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  • Top Israeli spy chief exposes his true identity in online security lapse | Israel | The Guardian
    https://www.theguardian.com/world/2024/apr/05/top-israeli-spy-chief-exposes-his-true-identity-in-online-security-laps
    https://i.guim.co.uk/img/media/d0177a36d4ac7727ebc14863deeeaa354e7a9a24/0_0_2500_1500/master/2500.jpg?width=1200&height=630&quality=85&auto=format&fit=crop&overlay-ali

    Exclusive: Yossi Sariel unmasked as head of Unit 8200 and architect of AI strategy after book written under pen name reveals his Google account

  • How Hollywood writers triumphed over AI – and why it matters | US writers’ strike 2023 | The Guardian
    https://www.theguardian.com/culture/2023/oct/01/hollywood-writers-strike-artificial-intelligence
    https://i.guim.co.uk/img/media/689771a4945d1c8d8a88bf3f3d759512c6110153/0_221_5292_3175/master/5292.jpg?width=1200&height=630&quality=85&auto=format&fit=crop&overlay-ali

    Hollywood writers scored a major victory this week in the battle over artificial intelligence with a new contract featuring strong guardrails in how the technology can be used in film and television projects.

    With terms of AI use finally agreed, some writers are breathing easier – for now – and experts say the guidelines could offer a model for workers in Hollywood and other industries. The writers’ contract does not outlaw the use of AI tools in the writing process, but it sets up guardrails to make sure the new technology stays in the control of workers, rather than being used by their bosses to replace them.

    The new rules guard against several scenarios that writers had feared, comedian Adam Conover, a member of the WGA negotiating committee, told the Guardian. One such scenario was studios being allowed to generate a full script using AI tools, and then demanding that human writer complete the writing process.

    Under the new terms, studios “cannot use AI to write scripts or to edit scripts that have already been written by a writer”, Conover says. The contract also prevents studios from treating AI-generated content as “source material”, like a novel or a stage play, that screenwriters could be assigned to adapt for a lower fee and less credit than a fully original script.

    For instance, if the studios were allowed to use chatGPT to generate a 100,000-word novel and then ask writers to adapt it, “That would be an easy loophole for them to reduce the wages of screenwriters,” Conover said. “We’re not allowing that.” If writers adapt output from large language models, it will still be considered an original screenplay, he said.

    Simon Johnson, an economist at MIT who studies technological transformation, called the new terms a “fantastic win for writers”, and said that it would likely result in “better quality work and a stronger industry for longer”.

    #Intelligence_artificielle #Scénaristes #Hollywood #Grève

  • Jared Kushner says Gaza’s ‘waterfront property could be very valuable’ | Jared Kushner | The Guardian
    https://www.theguardian.com/us-news/2024/mar/19/jared-kushner-gaza-waterfront-property-israel-negev
    https://i.guim.co.uk/img/media/924c5c95136a383dee2fe74a3d23b1bfe00fc139/404_0_2140_1285/master/2140.jpg?width=1200&height=630&quality=85&auto=format&fit=crop&overlay-ali

    L’équipe de Baiden c’est pathétique, mais le beau-fils de Trump arrive à faire encore mieux.

    Jared Kushner has praised the “very valuable” potential of Gaza’s “waterfront property” and suggested Israel should remove civilians while it “cleans up” the strip.

    The former property dealer, married to Donald Trump’s daughter Ivanka, made the comments in an interview at Harvard University on 15 February. The interview was posted on the YouTube channel of the Middle East Initiative, a program of Harvard’s Kennedy School of Government, earlier this month.

    Kushner was a senior foreign policy adviser under Trump’s presidency and was tasked with preparing a peace plan for the Middle East. Critics of the plan, which involved Israel striking normalisation deals with Gulf states, said it bypassed questions about the future for Palestinians.

    His remarks at Harvard gave a hint of the kind of Middle East policy that could be pursued in the event that Trump returns to the White House, including a search for a normalisation deal between Saudi Arabia and Israel.

    “Gaza’s waterfront property could be very valuable … if people would focus on building up livelihoods,” Kushner told his interviewer, the faculty chair of the Middle East Initiative, Prof Tarek Masoud. Kushner also lamented “all the money” that had gone into the territory’s tunnel network and munitions instead of education and innovation.

    “It’s a little bit of an unfortunate situation there, but from Israel’s perspective I would do my best to move the people out and then clean it up,” Kushner said. “But I don’t think that Israel has stated that they don’t want the people to move back there afterwards.”

