In the unrelenting march of climate alarmism, few narratives are as iconic—or as misleading—as those involving massive Antarctic icebergs. A recent study published in Geophysical Research Letters by MacKie et al. challenges this narrative, using nearly half a century of data to dissect the relationship between iceberg calving and climate change. The study presents findings that are not just counterintuitive to the alarmist narrative, but outright debunk some of its central claims.
Key Findings: No Upward Trend in Iceberg Calving
Using Extreme Value Theory (EVT), MacKie and colleagues analyzed 47 years of satellite data to evaluate trends in Antarctic iceberg calving. The results were clear: there has been no upward trend in the size of the largest icebergs calved annually since 1976. As the study states:
“The risk of experiencing a major calving event has not increased over the last 47 years, which suggests that climate change is not necessarily responsible for the calving of these large icebergs.”.
This is a startling conclusion given the frequent media and activist claims that such events are harbingers of climate doom.
Massive Icebergs: A Natural Phenomenon
The researchers also addressed the stochastic nature of calving events, emphasizing that these are statistically consistent with natural variability. Historical records, including pre-satellite observations, confirm that large iceberg calving has occurred for centuries, well before modern industrialization:
“Historical shipboard records suggest that such massive events predate the onset of notable Antarctic ice shelf decline.”.
Moreover, the iconic A68 iceberg, which broke off from the Larsen C ice shelf in 2017, was found to be statistically unexceptional when compared to historical records. The real peak in extreme calving occurred between 1986 and 2000, with no discernible link to modern climate trends.
The Real Threat: Small Calving Events
While the media tends to focus on photogenic giant icebergs, MacKie et al. highlight that the real driver of Antarctic ice mass loss is the cumulative impact of smaller calving events. These smaller events, rather than large-scale catastrophes, appear to be the primary mechanism by which ice shelves thin and destabilize over time. The study explains this phenomenon as “death by a thousand cuts,” rather than the dramatic collapses often emphasized in climate rhetoric.
Policy Implications: A Reality Check
The findings carry profound implications for climate policy. If extreme calving events are not linked to climate change but are instead part of natural ice shelf dynamics, this undermines the rationale for many expensive mitigation policies targeting such phenomena. Antarctic ice loss—driven by a mix of small calving events and oceanic conditions— will not respond meaningfully to misguided reductions in carbon emissions.
Additionally, the study acknowledges the limitations of current models in predicting these events. The inherent unpredictability of iceberg calving, coupled with the lack of long-term data, makes it nearly impossible to attribute individual events to human activity. As the study notes:
“A comprehensive physical model for calving processes is a complicated and as of yet unrealized endeavor in the field of glaciology.”.
This raises serious questions about the reliability of alarmist projections of future sea-level rise predicated on these uncertain models.
Conclusion: Science vs. Sensationalism
MacKie et al.’s research offers a sober reminder that nature, not humanity, remains the dominant force shaping Antarctica’s ice dynamics. While media outlets and policymakers rush to connect every iceberg and calving event to climate change, the data tells a more nuanced story—one of natural variability and long-term cycles. It’s a story that the public deserves to hear, but one that cuts against the grain of the prevailing narrative.
As we continue to evaluate the costs and benefits of climate policies, it is imperative to ground our decisions in hard evidence rather than sensational headlines. The icebergs of Antarctica are spectacular, but they are not the smoking guns of climate change that alarmists would have us believe. Instead, they are a testament to the power of natural systems, which operate on timescales and scales far beyond our comprehension.
H/T Tom Nelson
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The recent global warming began about 12,000 years ago. Even then, gravity operated on snow and ice.
There was gravity back then?
crazy talk
Basically no trend in temperature either.
Whaddya mean ? It’s a whole degree since 2005. That’s a existential threat if we extend it out to year 2300…
Very nice.
“they are a testament to the power of natural systems, which operate on timescales and scales far beyond our comprehension”
Which is why geologists have a better grasp of this issue than almost everyone else. By comparison, ecologists/biologists freak out if something in nature changes. That’s why most of them detest forestry. I’ve been arguing with them for half a century. Unfortunately, they now dominate forestry policies here in Wokeachusetts.
It is true that a lot of marginal to bad science applications came from biologists/ecologist types and there is a lot left to correct, clarify, expand properly, or eliminate. Basic concepts like recycling lead to extremes like ecological engineering producing a hubris into some applications that should have been avoided. My B.S. was in an agricultural college where I was mostly taught the basics like statistics, physics, chemistry, geology, botany, zoology, ecology, etc. that successful agriculture, among other applied fields were based on. I did have a course on forestry before Smokey the Bear. Some biology programs have long erred with their basics and have not required enough geology which is absolutely necessary for perspective and understanding evolution.
