fraser, 10 August 2022, Nature.
DOI: 10.1038/s41586-022-05037-w

“Elevation change of the Antarctic Ice Sheet: 1985 to 2020” by Johan Nilsson, Alex S. Gardner and Fernando S. Paolo, 10 August 2022, Earth System Science Data.
DOI: 10.5194/essd-14-3573-2022

9 Comments on "Previously Unknown Loss of Antarctic Ice Discovered by NASA – “Antarctica Is Crumbling at Its Edges”"

  1. “Antarctica is crumbling at its edges,”

    More accurately, Western Antarctica is crumbling at its edges, not the whole continent.

    “… until this study, there hasn’t been a comprehensive assessment of how climate change might be affecting calving around the continent.”

    And, there still isn’t because the study doesn’t even acknowledge — let alone answer — the question of why the melting is only happening in Western Antarctica and NOT Eastern Antarctica. The presumption of global warming (aka climate change) is that changes in the concentration of well-mixed CO2 in the atmosphere is having a global effect, not just local. All the ice terminates in the oceans. Is it coincidence that the greatest loss is occurring where a new volcanic province has been discovered, apparently an extension of the Pacific Ring of Fire?
    The oceans may be warming, but because of the large specific heat capacity of water, compared to other materials, it should only be warming at about 1/4 the rate of the air over land, which globally is only about 1 deg C in the last 100 years.

  2. William Johnson | September 6, 2022 at 7:11 am | Reply

    My understanding is that ANTARCTICA many ‘millions of years long past’ enjoyed “a semi-tropical climate”. Perhaps these ‘glacial events’ are the prelude to ‘a return to former times’ for ‘the Continent’…which could prove to be a ‘good thing’ for ‘future generations’ on Our Planet 🌎 EARTH…!

    • Wrong. Abrupt exponential climate change is never a good thing and is quickly driving the human race to extinction…within 3-4 years. One must study and consider the aggregate of the peer reviewed scientific literature, not cherry pick a single study and draw a conclusion. That is ridiculous. The planet is now well over 2 deg C warming from the proper 1750’s baseline. The IPCC moved the goal pasts to make the data more palatable to the politicians and the media. Scientific prediction models were deeply flawed. Phenomena predicted to occur in 2100 is happening NOW. A better place to look at climate change’s impacts to ice is the Arctic Sea ice, which is almost completely gone. This itself is an ominous portent of what is quickly approaching the human race.

      • “… is quickly driving the human race to extinction…within 3-4 years.”

        I do hope that you have the courage of your convictions and are spending all your savings, and maybe even going into debt, to enjoy your last 4 years.

      • “A better place to look at climate change’s impacts to ice is the Arctic Sea ice, which is almost completely gone.”

        Not so. The Arctic sea ice coverage is about the same as last year, and is considerably higher than the low reached in 2012.
        See Fig. 2A at
        The link states, “Summer in the Arctic is drawing to a close, and sea ice extent is likely to remain higher than in recent years.”

  3. Lies here’s proof Arctic-Wide Glaciers And Ice Caps Were Absent Or Smaller Than Today From 10,000 To 3000 Years Ago

  4. There is a constant drone of talk about how much carbon dioxide we’ve been creating, but when was the last time anyone suggested that we monitor the carbon dioxide we’re failing to capture due in large part from third world deforestation? Forests are the transformers of carbon dioxide into oxygen and the last gasp of breath we’ll take is when we decimate the last forest.

  5. Where I live in central Florida, they are bulldozing trees and habitat to build thousands and thousands of new houses. On top of what they’ve built the last few years, which has been uncontrolled growth, there are 16,000 existing new building permits in Haines City alone. With what I’ve seen of this destruction sanctioned by the government, I never want to hear about this crap again. If it were this urgent, this would not be happening.

  6. Rubbish, we are bombarded with these same hoax predictions year after year decade after decade .

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