Antarctica: Larsen C breakoff could have 'dire consequences'

[nitpicker]

http://www.dw.com/en/antarctica-larsen-c-breakoff-could-have-dire-consequences/a-39489181

Antarctica: Larsen C breakoff could have 'dire consequences'

(snip)
Larsen C is a major ice shelf located on the Antarctic Peninsula, extending out over the ocean - a large fracture across the ice sheet is poised release an iceberg the size of the state of the US state of Delaware (a quarter the size of Wales, or twice the size of Luxembourg). Consequences could be dramatic - as Antarctica melts, scientists fear it will soon desintegrate.

Adding to this, Trump's withdrawal from the Paris Agreement and cuts for scientific research in the US might hinder future research around changes.

DW speaks with professor of thermal sciences John Abraham to find out what is the importance of Larsen C and how the scientific community is coping with Trump's moves.

DW: What are the consequences of this huge portion of ice breaking off into the ocean?

John Abraham: Frankly, the consequences could be dire - but we don't know exactly. These ice shelves stabilize the ice sheets - but when they break off, they can create an unstable situation. What scientists really want to know is what will happen after this portion of the ice shelf breaks off.

When is it expected to break off and how will we know?

Scientists know it's going to because we're watching it in real time. A large crack - sometimes called a "rift" - has formed, and we can watch it progress day by day, week by week. The rift has nearly cracked the portion of the ice shelf through.

It's not the first time this has happened there. The Larsen A and Larsen B ice shelves have seen breakoffs, too.

That's exactly right. The Larsen B famously collapsed in just a matter of a few weeks after a portion of its ice shelf broke off into the ocean. Much of the upstream ice then subsequently collapsed. So we're hoping that that doesn't happen with Larsen C, which is much bigger. But we're fearful it may.

Since when have these ice shelves been breaking?

Larsen A, one of the smaller ice shelves, disintegrated in 1995. It was followed by the Larsen B, which dramatically disintegrated in 2002 over a matter of a few weeks. And now we have Larsen C, which is disintegrating over 2016 and 2017.

In terms of the lifetime of these shelves, this is a pretty rapid succession of collapses. Are these natural occurrences, or as a result of human activity?

That's a subjective debate - but many scientists think that it's because of human warming of the planet. As humans put out more greenhouse gases that trap heat, this results in both the air and the ocean waters warming. So these ice shelves experience heating from both above and below - and we know that impacts the health of the ice shelf. The question is, would this have collapsed naturally? Or was human warming the straw that broke the camel's back, so to speak? And many scientists believe that this is a sign of what's to come. And that's what got us really concerned.

And so, what are the consequences of all that ice going into the ocean?

Scientists know the ocean levels are rising at a few millimeters per year, right now. But we are seeing that sea level rise is accelerating - it's rising faster and faster. If you ask oceanographers what the oceans will be like by 2100, the general view is that it's going to be 1 meter [3 feet and 3 inches] higher than it is today.

[longship]

1. I think one meter rise by 2100 is an overly cautious estimate.

But that's how science is, with good reason. Don't extrapolate beyond the data!

What the science does say about these ice shelves is that they are bolsters to the inland ice sheets. The fact that in the midst of Southern Hemisphere winter the Larsen C is collapsing is a very worrisome thing.

And remember the albedo of ice versus open sea. Ice reflects solar energy; open sea absorbs it. We are seeing the same thing in the Arctic. And this isn't just about polar bears and Adele penguins. This is about unleashing a positive feedback mechanism on our planet.

Larsen C is the size of the state of Delaware!!! And it is going to collapse in the midst of Southern Hemisphere winter!

But global climate change is a Chinese hoax!!!!

Right!

[JayhawkSD]

2. Did you notice that he did not actually answer the question?

And so, what are the consequences of all that ice going into the ocean?

Scientists know the ocean levels are rising at a few millimeters per year, right now. But we are seeing that sea level rise is accelerating - it's rising faster and faster. If you ask oceanographers what the oceans will be like by 2100, the general view is that it's going to be 1 meter higher than it is today.

He (not the op, the person in the cited article) does not actually say that it will cause sea level to rise, because that would be a lie. The ice shelf is already floating on the sea and will continue to float on the sea after it breaks away. No effect on sea level whatever. So he (again, the person in the article) gibbers about unknown future sea levels in order to create the impression that this break off will cause sea level to rise. It will not.

I have a problem with this kind of hyperbole. Global warming and its effects are real; a serious and major threat which we desperately need to address. Then we have buffoons like this guy who come out and say things that can be proven to be wrong, and that gives the morons, the deniers, ammunition.

There are plenty of facts, plenty of truths which can be cited to make the case for a global disaster. We do not need goofballs like this one coming along with his half truths and innuendo which actually damage the cause of trying to persuade action on global warming.