    Masoud replied that there was “a lot to talk about there”.

    Kushner also said he thinks Israel should move civilians from Gaza to the Negev desert in southern Israel.

    He said that if he were in charge of Israel his number one priority would be getting civilians out of the southern city of Rafah, and that “with diplomacy” it could be possible to get them into Egypt.

    “But in addition to that, I would just bulldoze something in the Negev, I would try to move people in there,” he said. “I think that’s a better option, so you can go in and finish the job.”

    He reiterated the point a little later, saying: “I do think right now opening up the Negev, creating a secure area there, moving the civilians out, and then going in and finishing the job would be the right move.”

    The suggestion drew a startled response from Masoud. “Is that something that they’re talking about in Israel?” Masoud asked. “I mean, that’s the first I’ve really heard of somebody, aside from President Sisi [Egypt’s leader], suggesting that Gazans trying to flee the fighting could take refuge in the Negev. Are people in Israel seriously talking about that possibility?”

    “I don’t know,” Kushner replied, shrugging his shoulders.

    “That would be something you’d try to work on?” Masoud asked.

    “I’m sitting in Miami Beach right now,” Kushner said. “And I’m looking at the situation and I’m thinking: what would I do if I was there?”
    Israel should ‘finish the job’ by moving Palestinians to Negev, says Kushner – video

    Asked by Masoud about fears on the part of Arabs in the region that the Israeli prime minister, Benjamin Netanyahu, would not allow Palestinians who flee Gaza to return, Kushner paused and then said: “Maybe.”

    He went on to say: “I am not sure there is much left of Gaza at this point. If you think about even the construct, Gaza was not really a historical precedent [sic]. It was the result of a war. You had tribes in different places and then Gaza became a thing. Egypt used to run it and then over time different governments came in.”

    Responding to a question about whether the Palestinians should have their own state, Kushner described the proposal as “a super bad idea” that “would essentially be rewarding an act of terror”.

    • Kushner was a senior foreign policy adviser under Trump’s presidency and was tasked with preparing a peace plan for the Middle East.

      Si beau-papa repasse, je ne vois pas qui pourrait être plus qualifié que Jared pour se voir confier une mission de médiation au Proche-Orient.

      It’s a little bit of an unfortunate situation there,…

      oh pôvre !

      … but from Israel’s perspective

      tout est dit,

      I would do my best to move the people out and then clean it up.

      je crois qu’ils ne l’ont pas attendu.

  • CNN staff say network’s pro-Israel slant amounts to ‘journalistic malpractice’ | CNN | The Guardian
    https://www.theguardian.com/media/2024/feb/04/cnn-staff-pro-israel-bias
    https://i.guim.co.uk/img/media/86a4032d59628776965de090bb28c7fa8215152d/0_13_4000_2400/master/4000.jpg?width=1200&height=630&quality=85&auto=format&fit=crop&overlay-ali

    CNN is facing a backlash from its own staff over editorial policies they say have led to a regurgitation of Israeli propaganda and the censoring of Palestinian perspectives in the network’s coverage of the war in Gaza.

    Journalists in CNN newsrooms in the US and overseas say broadcasts have been skewed by management edicts and a story-approval process that has resulted in highly partial coverage of the Hamas massacre on 7 October and Israel’s retaliatory attack on Gaza.

  • Many prehistoric handprints show a finger missing. What if this was not accidental? | Archaeology | The Guardian
    https://www.theguardian.com/science/2023/dec/23/prehistoric-handprints-finger-missing-ritually-removed

    Men and women might have had their fingers deliberately chopped off during religious rituals in prehistoric times, according to a new interpretation of palaeolithic cave art.

    In a paper presented at a recent meeting of the European Society for Human Evolution, researchers point to 25,000-year-old paintings in France and Spain that depict silhouettes of hands. On more than 200 of these prints, the hands lack at least one digit. In some cases, only a single upper segment is missing; in others, several fingers are gone.

    In the past, this absence of digits was attributed to artistic licence by the cave-painting creators or to ancient people’s real-life medical problems, including frostbite.

    But scientists led by archaeologist Prof Mark Collard of Simon Fraser University in Vancouver say the truth may be far more gruesome. “There is compelling evidence that these people may have had their fingers amputated deliberately in rituals intended to elicit help from supernatural entities,” said Collard.

    Nor was the habit unique to one time or place, he added. “Quite a few societies encourage fingers to be cut off today and have done so throughout history.”

