[Tanada]

Technically for this date of the year we are at or darn near the lowest recorded sea ice for the Antarctic seas. For those who forgot Antarctic sea ice minimums are typically in March and sometimes linger into April.

https://nsidc.org/data/tools/arctic-sea-ice-chart/

You have to switch the chart to Antarctica with the tab at the top after the link loads but if you do it appears that March 3, 2017 is the record low for Antarctic Sea Ice at 2,110,000km^2 .

As of yesterday February 11, 2022 we were at 2,244,000km^2 sea ice extent.

When Larsen B ice shelf collapsed in 2002 it changed 3,250km^2 of "permanent shelf" into seasonal ice that has experienced additional shrinkage since that event 20 years ago. Now more ice shelves are at increasing risk.

Large Swath of Antarctic Ice Shelf at Risk of Collapse

A new study took a close look at what happens if climate change accelerates and continues to chip away at the floating ice shelves of Antarctica.

According to a study published on Jan. 14, 2019, in Proceedings of the National Academy of Sciences, Antarctica is melting more than six times faster than it did in the 1980s. (Jeremy Harbeck/NASA via AP)

(CN) --- The worst-case scenario is always on the horizon. It holds our attention, but even the deer caught in the headlights has a chance to act. That’s why researchers at the University of Reading in the U.K. stress the risk of a catastrophic Antarctic ice shelf collapse and sea level rise due to climate change in a study published Thursday in the journal Geophysical Research Letters.

The study evaluated the effects of global temperature increases of 1.5, 2 and 4 degrees from pre-industrial levels which will lead to greater melt and runoff and increase the risk of destabilization.

Antarctic ice shelf destabilization is likely not watercooler talk. First, let’s meet the ice shelf: a floating platform that forms around a glacier or ice sheet flows down to a coastline and to the ocean surface.

In the summer, ice at the top melts and trickles down into small air gaps, where it refreezes. But a decrease in snowfall in the last few decades means that more water pools or flows into those gaps, refreezing while changing the interior of the ice shelf.

Any signs of water on the surface spells some concern for the interior, according to the study authors.

The study set its sights on four ice shelves that could be impacted by an increase in global temperatures.

The Shackleton Ice Shelf, named after the famous Irish Antarctic explorer, extends along East Antarctica for an along-shore distance of about 240 miles and juts out around 90 miles toward the sea. It’s roughly 13,000 square miles.

The largest remaining ice shelf on the Antarctic Peninsula is the Larsen which at one point covered 33,000 square miles, but since the mid-1990s has seen several collapses and now covers roughly 26,000 square miles. A section of the shelf, Larsen C, was the focus of the study along with two other ice shelves.

The research team studied the effects of incremental warming rather than a specific gradual timescale. They used Modèle Atmosphérique Régional, an atmosphere model designed for climate research.

There are multiple variables at play when it comes to analyzing the melt and accumulation of snow on the surface of an ice shelf. This surface mass balance is decreased due to climate change because there is more meltwater, which then runs off the ice shelves. Once this process runs away, ice shelves undergo what’s called hydrofracturing, when they crack and disintegrate.

As much as 34% of all Antarctic ice shelves would be at risk of destabilization under 4 degrees of warming. As much as 67% of the ice shelf area in the Antarctic Peninsula in the western end of the continent would be at risk of collapse.

"Ice shelves are important buffers preventing glaciers on land from flowing freely into the ocean and contributing to sea level rise,” said research scientist Ella Gilbert with University of Reading's Department of Meteorology, in a statement. “When they collapse, it's like a giant cork being removed from a bottle, allowing unimaginable amounts of water from glaciers to pour into the sea.”

In an email Gilbert said, “I hope that the average reader takes away that the more we do to limit warming, the lower the risk of ice shelf collapse and therefore sea level rise will be.”

LINK

[Tanada]

Link to full article at bottom of quote. This is a scientific study of the summer 2019 rapid drainage event on the Amery Ice Shelf.