[NickB79]

3. The ice shelves act to hold back larger, grounded ice sheets

And THOSE glaciers have the potential to add feet of sea level rise in the next century. This has been discussed in the scientific community for years.

In fact, they directly quote in the article that the ice shelves stabilize the ice sheets!

This is common knowledge to anyone who's stayed abreast of what's happening in the Antarctic, and its frankly embarrassing that you didn't seem to already know this before ranting about "hyperbole" in climate change reporting.

[muriel_volestrangler]

4. He already said ice shelves hold back ice sheets

and ice sheets going into the ocean do cause sea level rise. So he's not 'gibbering', it's not 'hyperbole', and he's not a 'buffoon'.

See, for instance:

"Because the ice is already afloat it won’t affect sea level when it calves. But Larsen C holds back glaciers from the Antarctic Peninsula ice sheet, so losing the ice shelf altogether could also accelerate glacier loss."

https://www.newscientist.com/article/2133655-accelerating-antarctic-crack-will-hasten-calving-of-huge-iceberg/

[JayhawkSD]

5. No, he didn't answer the question.

The question was, "what are the consequences of all that ice going into the ocean?"

The answer is, "None, because that ice is already in the ocean."

There certainly are consequences to the ice no longer being present to stabilize the glaciers, but isn't the question that was asked, and the consequences of "that ice going into the ocean" are zero because it is already there. The reporter asked a stupid question and, instead of responding properly, the "expert" merely offered a lecture about rising sea levels, giving the impression that it would cause an immediate rise in sea level.

I know that some believe that every little signal of global warming should be treated as an immediate and disastrous cataclysm, that should be presented as immediate and horrendous doom, but all that does is give idiots the ability to say, "Oh look, that ice shelf broke off and all of the people who said it was going to cause sea level to rise were wrong."

[NickB79]

6. The seas are ALREADY rising, at an increasing rate in fact per recent studies

http://www.newsweek.com/climate-change-causes-sea-level-rise-accelerate-629463

"A study published in the journal Nature Climate Change shows that global sea level rise jumped by 50 percent from 1993 to 2014, the most recent year for which data are available. In 2014, sea levels rose 3.3 millimeters—more than an eighth of an inch—while in 1993 they ticked up 2.2 millimeters.

The paper found that melting of the Greenland ice sheet is the major new contributor. In 1993, it accounted for only 5 percent of the rise, but in 2014 it was responsible for one-quarter of the increase. The paper looked at satellite measurements and tide gauges, which measure sea levels around the world."

So no, idiots in the future can't look back and scoff, because we're already seeing effects TODAY. It is no longer theoretical.

But please, continue to tell us how we're not facing a cataclysm in the making.

http://voices.nationalgeographic.com/2016/11/03/unstoppable-destabilization-of-west-antarctic-ice-sheet-threshold-may-have-been-crossed/

"Losing all the ice shelves of Antarctica would be like losing each flying buttress that supported a gothic building. Collapse is the inevitable result. The question is how fast is the collapse in the case of an ice sheet that would, as Richard Alley told Congress in February 2007, slowly spread outwards and flatten like pancake batter that was just plopped on a griddle.

Nearly a decade later, the latest science indicates a critical threshold may have already been crossed.

Glaciologist Eric Rignot described this threshold—the retreat of ice in this part of Antartica and its draining into the Amundsen Sea could be “unstoppable.” Many scientists think this is a key region that can lead to the disintegration of the vast stores of marine ice in the West Antarctic Ice Sheet (Figure 1). The latest study by Khazendar, Rignot, and others adds to the mounting evidence that the threshold for an irreversible disintegration has begun."

You see, some of us can see beyond the tips of our noses. Extrapolating data into the future, and using that data to avert crises, is what humans are supposed to do. My daughter, for example, is only 7 years old. I am 37 years old. There is no doubt in my mind she will live long enough to indeed see the predicted doom as civilization falters under 3-4C of warming, and a good chance I will live long enough to see it too. This is simply based on current trend lines, and the lack of any counter-trends to offset the warming effects we're seeing.

Now gather round children, there is a story to be told!

Once upon a time, there was a stupid chicken in a coop. One night, a weasel got into the coop. The weasel started at the far end of the row of sleeping birds, and killed the first one. It made almost no noise, but it was just enough to wake up the stupid chicken. It looked down to see the weasel, but since the death of one of it's sisters didn't directly affect it, it didn't sound the alarm. The weasel killed the next chicken, and the next, and then next. Every time, the chicken said to itself "the immediate effects to me are zero, so clearly there is no danger. And if I speak up, the other chickens not directly in danger may laugh at me."

Finally, the weasel was at the last chicken's throat. The stupid one, who failed to see her doom despite clear warning, and ignored all opportunities to act and save herself.