    Collard cited the Dani people from the New Guinea Highlands. “Women there sometimes have one or more fingers cut off following the death of loved ones, including sons or daughters. We believe that Europeans were doing the same sort of thing in palaeolithic times, though the precise belief systems involved may have been different. This is a practice that was not necessarily routine but has occurred at various times through history, we believe.”

    Collard and colleagues first published their finger amputation thesis a few years ago but were criticised by other scientists, who argued that the amputation of fingers would have been catastrophic for the people involved. Men and women without fully functioning hands would be unable to cope with the harsh conditions that prevailed millennia ago.
    Since then, Collard, working with PhD student Brea McCauley, has gathered more data to back the amputation thesis. In a paper presented at the European Society conference, they said their latest research provided even more convincing evidence that the removal of digits to appease deities explains the hand images in the caves in France and Spain.

    These paintings fall into two types: prints and stencils. In the former, a person placed his or her hand in pigment then pressed it on to a wall, creating a handprint. Stencils were created by placing a hand on a wall and then painting pigment over it to create a silhouette. In both cases, hands with missing digits were found among the wall art at four main sites; Maltravieso and Fuente del Trucho caves in Spain, and Gargas and Cosquer caves in France. The Cosquer caves, near Marseille, were the most recently discovered in 1985 by scuba diver Henri Cosquer.

    The team looked elsewhere for evidence of finger amputation in other societies and found more than 100 instances where it had been practised. “This practice was clearly invented independently multiple times,” they state. “And it was engaged in by some recent hunter-gatherer societies, so it is entirely possible that the groups at Gargas and the other caves engaged in the practice.”

    Nor were the examples confined to Europe, they add. Four sites in Africa, three in Australia, nine in North America, five in south Asia and one in south-east Asia contain evidence of finger amputation. “This form of self-mutilation has been practised by groups from all inhabited continents,” said Collard. “More to the point, it is still carried out today, as we can see in the behaviour of people like the Dani.”

    Collard pointed to rituals still carried out in Mauritius and other places, such as fire-walking, face-piercing with skewers and putting hooks through skin so a person can haul heavy chains behind them. “People become more likely to cooperate with other group members after going through such rituals. Amputating fingers may simply have been a more extreme version of this type of ritual.”

    https://i.guim.co.uk/img/media/b0ec3867db424e8e9112239d87ace69807d32501/0_175_3728_2237/master/3728.jpg?width=620&dpr=1&s=none
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  • ‘Impossible’ to create AI tools like ChatGPT without copyrighted material, OpenAI says | OpenAI | The Guardian, repéré par @biggrizzly
    https://www.theguardian.com/technology/2024/jan/08/ai-tools-chatgpt-copyrighted-material-openai
    https://i.guim.co.uk/img/media/ca6af0b84989aedf106fbbbce585433f792443f7/0_0_4276_2566/master/4276.jpg?width=620&dpr=1&s=none

    “Because copyright today covers virtually every sort of human expression – including blogposts, photographs, forum posts, scraps of software code, and government documents – it would be impossible to train today’s leading AI models without using copyrighted materials,” said OpenAI in its submission, first reported by the Telegraph.

    It added that limiting training materials to out-of-copyright books and drawings would produce inadequate AI systems: “Limiting training data to public domain books and drawings created more than a century ago might yield an interesting experiment, but would not provide AI systems that meet the needs of today’s citizens.”

  • Health inequalities ‘caused 1m early deaths in England in last decade’ | Inequality | The Guardian
    https://www.theguardian.com/inequality/2024/jan/08/england-deaths-inequality-poverty-austerity-covid-study-public-health
    https://i.guim.co.uk/img/media/403b7b855c99ce4ff336c696244da1cedbdfe16c/0_301_4592_2755/master/4592.jpg?width=1200&height=630&quality=85&auto=format&fit=crop&overlay-ali

    More than 1 million people in England died prematurely in the decade after 2011 owing to a combination of poverty, austerity and Covid, according to “shocking” new research by one of the UK’s leading public health experts.

    The figures are revealed in a study by the Institute of Health Equity at University College London led by Sir Michael Marmot. They demonstrate the extent to which stark economic and social inequalities are leading to poorer people dying early from cancer, heart problems and other diseases.

    ‘1 Million Early Deaths in England’

    1 million+ poorer people in England died prematurely over a decade from cancer, heart problems, and other diseases, a “dismal” new study finds.

    Government austerity measures and COVID-19 led to “stark economic and social inequalities” that worsened outcomes, The Guardian reports.

