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Scientists Have Reduced the Forecast of Sea Level Rise Seven Times Due To Melting of the Antarctic (maritimeherald.com)
The destruction of the Antarctic ice sheet may not lead to such a catastrophic rise in the level of the oceans, as previously thought. In a new study, the authors calculated that instead of growing by a meter or more by 2100, a growth of 14-15 cm is likely, writes N + 1. At the same time, the melting of the ice of Greenland and Antarctica is not fully taken into account in modern climate models, as it will lead to even more destabilization of the regional climate. Both studies on this are published in the journal Nature. An anonymous reader shares the report from Maritime Herald: In the first study, Tamzin Edwards from King's College London and her colleagues question this prediction. According to Edwards, who is quoted by the college press service, scientists re-analyzed data on ice loss and ocean level 3 million years ago, 125 thousand years ago and in the last 25 years and estimated the likelihood of rapid destruction of unstable sea areas of Antarctic glaciers, which the authors 2016 was associated with a meter increase in the level of the oceans. The hypothesis of such destruction received the abbreviated name MICI (marine ice cliff instability). They found that MICI does not necessarily explain the dynamics of sea level in the past, and without this the probability that the level will grow by more than 39 centimeters by 2100 is only about 5 percent. Edwards notes that in their model, even if the Antarctic glaciers really will collapse rapidly, the maximum increase in sea level will not exceed half a meter, and the most likely growth will be 14-15 cm. At the same time, scientists cannot completely eliminate the MICI phenomenon: they only talk about that more research is needed in this area.
In the second article, Edwards and Nick Golledge of Queen Victoria University in Wellington and their co-authors write that current climate models do not fully take into account the consequences of the destruction of the ice of Greenland and the Antarctic, which will slow down the Atlantic Ocean and further melt the Antarctic ice due to "locking" of warm water in the Southern Ocean (climatologists call such self-enhancing processes positive feedback processes). In addition, according to the authors of the article, the melting of ice in the warming scenario of 3-4 degrees compared with the middle of the XIX century will lead to a less predictable climate and an increase in the scale of extreme weather events.
In the second article, Edwards and Nick Golledge of Queen Victoria University in Wellington and their co-authors write that current climate models do not fully take into account the consequences of the destruction of the ice of Greenland and the Antarctic, which will slow down the Atlantic Ocean and further melt the Antarctic ice due to "locking" of warm water in the Southern Ocean (climatologists call such self-enhancing processes positive feedback processes). In addition, according to the authors of the article, the melting of ice in the warming scenario of 3-4 degrees compared with the middle of the XIX century will lead to a less predictable climate and an increase in the scale of extreme weather events.
Why? Because one study attempts to challenge an existing notion?
There are some things about AGW that are well understood. We know that CO2 absorbs some of the heat in the atmosphere, before it can radiate into space. We know that adding CO2 to the atmosphere will warm things up.
Some things science doesn't know: what are the effects of warming? How much warming will result from adding CO2 to the atmosphere? How much warming was there in the past? Of course, we have estimates for that last question, but the error bars are huge.
"First they came for the slanderers and i said nothing."
That the greens have predicted. I never thought you could do worse than economists and still be called a science. Maybe they should change their name to climate studies and be moved in with the gender studies people.
This is a dangerous and foolish attitude to take. The threats facing humanity raised by the "greens" -- your chosen term not mine -- are real, quantifiable, and ongoing and will not go away because a particular milestone has not been reached when predicted. There are crystal clear and very worrying trends across a range of domains such as climate, deforestation, availability of fresh water, insect populations, desertification, and pollution. Brushing them aside because the "apocalypse" hasn't happened yet is beyond silly.
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That the greens have predicted. I never thought you could do worse than economists and still be called a science. Maybe they should change their name to climate studies and be moved in with the gender studies people.
So one group publishes a pair of papers that predict a particular bad outcome of climate change will be less severe than previously predicted.... and climate science is terrible now?
You think this one pair of papers by one group is correct and disproves all the existing sea level rise predictions? You don't suppose they made a mistake in their analysis that some other group will find and publish a response?
For sea level rise in particular it's always been accepted that it's really hard to model which is why there's always massive ranges given.
At the same time I suppose you also think that Climate Science is some sort of conspiracy were they don't let any researchers break the party line. Lucky these folks were able to sneak their papers into an obscure little journal like Nature.
This is how science works, usually everyone is in general agreement but sometimes someone publishes an outlier, usually they're wrong but sometimes they're right and they become the new general agreement.