Rapid Formation of an Ice Doline on Amery Ice Shelf, East Antarctica
Abstract

Surface meltwater accumulating on Antarctic ice shelves can drive fractures through to the ocean and potentially cause their collapse, leading to increased ice discharge from the continent. Implications of increasing surface melt for future ice shelf stability are inadequately understood. The southern Amery Ice Shelf has an extensive surface hydrological system, and we present data from satellite imagery and ICESat-2 showing a rapid surface disruption there in winter 2019, covering ∼60 km2. We interpret this as an ice-covered lake draining through the ice shelf, forming an ice doline with a central depression reaching 80 m depth amidst over 36 m uplift. Flexural rebound modeling suggests 0.75 km3 of water was lost. We observed transient refilling of the doline the following summer with rapid incision of a narrow meltwater channel (20 m wide and 6 m deep). This study demonstrates how high-resolution geodetic measurements can explore critical fine-scale ice shelf processes.
Plain Language Summary

Surface melting over Antarctica's floating ice shelves is predicted to increase significantly during coming decades, but the implications for their stability are unknown. The Antarctic Peninsula has already seen meltwater driven ice shelf collapses. We are still learning how meltwater forms, flows and alters the surface, and that rapid water-driven changes are not limited to summer. We present high-resolution satellite data (imagery and altimetry) showing an abrupt change on East Antarctica's Amery Ice Shelf in June 2019 (midwinter). Meltwater stored in a deep, ice-covered lake drained through to the ocean below, leaving a deep, uneven 11 km2 depression of fractured ice (a “doline”) in the ice shelf surface. The reduced load on the floating ice shelf resulted in flexure, with over 36 m of uplift centered on the former lake. Simple flexure modeling showed that this corresponds to about 0.75 km3 of water being lost to the ocean. ICESat-2 observations in summer 2020 profiled a new narrow channel inside the doline as meltwater started refilling it from a new lake created by the flexure. ICESat-2's capacity to observe surface processes at small spatial scales greatly improves our ability to model them, ultimately improving the accuracy of our projections.

LINK

[Tanada]

According to

Antarctic sea ice extent reached a new record low of 1.965 million km2 on 23 February 2022. This extent is approximately 32% below climatological values and might indicate a transition to new, more extreme, annual fluctuations.

Pay Per View Article

However the chart on NSIDC You have to click the Antarctica button at upper left
the actual minimum was set three days later on 2/25/2022 with a new record low of 1,924,000 km^2 extent.

Both easily beat the 2017 record so either way we have a new all time low for Antarctic Sea Ice.

[Newfie]

Tanada,

Thanks for keeping track.

[Doly]

Both easily beat the 2017 record so either way we have a new all time low for Antarctic Sea Ice.

Antarctic sea ice is the one to really watch, rather than the Arctic. This is because variations in ice cover for the Arctic are within the boundaries of our current geological era, including previous interglacial periods. But a significant reduction in Antarctic sea ice could indicate moving towards the climate pattern of a time when there weren't any humans on Earth.

[Tanada]

A previously stable ice shelf, the size of New York City, collapses in Antarctica

The Associated Press March 25, 20222:42 PM ET
An ice shelf the size of New York City has collapsed in East Antarctica, an area long thought to be stable and not hit much by climate change, concerned scientists said Friday.

The collapse, captured by satellite images, marked the first time in human history that the frigid region had an ice shelf collapse. It happened at the beginning of a freakish warm spell last week when temperatures soared more than 70 degrees warmer than normal in some spots of East Antarctica. Satellite photos show the area had been shrinking rapidly the last couple of years, and now scientists say they wonder if they have been overestimating East Antarctica's stability and resistance to global warming that has been melting ice rapidly on the smaller western side and the vulnerable peninsula.

The ice shelf, about 460 square miles wide (1,200 square kilometers) holding in the Conger and Glenzer glaciers from the warmer water, collapsed between March 14 and 16, said ice scientist Catherine Walker of the Woods Hole Oceanographic Institute. She said scientists have never seen this happen in this part of the continent and that makes it worrisome.