    The study: For the Health Inequalities, Lives Cut Short report, researchers at the Institute of Health Equity at University College London analyzed life expectancies of people across England who do not live in the wealthiest 10% of areas between 2011 and 2019.

    The findings:

    1 million+ people died earlier than they would have if they lived in those rich areas.

    148,000 of those deaths were linked to economic austerity measures implemented in 2010.

    Pandemic-era inequalities led to an additional 28,000 excess deaths.

    People in the U.K. fared worse in “healthy life years”—how long someone lives free of ill health—compared with E.U. countries.

    The Quote: “Our country has become poor and unhealthy, where a few rich, healthy people live,” said IHE leader Sir Michael Marmot, who described the mounting inequality as a “shocking political failure.”

    Only one other developed country, said Marmot, fares worse in terms of inequality: the U.S.

    #Santé_publique #UK #Inégalités

  • Everything politicians tell you about immigration is wrong. This is how it actually works | Hein de Haas | The Guardian
    https://www.theguardian.com/commentisfree/2023/dec/29/politicians-immigration-wrong-cheap-labour
    https://i.guim.co.uk/img/media/6e53b5beb207e5e821a2c7f58bdb45714b46e31e/0_0_2560_1536/master/2560.jpg?width=1200&height=630&quality=85&auto=format&fit=crop&overlay-ali

    Everything politicians tell you about immigration is wrong. This is how it actually works
    Hein de Haas
    We seem to be living in times of unprecedented mass migration. Images of people from Africa crammed into unseaworthy boats desperately trying to cross the Mediterranean, asylum seekers crossing the Channel into Britain, and “caravans” of migrants trying to reach the Mexico-US border all seem to confirm fears that global migration is spinning out of control. A toxic combination of poverty, inequality, violence, oppression, climate breakdown and population growth appear to be pushing growing numbers of people from Africa, Asia and Latin America to embark upon desperate journeys to reach the shores of the wealthy west.
    All of this results in the popular idea of a “migration crisis” that will require drastic countermeasures to prevent massive waves of people arriving in the future, apparently exceeding the absorption capacity of western societies and economies. Despite this, however, there is no scientific evidence to sustain the claim that global migration is accelerating. International migrants account for about 3% of the world population, and this percentage has remained remarkably stable over the past half a century. Likewise, refugee migration is much more limited than political rhetoric and media images suggest. About 10% of all international migrants are refugees, representing 0.3% of the world population. While refugee flows fluctuate strongly with levels of conflict, there is no evidence of a long-term increasing trend. About 80-85% of refugees remain in regions of origin, and that share has also remained rather stable over the past decades. And there is no evidence that illegal migration is spinning out of control – in fact, the large majority of migrants who move from the global south to the global north continue to move legally. For instance, nine out of 10 Africans move to Europe legally, with passports and papers in hand.
    The evidence also turns common understandings of the causes of migration on its head. The conventional view is that south-to-north migration is in essence the outgrowth of poverty, inequality and violence in origin countries – hence the popular idea that poverty reduction and development are the only long-term solutions to migration. However, this assumption is undermined by evidence showing that migration rises as poor countries become richer. This is because increasing levels of income and education, alongside infrastructure improvements, raise people’s capabilities and aspirations to migrate. Instead of the stereotypical “desperate flight from misery”, in reality migration is generally an investment in the long-term wellbeing of families and requires significant resources. Poverty actually deprives people of the resources required to move over long distances, let alone to cross continents.
    This is also one of the many reasons why, contrary to common assumptions, climate breakdown is unlikely to trigger mass movements of “climate refugees”. Research on the effects of droughts and flooding shows that most people will stay close to home. In fact, the most vulnerable people are most likely to get trapped, unable to move out at all. It is no coincidence that most migrants come from middle-income countries such as India and Mexico. The paradox is that any form of development in the poorest countries of the world – such as in sub-Saharan Africa – is therefore likely to increase their future emigration potential. Still, despite global averages remaining stable, it is difficult to deny that legal immigration to the US, Britain and western Europe has been growing over the past decades. The frequent discontent this has caused has gone along with repeated calls for less, more controlled or more selective immigration. But border crackdowns have clearly failed to achieve these objectives or have even made problems worse because they were not based on an understanding of how migration really works. The main reason is that these policies ignored the most important root cause of migration: persistent labour demand.
    The misleading assertion that poverty causes migration conceals the fact that labour demand has been the main driver of growing immigration to western countries since the 1990s. More widespread education, women’s emancipation and population ageing have led to labour shortages; these have fuelled a growing demand for migrant workers in sectors such as agriculture, construction, cleaning, hospitality, transport and food processing, as supplies of local workers willing and able to do such jobs have increasingly run dry. Without such chronic labour shortages, most migrants wouldn’t have come. But this hasn’t been a natural process. It is instead one that has been encouraged by decades of policies geared towards economic and labour market liberalisation, which have fuelled the growth of precarious jobs that local workers won’t take. Politicians from left to right know this reality, but they don’t dare admit it out of fear of being seen as “soft on immigration”. They choose instead to talk tough and revert to acts of political showmanship that create an appearance of control, but that in effect function as a smokescreen to conceal the true nature of immigration policy. Under this current arrangement, more and more migrants are allowed in, and the employment of undocumented workers is widely tolerated as they fill in crucial labour shortages.
    Politicians have turned a blind eye as proven by almost laughably low levels of workplace enforcement. To break away from this legacy of failed policies, politicians need to gather the courage to tell an honest story about migration: that it is a phenomenon that benefits some people more than others; that it can have downsides for some, but cannot be thought or wished away; and that there are no simple solutions for complex problems. Fundamental choices have to be made. For example, do we want to live in a society in which more and more work – transport, construction, cleaning, care of elderly people and children, food provision – is outsourced to a new class of servants made up mainly of migrant workers? Do we want a large agricultural sector that partly relies on subsidies and is dependent on migrants for the necessary labour? The present reality shows that we cannot divorce debates about immigration from broader debates about inequality, labour, social justice and, most importantly, the kind of society we want to live in.
    Hein de Haas is professor of sociology at the University of Amsterdam, and the author of How Migration Really Works

