The calving of the 1.1 trillon ton ice berg (2x amount of water used in the US each year) marks the end of a decades long splintering, first seen by satellites in the 1960s.
1. What's next? It will drift north along the coast of the Antarctic Peninsula, then northeast into the south Atlantic Ocean. Likely no threat to ships navigating the area. Can take months to splinter apart.
2. Is this climate change? Calving is a natural process and Antarctica is not breaking apart, but climate change can't be ruled out.
3. What does it mean for Antarctica? Not much on its own, but could be a signal that other major changes are on the way. Paying attention to the Thwaites Glacier, which could raise sea levels 10 feet if it collapses.
4. Will it make the oceans rise? barely (0.1 mm)
5. Politics: The calving was barely noticed on Capitol Hill, which is distracted by a bitter health care debate, federal budget bills, and the controversy surrounding President Trump and Russia.
P.S.: Read the full article -- it's worth it and has interesting illustrations showing the scale of the event.
>"2. Is this climate change? Calving is a natural process and Antarctica is not breaking apart, but climate change can't be ruled out."
"Climate change" doesn't make specific enough predictions about this type of stuff to ever be ruled out, people could just keep coming up with ideas about X indefinitely:
Climate Change -> X -> Larsen C rift
A more accurate way to put it is that, up until now, all proposed ideas for X have been ruled out (I am basing this all on the comments from the MIDAS team about the ice thickening, etc).
At the same time I find it totally implausible that there is zero link between this event (or anything else that happens on earth) and the climate. So "no link" should be taken as shorthand "any influence due to climate change is a negligible factor".
Also, it is clear to me from reading the news and comments about this event that many people really, really want this to be linked to climate change. It is to the point that cognitive dissonance ensues when it is pointed out the experts are in disagreement with them. That is unhealthy.
>> Also, it is clear to me from reading the news and comments about this event that many people really, really want this to be linked to climate change. It is to the point that cognitive dissonance ensues when it is pointed out the experts are in disagreement with them. That is unhealthy.
I think it's healthy. The people who experience cognitive dissonance are so personally invested in their belief that they are no longer able to see things objectively. That's not a good place to be in any case.
Go through my comment history for this topic, you will find some of the most bizarre reasons proposed for why the MIDAS team was being quoted as saying this is probably natural and not anything ominous.
Just go through this thread. Almost every poster knows there is some ominous global warming stuff going on here, despite being told otherwise by the experts and being totally ignorant on the topic.
> "Climate change" doesn't make specific enough predictions about this type...
Actually it does. In a warming world more frequent calving events are expectable. This part of Antarctica shows quite some positive temperature anomalies. So, asking whether Larsen C would be still intact today without Climate Change the answer is certainly yes.
As I said a month ago when this coverage started, it is very strange how there are so many people (in the media and internet posters) who are so sure about that, when the actual people studying it claim otherwise: https://news.ycombinator.com/item?id=14577296
>“Although this is a natural event, and we’re not aware of any link to human-induced climate change, this puts the ice shelf in a very vulnerable position. This is the furthest back that the ice front has been in recorded history. We’re going to be watching very carefully for signs that the rest of the shelf is becoming unstable.”
http://www.projectmidas.org/blog/calving/
>'Andrew Shepherd, professor of Earth Observation at the University of Leeds, agreed. “Everyone loves a good iceberg, and this one is a corker,” he said. “But despite keeping us waiting for so long, I’m pretty sure that Antarctica won’t be shedding a tear when it’s gone because the continent loses plenty of its ice this way each year, and so it’s really just business as usual!”https://www.theguardian.com/world/2017/jul/12/giant-antarcti...
>"And while climate change is accepted to have played a role in the wholesale disintegration of the Larsen A and Larsen B ice shelves, Luckman emphasised that there is no evidence that the calving of the giant iceberg is linked to such processes." https://www.theguardian.com/world/2017/jul/12/giant-antarcti...
Look, I did not answer the irrelevant question whether Larsen C calved because of Climate Change. Attributing single events in remote areas is hard. That's why I answered a different question, the key words are 'today' and 'more frequently', please read the comment carefully again.
I think if you compare historical rates of iceberg calving to current rates of iceberg calving, you should be able to find some significant quantifiable difference.
Although ultimately the important thing is the influence on flow rates of land-based ice.
Of course there's a link between this event and the climate. Clearly. If Antarctica weren't cold, there would be no ice shelf to begin with.
The salient point is that this specific event would have seemingly happened with or without our currently-changing climate. As the iceberg that the shelf extends from flows out toward the ocean, the shelf grows until it reaches a point where forces acting on the floating mass of ice induce part of it to calve away from the rest of the shelf.