Hopefully this time the dissenting prediction is right because sea level rise is really bad!
I stole this Sig
https://www.nature.com/nature/...
The article that you quote was posted by a marketing manager. It looks to me as if he paraphrased a report he didn't understand. The article was from "The Maritime Herald", which is a on-line magazine mainly about shipping. The origin of the article is stated to be "Maritime News of Russia".
This article looks less reliable than most that are published here, and that's not any kind of praise.
I think we've pushed this "anyone can grow up to be president" thing too far.
This study does NOT say that that the total sea level will rise only 14cm. It's talking about the contribution of one single source of sea level rise: Antarctic Marine Ice Cliff Instability (MICI).
What happened was in 2016 a widely reported paper suggested that the IPCC's (rather gloomy) 2013 sea level projections needed to be revised upward by about 65-114 cm in the worst case because it didn't take MICI into account. Dr. Edward's paper suggests that MICI contribution would be closer to 45cm in the worst case, and only about 14cm in the most likely case. However this is still on top of the 52-98cm predicted by IPCC, most of which is due to highly predictable thermal expansion and not the chaotic behavior of ice systems.
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Hold up, you are confusing correlation with causation here. There is yet any scientific proof yet that this is the case
Yeah, this is one is well supported by experiment. See this for a demonstration. There are equations and references here.
Some scientists doubt that there will be a crisis because of AGW, but none doubt that adding CO2 to the atmosphere produces a warming effect.
I responded to you, but I admit I think you are ignorant and will not read the things I linked to.
"First they came for the slanderers and i said nothing."
They didn't take into account the possible breakup of Antarctic marine ice cliffs. It's not so simple as "it gets so warm that the ice in Antarctica melts"; we're talking about 2-4 degrees C on average, which is not enough to cause the ice there to melt. We're dealing with the consequences of a 2016 paper suggested that ice around the periphery of Antarctica could destablize. If those ice cliffs destablizied that would unlock ice stuck behind them, allow that ice to flow into the sea.
It's a dynamic process that involves the mechanical migration of still-perfectly-frozen ice from the land. Seriously, if we were talking about all the ice in Antarctica and Greenland actually melting, we'd be screwed on a scale nobody is suggesting likely. Far worse than the additional meter we were worried about on top of the meter we're almost certain to get.
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Hold up, you are confusing correlation with causation here. There is yet any scientific proof yet that this is the case.
You mean other than over a century of repeatable lab experiments? And basically our entire understanding of electromagnetism?
Ezekiel 23:20
I do not think it is a conspiracy. What I think is that mass hysteria makes it difficult to have any meaningful discussion on the subject of changing climate. It is all in the open which makes it difficult for anybody to claim conspiracy.
So where's the hysteria here?
Climate scientists have been very consistent that there will be some sea level rise, a big sea level rise is really bad, and that there's a lot of uncertainly about sea level rise, there might be a little or there might be a lot. It's just tough to model. And one of the big reasons is they think the ice caps could start sliding into the ocean and cause a huge sea level rise (MICI).
This group is saying they they don't think that even if the MICI happens it won't cause as big a rise as predicted.
All of that seems like reasonable good science. Sure a study that disagrees with the consensus introduces a bit more uncertainty into the field, but no one has ever claimed that sea level rise predictions were completely reliable.
I stole this Sig
The single largest contributor to the 52-98 cm of sea level rise we are expecting is thermal expansion, which is not chaotic at all. The ice is a huge wildcard which is responsible for the 46 cm of uncertainty in that figure.
This represents the most evidence-supported estimate we have to go on; assuming ice will contribute 0 is also making an unnecessarily precise prediction. We should act up on the best estimates we have; it's no different than predicting the track of a hurricane three days in advance. That track prediction is almost certainly somewhat off, but it's certainly actionable.
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Warming things up also puts a greater amount of H2O in the atmosphere. The world is mostly ocean. Oceans evaporate, which is why we have clouds. But not all H2O condenses as clouds. H2O has a much greater "greenhouse" effect than CO2.
Seven puppies were harmed during the making of this post.
Climate scientists have been very consistent that there will be some sea level rise, a big sea level rise is really bad, and that there's a lot of uncertainly about sea level rise, there might be a little or there might be a lot. It's just tough to model.
They haven't been very consistent. James Hansen, a very well respected climate scientist was predicting Manhattan would be under water.
That quote is wrong. I wouldn't quite call it a fake quote because the author was trying to be accurate, he just got a number wrong and forgot a critical piece of context.