    #Covid-19#migrant#migration#flux#pauvrete#globalmigration#climat#afrique#asie#ameriquelatine#travailleurmigrant#economie#inegalite#sante

  • Guide des onomatopées japonaises
    ‘Pachi pachi’ or ‘kachi kachi’ ? Japan launches foreigners’ guide to tricky world of onomatopoeia | Japan | The Guardian
    https://www.theguardian.com/world/2023/nov/15/mie-prefecture-guide-pachi-pachi-or-kachi-kachi-a-foreigners-guide-to-t

    Pour l’instant les descriptions sont disponibles en chinois, vietnamien, népalais et indonésien.
    https://uploads.guim.co.uk/2023/11/16/%E3%80%8C%E7%B5%B5%E3%81%8B%E3%82%89%E9%9F%B3%E3%81%8B%E3%82%99%E3%8
    https://i.guim.co.uk/img/media/d3005c172613a3455f4fe43d3d7d14cd91c42409/0_0_1477_1049/master/1477.jpg?width=620&dpr=1&s=none

  • Crew radio leak increases outrage over Greek ferry passenger pushed into sea | Greece | The Guardian
    https://www.theguardian.com/world/2023/sep/13/greece-ferry-passenger-sea-death-crew-radio-recordings-conversations-le
    https://i.guim.co.uk/img/media/6e949be5d5c932468532afc4ca80c

    Recordings of conversations appear to reveal racist attitudes among crew in connection with death of Antonis Karyotis

    Outrage over the drowning of a passenger who was pushed from the ramp of a Greek ferry has mounted after leaked recordings of radio conversations appeared to reveal racist attitudes among the crew.

    In one extract, the ship’s master is apparently heard saying that he thought the passenger, subsequently identified as a Greek, was a foreigner.

    “I thought he didn’t have a ticket,” he said. “I thought he was black, a Pakistani … He was sitting there outside, going round and round, but he didn’t show me any ticket. The only thing he told me was, ‘I am going to travel.’”

    In another snippet aired by the Greek TV channel ANT1, another crew member is heard telling his colleagues not to say what they have seen. “You should always have one thing in mind: we never say what we hear and what we see,” he says.

    It was unclear how the conversations were released, although they are believed to have been automatically recorded on board.

    The drowning of Antonis Karyotis on 5 September has sent shockwaves through the seafaring nation.

    Footage shows Karyotis running on to the gangplank just as the Crete-bound vessel is about to leave the country’s main port of Pireaus. Crew members can be seen trying to stop him, before one shoves the 36-year-old three times and he slips, dangles momentarily from the ships’ ramp, and falls into the sea. It later emerged that Karyotis had bought a ticket.