"The Glenzer Conger ice shelf presumably had been there for thousands of years and it's not ever going to be there again," said University of Minnesota ice scientist Peter Neff.

The issue isn't the amount of ice lost in this collapse, Neff and Walker said. It's negligible. But it's more about the where it happened.

Neff said he worries that previous assumptions about East Antarctica's stability may not be so right. And that's important because the water frozen in East Antarctica if it melted — and that's a millennia-long process if not longer — would raise seas across the globe more than 160 feet (50 meters). It's more than five times the ice in the more vulnerable West Antarctic Ice Sheet, where scientists have concentrated much of their research.

Scientists had been seeing the ice shelf shrink a bit since the 1970s, Neff said. Then in 2020, the shelf's ice loss sped up to losing about half of itself every month or so, Walker said.

"We probably are seeing the result of a lot of long time increased ocean warming there," Walker said. "it's just been melting and melting."

And then last week's warming "probably is something like, you know, the last straw on the camel's back."

LINK

[Newfie]

Ugh!

[theluckycountry]

Thanks for taking the effort to post up this thread Tanaka, I will spend a couple of hours going over the data and looking for updates. For years I listened to the Radio Ecoshock podcasts, but sort of lost interest when Trump was elected because he dragged too much politics onto the show. He does interview all the experts there, no doubt about it.

[Tanada]

Click link to go to NASA graph of Antarctic ice mass loss since 2002.

GRAPH

[Doly]

For years I listened to the Radio Ecoshock podcasts, but sort of lost interest when Trump was elected because he dragged too much politics onto the show.

That's the thing with climate change. It shouldn't be political, but it has become politicised, and that can't be avoided.

[theluckycountry]

For years I listened to the Radio Ecoshock podcasts, but sort of lost interest when Trump was elected because he dragged too much politics onto the show.

That's the thing with climate change. It shouldn't be political, but it has become politicized, and that can't be avoided.

So true Doly, I can understand why the science itself is screwed over by politicians, but to have an unqualified presenter interject his personal political opinions into interviews with leading scientists was just wrong I thought.

[theluckycountry]

Click link to go to NASA graph of Antarctic ice mass loss since 2002.

GRAPH

That's a very linear chart isn't it. No guarantee it will stay that way of course.

[Tanada]

Click link to go to NASA graph of Antarctic ice mass loss since 2002.

GRAPH

That's a very linear chart isn't it. No guarantee it will stay that way of course.

What stands out to me is the graph starts in 2002 and the change is very minor for two or three years, then it accelerates for the last 17 years despite the fact that we have been in a low solar cycle for most of the 21st century. You can look back at solar cycles starting in 1700 and there is a clear 100 year patter superimposed on the 11 year and 66 year cycles. The first two decades each century have unusually low sunspot cycles, which is supposed to mean a cooling trend. Despite that cooling trend we have been losing more ice at both poles since about 2005 which looks ever more like we passed a climate tipping point to me. Here we are 17 years later and global GHG levels are increasing at a continuing faster rate compared to 2002 and all the years earlier.

I first really learned about CO2 emission back in 1988 when my local region went through a very severe drought. That was when Dr. James Hansen NASA scientist testified before congress about the fact that we had just passed the 350 ppmv mark for CO2 and that the last time climate had experienced those levels was before the Greenland Ice Sheet formed about 2.8 million years ago. Right now we are over 420 ppmv meaning in 35 years we have added an additional 70 million ppmv CO2 and our emission rates are still climbing. It is clear now humanity is not going to turn away from fossil fuels voluntarily and it is also clear Peak Oil will not do the trick either because we will simply make synthetic petroleum products from Natural Gas and Coal and Extra Heavy Oil from Venezuela and other places rather than change our lifestyle.

Adapt, or see your extended family consumed in the chaos that results from climate flipping into the hothouse mode.