Scientists are people, and sometimes they get carried away in the emotion of the moment, just like any other people. That's why we have reproducibility, to counter-act the effect of emotion. Reproducibility is the core of science.
On the topic of emotion, I've seen a lot of fake quotes on all sorts of subjects and I'm not sure I've ever fallen for one.
The reason is they're really easy to avoid.
Fake quotes are popular because they contradict the accepted persona of the person, for instance if a person is a Liberal the fake quote will be a Trump endorsement, a famous atheist will endorse religion, and if they're a climate scientist it will be an extreme prediction or admission of malfeasence.
But that also makes them really easy to spot, when you see a quote that's too good to be true all you need to do is check the sources and you'll figure out if it's real.
You got caught by that fake Hanson quote. Why is it?
Is your model of James Hansen and other climate scientists wrong, so you couldn't recognize a prediction they wouldn't give?
Or were you just too eager to use the quote that you didn't want to look too closely?
I stole this Sig
Hold up, you are confusing correlation with causation here. There is yet any scientific proof yet that this is the case
Yeah, this is one is well supported by experiment. See this for a demonstration. There are equations and references here. Some scientists doubt that there will be a crisis because of AGW, but none doubt that adding CO2 to the atmosphere produces a warming effect. I responded to you, but I admit I think you are ignorant and will not read the things I linked to.
It's not ignorance, so much as an unshakable belief set. There are many very intelligent folks on both sides of the Climate Change argument.
Sadly, political beliefs skewer scientific evidence, because it is one of the pillars in the us vs. them political landscape our democracy has devolved into.
Happiness in intelligent people is the rarest thing I know.
Ernest Hemingway
None of the intelligent ones doubt that CO2 warms the atmosphere to some degree. Or if there is an intelligent person who doubts it, I would like to meet them.
"First they came for the slanderers and i said nothing."
Chlorofluorocarbons (CFCs), chemicals found mainly in spray aerosols heavily used by industrialized nations for much of the past 50 years, are the primary culprits in ozone layer breakdown. When CFCs reach the upper atmosphere, they are exposed to ultraviolet rays, which causes them to break down into substances that include chlorine. The chlorine reacts with the oxygen atoms in ozone and rips apart the ozone molecule.
One atom of chlorine can destroy more than a hundred thousand ozone molecules, according to the the U.S. Environmental Protection Agency.
The ozone layer above the Antarctic has been particularly impacted by pollution since the mid-1980s. This region’s low temperatures speed up the conversion of CFCs to chlorine. In the southern spring and summer, when the sun shines for long periods of the day, chlorine reacts with ultraviolet rays, destroying ozone on a massive scale, up to 65 percent. This is what some people erroneously refer to as the "ozone hole." In other regions, the ozone layer has deteriorated by about 20 percent.
About 90 percent of CFCs currently in the atmosphere were emitted by industrialized countries in the Northern Hemisphere, including the United States and Europe. These countries banned CFCs by 1996, and the amount of chlorine in the atmosphere is falling now. Scientists had estimated it would take another 50 years for chlorine levels to return to their natural levels. In fact, in November 2018, the UN released a report saying that, based on the latest science, the ozone layer is on track to be fully healed within 50 years.
That's true, warmer air is moister which traps more heat, which is a positive feedback. But it can also result in more cloud formation, increasing albedo and reflecting more heat, which is a negative feedback. Yet clouds can reflect heat back down again too, and the amount varies with altitude.
There's a lot we don't know about cloud formation under those conditions, so a lot of uncertainty as to degree. Current thinking is that net feedback is somewhat positive. Bottom line: It's complicated.
Why would anyone engrave "Elbereth"?
One of the hardest elements to predict is the pace of ice-sheet melting. This should be the message here.
It will probably be tolerable in my lifetime, but the Greenland ice sheet alone holds enough water to raise sea levels 7 metres. And it is melting, it is just a question of how fast.
When you do something 7 times and get different answers each time, you a probably doing it wrong.
When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
Nope, you just need to dump politically motivated science, which like social sciences (again politically motivated) is not actually science at all
I wonder if they remember reading in history class that it was generally accepted that the earth was flat once upon a time.
Not only have we known that the Earth is round since the times of Ancient Greece, but we've had a reliable method for estimating its diameter since that time as well. Which makes me wonder what kind of weird history you were taught...
Ezekiel 23:20
Intelligence aside, the ability to receive and process evidence contrary to one's belief set is rarer than hen's teeth.
Happiness in intelligent people is the rarest thing I know.
Ernest Hemingway