  • Strange sightings: are there really UFOs in Port Talbot? – in pictures | Art and design | The Guardian
    https://www.theguardian.com/artanddesign/gallery/2023/aug/23/ufos-in-port-talbot-roo-lewis-photographer-in-pictures

    https://i.guim.co.uk/img/media/c5178e39fa4d802a3a27dde9356caaa85bba5230/0_0_4000_3200/master/4000.jpg?width=1010&quality=85&auto=format&fit=max&s=087703e000937d7ae36cf

    Dunes
    Lindz dancing on the dunes of Kenfig. Lewis writes: ‘The town revolves around the steelworks like living room furniture pointing at the television set. But within a few minutes’ walk you can go from the top of a mountain over sand dunes to the longest beach in Wales. Every summer the sea glows a fluorescent blue hue from visiting plankton. All under the watchful eye of one of the largest integrated steelworks in the world’

  • Gulf stream could collapse as early as 2025, study suggests | Climate crisis | The Guardian
    https://www.theguardian.com/environment/2023/jul/25/gulf-stream-could-collapse-as-early-as-2025-study-suggests
    https://i.guim.co.uk/img/media/c48440be715898be21be5636ac64d179db67ec45/0_0_3500_2102/master/3500.jpg?width=1200&height=630&quality=85&auto=format&fit=crop&overlay-ali

    Prof Niklas Boers, from the Potsdam Institute for Climate Impact Research in Germany, revealed the early warning signs of Amoc collapse in 2021. “The results of the new study sound alarming but if the uncertainties in the heavily oversimplified model [of the tipping point] and in the underlying [sea temperature] data are included, then it becomes clear that these uncertainties are too large to make any reliable estimate of the time of tipping.”

    Prof David Thornalley, at University College London, UK, agreed the study had large caveats and unknowns and said further research was essential: “But if the statistics are robust and a relevant way to describe how the actual Amoc behaves, then this is a very concerning result.”

    Dr Levke Caesar, at the University of Bremen, Germany, said using sea surface temperatures as proxy data for the strength of the Amoc currents was a key source of uncertainty: “We only have direct observational data of the Amoc since 2004.”

    The extrapolation in the new analysis was reasonable, according to Prof Tim Lenton, at the University of Exeter, UK. He said the tipping point could lead to a partial Amoc collapse, for example only in the Labrador Sea, but that this would still cause major impacts. Divlitsen said he hoped the debate would drive new research: “It’s always fruitful when you do not exactly agree.”

    Prof Stefan Rahmstorf, at the University of Potsdam, Germany, said: “There is still large uncertainty where the Amoc tipping point is, but the new study adds to the evidence that it is much closer than we thought. A single study provides limited evidence, but when multiple approaches have led to similar conclusions this must be taken very seriously, especially when we’re talking about a risk that we really want to rule out with 99.9% certainty. Now we can’t even rule out crossing the tipping point in the next decade or two.”

    • le titre de l’article est trompeur (Gulf stream en lieu et place d’AMOC)

      Le Gulf Stream va-t-il sauver l’Europe du changement climatique ?
      https://bonpote.com/le-gulf-stream-va-t-il-sauver-leurope-du-changement-climatique

      Après avoir quitté la côte américaine, une partie de l’eau transportée par le #Gulf_Stream (de l’ordre de 20 %) circule, en surface, vers le nord, puis traverse le bassin d’ouest en est vers 50°N. Ensuite elle rejoint soit les mers d’Irminger et du Labrador qui entourent la pointe Sud du Groenland, soit encore plus au nord les côtes norvégiennes.

      La chaleur transportée est transférée dans l’atmosphère, surtout en hiver, ce qui rend l’eau en surface plus lourde. C’est pourquoi dans ce parcours, elle a tendance à “couler” en profondeur où elle alimente les courants profonds qui s’orientent en moyenne vers le sud.

      Dans l’ensemble, cette circulation occupe tout l’#océan_Atlantique, et s’oriente vers le nord proche de la surface et vers le sud en profondeur, ce qui décrit une boucle de retournement, d’où la dénomination française de circulation de retournement (et en anglais #AMOC pour Atlantic Meridional Overturning Circulation).

      Ce qu’il faut surtout retenir, c’est que cette circulation n’est pas un seul courant, mais une moyenne, une construction mathématique qui regroupe, fusionne plusieurs courants différents dans tout l’Atlantique Nord, dont le Gulf Stream. Sa définition ne s’arrête pas à l’équateur : on la calcule aussi dans l’hémisphère sud et dans tous les autres bassins.