> Calving is a natural process and Antarctica is not breaking apart, but climate change can't be ruled out.
This is science's inherent weakness in the public eye: the pundits on both sides will make conclusive statements based on little data; the scientists, with all the data we have, only speak in chances, odds, and percentages.
It's not their fault, it's the correct way to speak. But both sides will spin this to suit their agenda, for better or worse, and continue to muddy the waters.
Where do they get that? The melting of already-floating icebergs has zero net effect on sea lever or (liquid) water volume. It would take a huge amount of added water to make even a .1mm effect worldwide.
It is the melting of the ice on above the water surface minus the difference in volume of the ice below the surface and the water it would become. Someone else mentioned that if the entire iceberg were melted it would cover California with 4.5in of water. If you divide that by the ratio of the ocean area to the area of California you get 0.13mm. I'm not sure how much is above the water vs below the surface but it seems like a reasonable thing for them to estimate.
The article explains that an iceberg of this size would add 3 mm to sea levels if it had not already been floating in the ocean. I'm curious, too, about the 0.1 mm.
I think this advice which is in all reports of this event is quite tenuous:
"The calving of icebergs is a natural process. ... as news of the calving spread, many researchers were careful to note that they were not chalking it up to global warming."
The falling of trees is a natural process but when they fall in a storm we don't often say to not chalk it up to the storm.
People tend to blame the last straw for breaking the camel's back, but each individual straw shares equal responsibility.
When a tree falls, the rain that loosened the soil around the roots, the wind that pushed upon the end of the trunk-lever, and the beetle that damaged the bark such that the tree became less flexible are all responsible.
When it comes to icebergs calving from glaciers, warming is a contributing factor, but so is a snowfall upon the glacier further up the slope. Ice above pushes ice below away from the support of land, and like many crystalline minerals, water-ice has far less strength under tension than it has under compression.
We don't have long enough experience with ice shelves to know what their baseline behavior is. And the effects of global warming in the Antarctic are less straightforward than in the Arctic. For example, winter sea ice extent there is increasing, not decreasing.
As I understand it - the sea ice extent is a quite different matter being thin and regenerating yearly. These lost iceshelves (including Larsen B in 2001) were hundreds of meters thick.
I wonder what age these shelves were and what a sustainable rate of such events would be. Without seeing such information I dont trust general statements on the events meaning.
As another massive iceshelf breaks off - it really looks like an event which we could connect with more for these environmentally crucial times.
I cited sea ice as an example of counterintuitive effects of climate change.
These shelves move fairly rapidly, and will calve with or without global warming. The Ross Ice Shelf, for example, moves northwards at about 1 km/year.
TFA doesn't offer dimensions, but it does say the total area of the berg is 2,200 mi^2, which if square (overestimation given the picture) would give a depth of about 75km to this calving.
The grandparent says that the ice shelf moves into the ocean at about 1km/yr.
This specific calving has been going on in stages since at least the 1960's.
Within the order of magnitudes of estimation, that lines up entirely with natural process that has been going on at roughly the same rate since the 60's. Climate change hasn't had a measurable effect so far, based on this limited data point.
I think the scientist's quoted cautious skepticism is entirely appropriate.
I just see a hastily laid out argument. The 1km/yr we have no idea what it really means, does that relate to previous centuries? or is it just the rate observed during recent times? (while global warming has already been detected)
The maps show the very location of these events, raised by several degrees C since 1950. The rate of this event is quite certainly strongly affected by local temperature, which is known to be elevated due to global warming. So the event has quite certainly been strongly affected by global warming.
I can conclude this very confidently because global warming is already a given for me. Only when we doubt global warming has raised the temperature of the location of these calving events does it make any sense to say, "this could be happening naturally"
However fast this could happen naturally - it is happening faster due to global warming.
That's motivated reasoning. I'm not denying climate change. I'm just saying we should be very careful to not ascribe anything and everything to climate change unless there is clear evidence.
The thing is... If we wanted to not in interfere, and let the natural process do its thing, we'd be looking at the end of the inter-glacial period in the next 1000 years. After that we'd see glaciation starting to cover a lot of the northern hemisphere. Sea levels would start to drop - ultimately several hundred feet, exposing the continental shelf everywhere. All our coastal cities would be inland.
Some have said that even all the CO2 we can produce won't be enough to stop the natural cycle. I wonder if it will actually speed it up a little bit. Something triggers the end of the inter-glacial and clearly we are not there yet. Therefore, I conclude that the planet was never at the steady state the climate alarmists pretend it was before humans interfered.