[Doly]

It is clear now humanity is not going to turn away from fossil fuels voluntarily and it is also clear Peak Oil will not do the trick either because we will simply make synthetic petroleum products from Natural Gas and Coal and Extra Heavy Oil from Venezuela and other places rather than change our lifestyle.

Natural gas is also depleting, the peak is expected to be a bit later than oil but not so much later that it can be ignored. As for using coal, it's possible but there are no signs that it's being planned in any sort of extensive scale, and it's an expensive process, so it's likely to be done in a limited scale if it gets done at all. When it comes to extra heavy oil, we are doing it already and it's included in peak calculations.

[Newfie]

Don’t look down.

And then in 2021, a study showed the Thwaites Ice Shelf, which helps to stabilize the glacier and hold the ice back from flowing freely into the ocean, could shatter within five years.
"From the satellite data, we're seeing these big fractures spreading across the ice shelf surface, essentially weakening the fabric of the ice; kind of a bit like a windscreen crack," Peter Davis, an oceanographer with the British Antarctic Survey, told CNN in 2021. "It's slowly spreading across the ice shelf and eventually it's going to fracture into lots of different pieces."
Monday's findings, which suggest the Thwaites is capable of receding at a much faster pace than recently thought, were documented on a 20-hour mission in extreme conditions that mapped an underwater area the size of Houston, according to a news release.

https://www.cnn.com/2022/09/05/world/th ... index.html

[rangerone314]

Adapt, or see your extended family consumed in the chaos that results from climate flipping into the hothouse mode.

I wonder about buying some land in Iceland that will be tropical beachfront eventually..

[C8]

The Real Inconvenient Truth: Arctic Sea Ice Has Grown Since 2012

Global warming paused, polar bears thriving, more coral on the Great Barrier Reef than you can shake a stick at – it’s been a difficult gig for climate alarmists of late. But there is always the melting Arctic ice, and the prospect of the Greenland ice sheet slipping off its perch and ending up in your front room. Alas, even that old standby is looking shaky, with evidence gathering that the ice is no longer melting as fast as in the recent past. On August 16th, summer sea ice in the Arctic was at its third highest extent since 2007.

According to the U.S.-based National Snow and Ice Data Centre (NSIDC), the northern sea route along Eurasia “may not become ice free” this year for the first time since 2007. Preliminary estimates by NSIDC suggest a 30% chance that sea ice will cover five million square kilometres, something that has not happened for eight years.

[Outcast_Searcher]

Adapt, or see your extended family consumed in the chaos that results from climate flipping into the hothouse mode.

I wonder about buying some land in Iceland that will be tropical beachfront eventually..

But depending on the lay of the land, SLR, the impact of rising temps, etc, by the time it's nice beach front property (if that pans out in a good way instead of a bad way, at meh odds) -- you're likely much better off investing in stocks and hoping the wheels don't come off for the masses before you get too old for it to matter much.

I'm 63 and living in a relatively safe area (so far) re threats from desertification, too hot to survive, SLR, too many fires, earthquakes, hurricanes, blizzards, etc. And even then, I think it might be an interesting race re what is most troublesome / annoying as I age, re quality of life, if I make it well into my 80's.

I have to feel REAL bad for my nieces and nephews in their 30's, and especially their kids, re what AGW will do to their lives.

And maybe humanity will mostly scrape by for many decades employing all sorts of "Star Trek" like technology to remove lots of CO2. One can only imagine the tax rates required to make such things happen.

It's so ironic. The way I imagined the world evolving when I was in college 40+ years ago and getting educated enough to begin to have a clue to use for extrapolation guesses, things are MUCH better than what I imagined, re computers / technology and their impacts, but MUCH worse re the net degradation to the planet and population growth despite ALL the evidence for what a problem that is.

[Tanada]

COP27 video conference on Antarctic ice shelf vulnerability and collapse risks.
Video

[Plantagenet]

Antarctic Sea Ice is at a record low right now and its looking like it will hit its all time record low later in this melt season

antarctic sea ice

Ring a bell --- thats a big step towards more global warming.



cheers!