      Comment connaît-on ces phénomènes et comment les étudie-t-on ?
      Comment observe-t-on le Gulf Stream ?

      Le Gulf Stream, courant océanique bien connu des marins depuis le XVIème siècle et dont la température chaude est mesurée dès le XVIIIème par Benjamin Franklin, est observé régulièrement par des navires océanographiques depuis bientôt un siècle. On mesure son intensité en continu grâce à un câble sous-marin entre la Floride et les Bahamas depuis les années 1980. On l’observe par satellite depuis les années 1990. La situation n’a rien de comparable pour la circulation de retournement…

      Comment observe-t-on la circulation de retournement ?
      Depuis 2004, un ensemble d’instruments océanographiques sont disposés le long d’une ligne imaginaire qui relie la côte Est des États-Unis à l’Afrique à la latitude 26°N, de la surface jusqu’au fond de l’océan. Cette section océanographique permet de mesurer en continu l’intensité de la circulation de retournement.

      Parce que ces observations directes restent peu nombreuses, les océanographes ont beaucoup recours aux modèles numériques pour étudier la circulation de retournement et ses impacts. Ces outils, basés sur la mécanique des fluides, les mathématiques et les sciences du calcul intensif, permettent de réaliser des expériences virtuelles pour tester des hypothèses (quel serait l’impact sur le climat en Europe d’un arrêt de la circulation de retournement ?) et tenter de reproduire les océans actuels, passés et futurs.

      Enfin, les paléo-océanographes essaient de reconstruire les fluctuations de la circulation de retournement en utilisant des mesures indirectes de son intensité, estimées à partir de divers prélèvements sédimentaires terrestres et marins.

      Historiquement, on pensait que la circulation de retournement était entraînée presque exclusivement par les contrastes, liés à la température et la salinité (d’où la dénomination de circulation “thermohaline”). On sait maintenant que d’autres processus physiques l’influencent, comme le vent et le mélange océanique.

      On sait aussi, notamment grâce aux modèles numériques et aux mesures directes récentes, qu’elle fluctue beaucoup d’un mois sur l’autre, d’un an sur l’autre, d’une décennie sur l’autre, d’un siècle sur l’autre… et que ces fluctuations peuvent être déclenchées par de nombreux processus différents (parmi lesquels la fonte du Groenland, mais pas que…).

      L’un des courants marins les plus complexes au monde
      Le Gulf Stream est également lui-même un des courants marins les plus complexes au monde car sous influence de multiples processus. La circulation de retournement hérite de cette complexité. Mais en tant que construction mathématique qui fusionne plusieurs courants marins dont le Gulf Stream, elle est aussi influencée par d’autres processus océaniques.

      On entend parfois que la circulation de retournement n’existe pas car les mesures RAPID à 26°N ne correspondent pas à celles prises plus au sud ou plus au nord. Ces différences, au contraire, illustrent bien que la circulation de retournement n’est pas un simple tapis roulant qui connecte l’océan Atlantique du sud au nord, comme des représentations simplifiées de l’océan ont pu le laisser à penser.

    • Scientists have long seen the Atlantic Meridional Overturning Circulation, or AMOC, as one of the planet’s most vulnerable “tipping elements” — meaning the system could undergo an abrupt and irreversible change, with dramatic consequences for the rest of the globe.
      Under Earth’s current climate, this aquatic conveyor belt transports warm, salty water from the tropics to the North Atlantic, and then sends colder water back south along the ocean floor. But as rising global temperatures melt Arctic ice, the resulting influx of cold freshwater has thrown a wrench in the system — and could shut it down entirely.

      https://www.washingtonpost.com/climate-environment/2023/07/25/atlantic-ocean-amoc-climate-change

      #AMOC : Atlantic Meridional Overturning Circulation (Circulation méridienne de retournement de l’Atlantique)

    • Les effets estimés d’un arrêt de l’AMOC :