Yes, they do pretend. Sea levels have been rising for 10000 years and they act like that trend stopped and the rise from here on out is all caused by human activity.
BTW: Was it ever considered to offer desalinated water in California at a higher rate, so people who wish to do so can waste it on their lawn or proper showers without the shaming?
While desalinated is technically doable, is it scalable yet so that it could even be offered? I honestly don't know much about it but was under the impression it simply wouldn't work to provide California water because it's not yet able to scale enough to meet a large enough fraction of the need.
I could certainly be wrong though. I couldn't find much info googling.
Naively, the energy cost of towing should go as the 2/3 power of the mass of the iceberg, whereas the energy cost of desalination is linear. So bigger is better!
Of course, it's a million times bigger than the biggest iceberg ever towed, so I guess there is some technical risk. But where's your can-do attitude?
It's funny to me, because at this point, there's glaring scientific evidence to demonstrate not-trivially-reversible anthropogenic climate change, and we're sort of at that same point where we were with leaded gasoline, where it's not about whistle-blowers anymore, but there's still an intractable scientific payola to plant the seed of doubt in any conversation.
Action is required at this point, regardless of transnational economic inertia.
What does it take to root out scientific provocateurs, and shut them up?
I agree that there is human caused changing of the global climate due to emissions from fossil fuels, among other things. With that said, did you read the article?
> The calving of icebergs is a natural process. While climate change is affecting Antarctica in a variety of ways, this week's event does not signal that the region is entering a new state. That is happening in the Arctic, which has already been dramatically reshaped by human-caused global warming, according to National Oceanic and Atmospheric Administration researchers. Scientists do not believe Antarctica is in a precipitous state of warming right now. Yesterday, as news of the calving spread, many researchers were careful to note that they were not chalking it up to global warming.
Climate change is an important issue to be sure, but this seems unrelated.
URGENT LOAN HELP @ 2% INTEREST RATE with Victoriafinancier@outlook.com
I was stuck in a financial situation and i needed to refinance and pay my bills for my son's medication and buy a home. I tried seeking for a loans from various loan firms both private and corporate but never with success, and most banks declined my credit. But as God would have it, i was introduced to VICTORIA LAWSON Trust Loan Firm ( victoriafinancier@outlook.com ) with 2% interest by a friend, and i got a loan amount within 2 weeks because i was not always online to responds to her mails. Today am a business owner and my kids are doing well... so i want to advice any one in need of a loan to quickly contact her via email on victoriafinancier@outlook.com. I own Victoria every day appreciation for all she has done in my life. Her service is strong, big and reliable.
Full Name:_________
Address:_________
Tell:_________
loan amount:_________
Loan duration:_________
Country:_________
Purpose of loan:_________
Monthly Income:__________
Occupation__________
Next of kin:_________
*Email :_________
Contact Her today { victoriafinancier@outlook.com } for quick and financial assistance
Good news about the bedrock holding the iceberg in place.
As a casual earth science enthusiast, I believe this means that the melt-water will stay proximal, and will encourage accelerated freezing on the coast, somewhat "repairing" the damage.
When it breaks up/drifts away, the coast will be subject to normal freezing patterns from the briny water.
I think you may have misunderstood - it is the Larsen C shelf that is held in place, not the iceberg that it calved:
An iceberg the size of Delaware is now in motion. If it follows the path of previous icebergs from the Larsen Ice Shelf, it will drift north along the coast of the Antarctic Peninsula before heading northeast into the south Atlantic Ocean, according to NASA.
it seems to me that the way scientists address the question of "is this global warming?" is wrong-headed, even though it's not literally wrong.
We deal with this frequently in medicine. There are lots of questions that the non-expert doesn't know how to ask, or asks clumsily. When patients ask "doctor: does this medication have any risks?" The literal answer is "yes; dozens of side effects are possible, ranging from mild to life-threatening".
But that answer is so accurate that it's useless. What almost all patients really want is "help me understand the most common side effects, and tell me what to watch out for regrading rare-but-serious side effects".
With respect to global warming, we don't really care whether this event can be tied back to antropegenic climate change in a linear way. What we really are asking is "should we be taking climate change seriously?". And the answer is an emphatic "hell yes".
This is an opportunity for people to focus on climate issues. I worry that HN will think I'm a paternalist jerk, but scientists shouldn't get bogged down in the literal answer to the literal question in this case.
My best answer would be "climate change is real, accelerating (meaning getting worse every day we continue to consume more fossil fuels), and the biggest threat we have to face as a species".