Regardless, it will be difficult to outdo the disciplines corrupted with climate, but they are getting a lot more attention and there is a lot in the ecological literature that doesn’t get proper press or recognition in the political sphere. For example, the “demonizing” of nitrogen (the word lifted from a 2002 clarifying paper) led to the National Geographic and others, aided by scientists carried away for whatever reasons, for years claiming that the Gulf of Mexico has a dead zone of an enormous area amount implying killing everything. The modelers just caught up to the fact that the ocean is three-dimensional and that the problem is limited to some of the bottom temporarily. Besides the science these are mis- applications of statistics, but not the fault of statisticians, although there might be some argument there. We’ve all been denied due process by the system.
As I have posted before Sigma Xi, a research ‘honor’ society, has programs enabling how to get your science into policy. However, they still put out some decent articles in American Scientist, even one recently on models, but have avoided discussing climate for many years so they are de facto censors. Lots, including my students, weren’t allowed to “freak out.”
I wonder what they expected. 🤔
…. maybe a Spanish Inquisition ? 🙂
No one ever expects that
Please provide a reference to a scientific paper which states that large calving events are increasing or that large calving events have a major impact on loss of Antarctic ice. The details in the links provided don’t say what the hyperlink text indicates.
https://www.jpl.nasa.gov/news/nasa-studies-find-previously-unknown-loss-of-antarctic-ice/
https://sealevel.nasa.gov/news/266/how-ice-shelf-loss-drives-sea-level-rise/
https://www.pnas.org/doi/10.1073/pnas.1415137112
“scientific paper”
None of those references claim that large calving events are increasing. The last paper for example states that “ 95% of calving events are small and medium in scale” and for the most part is only concerned with the total amount of ice loss through calving. While the second reference is concerned with small calving events, i.e. “In a study in Antarctica last year, JPL scientist Chad Greene, Gardner and Schlegel found a surprising result. They realized that several small calving events had been overlooked.”
I’m glad you’re acknowledging the science doesn’t say large calving events are increasing due to AGW. Most alarmists get all worked up over the prospect of a melting Antarctica, sea level rise displacing billions and resulting existential threats to civilisation.
Science says the ice shelves are retreating (mainly because the grounding lines are moving inland). I’ve not seen anything about increase in size of calving. That doesn’t need to happen for Antarctica to melt – which it is doing. Charles could have done some research and written an interesting article summarizing the processes which cause ice shelves to retreat and the factors which decide how and when a calving happens. AFAIK there’s been little research into what will happen to the size of calving events. For a proper skeptical science site an interesting area to look at. Instead the article screamed that the finding of no increase in large calving disproved “alarmist” climate science. In two attempts Charles has failed to provide a link to anything remotely close to saying that increased calving size was predicted under global heating – which suggests the literature doesn’t exist. This is the quality of article you are reading and shows the site to be the sham it is.
“Science says … ” is something that should never appear in any serious discussion on any scientific subject.” Science is a process of investigation of the world we live in. It does not “say” anything. The more we study the more we learn. “Science says …” implies there is no more to be said. The reason for B is A and we’d better believe it. Wrong!
and
Is a good example of irony.
For example from here
https://www.livescience.com/antarctica-greenland-ice-loss-map-nasa.html
We have the statement
And if the ice sheets are flowing faster then the rate of calving is increased and from that one ought to predict all sizes of calving events ought to be increasing. However if that’s not the case then perhaps one needs to go back to one’s initial assumptions and recheck their validity.
Thanks Charles. Yes, if land ice was net melting as they always infer, we wouldn’t have a situation in Sydney Harbour where the average monthly mean sea level for the last 110 years is 170 mm [about 6.5 inches] LOWER than the first MSL recording in 1914.
http://www.bom.gov.au/ntc/IDO70000/IDO70000_60370_SLD.shtml
The latest monthly mean sea level [Oct. ’24] is around 4.5 inches lower.
If you click on the “plot” link on that page – it doesn’t look like those lines are going down. http://www.bom.gov.au/ntc/IDO70000/IDO70000_60370_SLI.shtml
Let’s also acknowledge there is a volcanic rift under western Antarctica larger than the African Rift Valley . The volcanic vents there get very active with each solar minimum. A few years ago I read an article that stated a team of scientists used extremely accurate laser measuring devices to discover the Earth shrank a small amount with the onset of a solar minimum resulting in an increase in volcanic and earthquake activity. .The added pressure was also the cause of the increase in vent activity. That, as one might expect, led to increasing ice melt, with the break away of a huge ice mass in 2017 the result.
“the Earth shrank a small amount with the onset of a solar minimum”
it cooled down and shrank ?
😉
Recycle time.
“When glaciers calve, alarmist have a cow.
That explains all the bellowing!”
Ah science. Refreshing.