      À gauche les températures, à droite les précipitations. À noter que ces valeurs sont une moyenne annuelle, or un des effets de l’arrêt de l’AMOC notamment dans les hautes latitudes serait un renforcement de la saisonnalité, chose qui n’est pas reflétée par les valeurs annuelles.
      L’Europe serait « sibérianisée », avec des hivers nettement plus longs (car commençant plus tôt) et plus froids (surtout en Europe du Nord), des étés plus courts (mais pas forcément plus frais), et des pluies en diminution (jusqu’à moitié moins sur la péninsule ibérique) car un Atlantique Nord plus froid évaporerait moins. On estime que la surface cultivable en blé et maïs en Europe serait réduite de plus de moitié.
      En Amérique du Nord il y aurait augmentation de la pluviométrie mais sous forme de tempêtes plus fréquentes.
      En Afrique de l’Ouest la zone très peuplée entre Sénégal et Gabon subirait une sécheresse et un réchauffement accrus (car la chaleur n’étant plus transportée vers le nord s’accumulerait dans les tropiques)
      Tout l’hémisphère Sud se réchaufferait, et la forêt amazonienne disparaîtrait encore plus vite sous l’effet de sécheresses accentuées (en relarguant son carbone au passage).
      Les courants de Humbolt (Chili Pérou) et du Benguéla (Namibie Angola) s’affaibliraient, la pêche dans ces secteurs (très importante aujourd’hui) ne donnerait plus grand chose, et l’océan global perdrait beaucoup de sa productivité et de sa capacité à absorber le CO2. Maigre consolation les déserts d’Atacama et du Namib seraient moins désertiques, le Nord-Est brésilien moins aride, mais probablement pas de quoi accueillir des centaines de millions de réfugiés climatiques.

    • d’après cette simulation la Méditerranée et l’Afrique du Nord seraient également touchées par le refroidissement de l’Atlantique Nord, la chaleur resterait piégée plus au Sud. Si on y ajoute la baisse des précipitations dans tout le pourtour méditerranéen, le Sahara s’étendrait en quelque-sorte à la fois sur le Maghreb et sur le Sahel.

  • Europe should cap ‘luxury’ energy use to meet emissions targets, study says | Energy | The Guardian
    https://www.theguardian.com/environment/2023/jul/17/europe-cap-luxury-energy-use-emissions-carbon-budget-targets-study
    https://i.guim.co.uk/img/media/af4b55a2fabe50fffc6246cf77e4e0eccd9b9744/1308_844_4304_2582/master/4304.jpg?width=1200&height=630&quality=85&auto=format&fit=crop&overlay-ali

    Gently limiting “luxury” demand from the 20% of European consumers who use the most energy saves seven times the amount of planet-heating gases that would be emitted in meeting the basic needs of the 20% who use the least energy, researchers have found.

    The study, which modelled the effect of narrowing the gaps in energy use between households within 27 European countries, found capping demand from the top fifth, even at a fairly high level, cut greenhouse gas pollution from energy consumption by 9.7%, while raising demand from people in the bottom fifth who also live in poverty to a fairly low level increases emissions by just 1.4%.

    “We have to start tackling luxury energy use to stay within an equitable carbon budget for the globe,” said Milena Buchs, a professor of sustainable welfare at the University of Leeds and the lead author of the study, published on Monday in the journal Nature Energy, “but also to actually have the energy resources to enable people in fuel poverty to slightly increase their energy use and meet their needs.”

    To stop the planet heating beyond the levels agreed to by world leaders, rich countries must quickly clean up their supply of energy and cut demand for it. The Intergovernmental Panel on Climate Change (IPCC) found in its latest review of the science that demand-side strategies can slash global emissions 40-70% by 2050 compared with business as usual.

  • Will El Niño on top of global heating create the perfect climate storm? | Climate crisis | The Guardian
    https://www.theguardian.com/environment/2023/jul/03/a-perfect-storm-scientists-ponder-if-climate-has-entered-a-new-erratic-
    https://i.guim.co.uk/img/media/3de9780af1df091c9318b572fa4ef2183fb7f2c3/0_0_4936_2962/master/4936.jpg?width=1200&height=630&quality=85&auto=format&fit=crop&overlay-ali

    Very unusual”, “worrying”, “terrifying”, and “bonkers”; the reactions of veteran scientists to the sharp increase in north Atlantic surface temperatures over the past three months raises the question of whether the world’s climate has entered a more erratic and dangerous phase with the onset of an El Niño event on top of human-made global heating.

    Since April, the warming appears to have entered a new trajectory. Meanwhile the area of global sea ice has dropped by more than 1 million sq km below the previous low.

    “If a few decades ago, some people might have thought climate change was a relatively slow-moving phenomenon, we are now witnessing our climate changing at a terrifying rate,” said Prof Peter Stott, who leads the UK Met Office’s climate monitoring and attribution team. “As the El Niño builds through the rest of this year, adding an extra oomph to the damaging effects of human-induced global heating, many millions of people across the planet and many diverse ecosystems are going to face extraordinary challenges and unfortunately suffer great damage.”