56 comments
[ 3.2 ms ] story [ 111 ms ] threadThe calving of the 1.1 trillon ton ice berg (2x amount of water used in the US each year) marks the end of a decades long splintering, first seen by satellites in the 1960s.
1. What's next? It will drift north along the coast of the Antarctic Peninsula, then northeast into the south Atlantic Ocean. Likely no threat to ships navigating the area. Can take months to splinter apart.
2. Is this climate change? Calving is a natural process and Antarctica is not breaking apart, but climate change can't be ruled out.
3. What does it mean for Antarctica? Not much on its own, but could be a signal that other major changes are on the way. Paying attention to the Thwaites Glacier, which could raise sea levels 10 feet if it collapses.
4. Will it make the oceans rise? barely (0.1 mm)
5. Politics: The calving was barely noticed on Capitol Hill, which is distracted by a bitter health care debate, federal budget bills, and the controversy surrounding President Trump and Russia.
P.S.: Read the full article -- it's worth it and has interesting illustrations showing the scale of the event.
"Climate change" doesn't make specific enough predictions about this type of stuff to ever be ruled out, people could just keep coming up with ideas about X indefinitely:
A more accurate way to put it is that, up until now, all proposed ideas for X have been ruled out (I am basing this all on the comments from the MIDAS team about the ice thickening, etc).At the same time I find it totally implausible that there is zero link between this event (or anything else that happens on earth) and the climate. So "no link" should be taken as shorthand "any influence due to climate change is a negligible factor".
Also, it is clear to me from reading the news and comments about this event that many people really, really want this to be linked to climate change. It is to the point that cognitive dissonance ensues when it is pointed out the experts are in disagreement with them. That is unhealthy.
I think it's healthy. The people who experience cognitive dissonance are so personally invested in their belief that they are no longer able to see things objectively. That's not a good place to be in any case.
Actually it does. In a warming world more frequent calving events are expectable. This part of Antarctica shows quite some positive temperature anomalies. So, asking whether Larsen C would be still intact today without Climate Change the answer is certainly yes.
>“Although this is a natural event, and we’re not aware of any link to human-induced climate change, this puts the ice shelf in a very vulnerable position. This is the furthest back that the ice front has been in recorded history. We’re going to be watching very carefully for signs that the rest of the shelf is becoming unstable.” http://www.projectmidas.org/blog/calving/
>'Andrew Shepherd, professor of Earth Observation at the University of Leeds, agreed. “Everyone loves a good iceberg, and this one is a corker,” he said. “But despite keeping us waiting for so long, I’m pretty sure that Antarctica won’t be shedding a tear when it’s gone because the continent loses plenty of its ice this way each year, and so it’s really just business as usual!”https://www.theguardian.com/world/2017/jul/12/giant-antarcti...
>"And while climate change is accepted to have played a role in the wholesale disintegration of the Larsen A and Larsen B ice shelves, Luckman emphasised that there is no evidence that the calving of the giant iceberg is linked to such processes." https://www.theguardian.com/world/2017/jul/12/giant-antarcti...
I think if you compare historical rates of iceberg calving to current rates of iceberg calving, you should be able to find some significant quantifiable difference.
Although ultimately the important thing is the influence on flow rates of land-based ice.
The salient point is that this specific event would have seemingly happened with or without our currently-changing climate. As the iceberg that the shelf extends from flows out toward the ocean, the shelf grows until it reaches a point where forces acting on the floating mass of ice induce part of it to calve away from the rest of the shelf.
This is science's inherent weakness in the public eye: the pundits on both sides will make conclusive statements based on little data; the scientists, with all the data we have, only speak in chances, odds, and percentages.
It's not their fault, it's the correct way to speak. But both sides will spin this to suit their agenda, for better or worse, and continue to muddy the waters.
EDIT: Apparently the 0.1 mm change is due to the difference in salinity. https://phys.org/news/2005-08-ice-sea.html
This won't hold true when melting a _freshwater_ ice in _salty_ water, but I too doubt the change will be anywhere near 0.1mm
"The calving of icebergs is a natural process. ... as news of the calving spread, many researchers were careful to note that they were not chalking it up to global warming."
The falling of trees is a natural process but when they fall in a storm we don't often say to not chalk it up to the storm.
When a tree falls, the rain that loosened the soil around the roots, the wind that pushed upon the end of the trunk-lever, and the beetle that damaged the bark such that the tree became less flexible are all responsible.
When it comes to icebergs calving from glaciers, warming is a contributing factor, but so is a snowfall upon the glacier further up the slope. Ice above pushes ice below away from the support of land, and like many crystalline minerals, water-ice has far less strength under tension than it has under compression.
I wonder what age these shelves were and what a sustainable rate of such events would be. Without seeing such information I dont trust general statements on the events meaning.
As another massive iceshelf breaks off - it really looks like an event which we could connect with more for these environmentally crucial times.
These shelves move fairly rapidly, and will calve with or without global warming. The Ross Ice Shelf, for example, moves northwards at about 1 km/year.
If we are with the consensus on climate change, there is very little doubt this event is affected by it. It occurred in most warmed area of this map:
http://www.realclimate.org/wp-content/uploads/ODonnell1.png
From here:
http://www.realclimate.org/index.php/archives/2010/12/a-brie...
I dont see any sense in excluding these quite rare events from the confidence of climate change, unless we are not confident in climate change.
The grandparent says that the ice shelf moves into the ocean at about 1km/yr.
This specific calving has been going on in stages since at least the 1960's.
Within the order of magnitudes of estimation, that lines up entirely with natural process that has been going on at roughly the same rate since the 60's. Climate change hasn't had a measurable effect so far, based on this limited data point.
I think the scientist's quoted cautious skepticism is entirely appropriate.
The maps show the very location of these events, raised by several degrees C since 1950. The rate of this event is quite certainly strongly affected by local temperature, which is known to be elevated due to global warming. So the event has quite certainly been strongly affected by global warming.
I can conclude this very confidently because global warming is already a given for me. Only when we doubt global warming has raised the temperature of the location of these calving events does it make any sense to say, "this could be happening naturally"
However fast this could happen naturally - it is happening faster due to global warming.
Some have said that even all the CO2 we can produce won't be enough to stop the natural cycle. I wonder if it will actually speed it up a little bit. Something triggers the end of the inter-glacial and clearly we are not there yet. Therefore, I conclude that the planet was never at the steady state the climate alarmists pretend it was before humans interfered.
"Some have said" -- Stop. Just stop.
If you can't cite, you aren't worth debating.
https://www.theguardian.com/environment/2017/may/05/could-to...
I could certainly be wrong though. I couldn't find much info googling.
The Gulf countries offer desalinated water at city scale, but it's not cheap enough for irrigation.
Naively, the energy cost of towing should go as the 2/3 power of the mass of the iceberg, whereas the energy cost of desalination is linear. So bigger is better!
Of course, it's a million times bigger than the biggest iceberg ever towed, so I guess there is some technical risk. But where's your can-do attitude?
Action is required at this point, regardless of transnational economic inertia.
What does it take to root out scientific provocateurs, and shut them up?
> The calving of icebergs is a natural process. While climate change is affecting Antarctica in a variety of ways, this week's event does not signal that the region is entering a new state. That is happening in the Arctic, which has already been dramatically reshaped by human-caused global warming, according to National Oceanic and Atmospheric Administration researchers. Scientists do not believe Antarctica is in a precipitous state of warming right now. Yesterday, as news of the calving spread, many researchers were careful to note that they were not chalking it up to global warming.
Climate change is an important issue to be sure, but this seems unrelated.
Address:_________
Tell:_________
loan amount:_________
Loan duration:_________
Country:_________
Purpose of loan:_________
Monthly Income:__________
Occupation__________
Next of kin:_________
*Email :_________
Contact Her today { victoriafinancier@outlook.com } for quick and financial assistance
As a casual earth science enthusiast, I believe this means that the melt-water will stay proximal, and will encourage accelerated freezing on the coast, somewhat "repairing" the damage.
When it breaks up/drifts away, the coast will be subject to normal freezing patterns from the briny water.
An iceberg the size of Delaware is now in motion. If it follows the path of previous icebergs from the Larsen Ice Shelf, it will drift north along the coast of the Antarctic Peninsula before heading northeast into the south Atlantic Ocean, according to NASA.
We deal with this frequently in medicine. There are lots of questions that the non-expert doesn't know how to ask, or asks clumsily. When patients ask "doctor: does this medication have any risks?" The literal answer is "yes; dozens of side effects are possible, ranging from mild to life-threatening".
But that answer is so accurate that it's useless. What almost all patients really want is "help me understand the most common side effects, and tell me what to watch out for regrading rare-but-serious side effects".
With respect to global warming, we don't really care whether this event can be tied back to antropegenic climate change in a linear way. What we really are asking is "should we be taking climate change seriously?". And the answer is an emphatic "hell yes".
This is an opportunity for people to focus on climate issues. I worry that HN will think I'm a paternalist jerk, but scientists shouldn't get bogged down in the literal answer to the literal question in this case.
My best answer would be "climate change is real, accelerating (meaning getting worse every day we continue to consume more fossil fuels), and the biggest threat we have to face as a species".