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    TUHOKlimaticka zmena / If the fracturing of our once stable climate doesn’t terrify you, then you don’t fully understand it


    "Given the sheer enormity of climate change, it’s okay to be depressed, to grieve. But please, don’t stay there too long. Join me in pure, unadulterated, righteous anger."


    "I don’t want your hope. I don’t want you to be hopeful. I want you to panic. I want you to feel the fear I feel every day. And then I want you to act. Once you start to act, the hope is everywhere."

    "Our best scientists tell us insistently that a calamity is unfolding, that the life-support systems of the Earth are being damaged in ways that threaten our survival. Yet in the face of these facts we carry on as usual."

    “We’ve got to stop burning fossil fuels. So many aspects of life depend on fossil fuels, except for music and love and education and happiness. These things, which hardly use fossil fuels, are what we must focus on.”

    A nejde o to, že na to nemáme dostatečné technologie, ty by na řešení použít šly, ale chybí nám vůle a představivost je využít. Zůstáváme při zemi, přemýšlíme až moc rezervovaně. Technologický pokrok to sám o sobě nevyřeší. Problém jsme my, ne technologické nástroje.

    Rostouci hladiny oceanu, zmena atmosferickeho proudeni, zmeny v distribuci srazek a sucha. Zmeny karbonoveho, fosforoveho a dusikoveho cyklu, okyselovani oceanu. Jake jsou bezpecnostni rizika a jake potencialni klady dramatickych zmen fungovani zemskeho systemu?
    Ale take jak funguji masove dezinformacni kampane ropneho prumyslu a boj o verejne mineni na prahu noveho klimatickeho rezimu post-holocenu.
    rozbalit záhlaví
    TUHO
    TUHO --- ---
    TUHO: Tady kdyztak summary 30 let prace Rahmstorfa na tema. Relativne kratkej clanek, hodne dat, obrazku, srozumitelny pro vetsinu lidi

    The Atlantic Meridional Overturning Circulation has a major impact on climate, not just in the northern Atlantic but globally. Paleoclimatic data show it has been unstable in the past, leading to some of the most dramatic and abrupt climate shifts known. These instabilities are due to two different types of tipping points, one linked to amplifying feedbacks in the large-scale salt transport and the other in the convective mixing that drives the flow. These tipping points present a major risk of abrupt ocean circulation and climate shifts as we push our planet further out of the stable Holocene climate into uncharted waters.

    Is the Atlantic Overturning Circulation Approaching a Tipping Point? | Oceanography
    https://tos.org/oceanography/article/is-the-atlantic-overturning-circulation-approaching-a-tipping-point
    TADEAS
    TADEAS --- ---
    Weather Whiplashing and Jetstream Waviness
    https://youtu.be/RS_0GNk_CfE?si=pAEyL8ImmySD5UrI



    The Climate Emergency Forum welcomes Dr. Jennifer Francis to discuss two of her recent papers on Weather Whiplashing, which is defined as an abrupt shift from one persistent set of often extreme weather conditions to another.

    This video was recorded on February 27th, 2024, and published on March 10th, 2024.

    Dr. Francis introduces the concept of weather whiplashing and provides examples like sudden temperature drops and shifts from drought to heavy rain, highlighting the impact of these events on regions like Florida and California. Dr. Francis explains how weather whiplash events are diagnosed by analyzing patterns in the jet stream using self-organizing maps, emphasizing the role of the Arctic's warming in increasing the frequency of these events.

    The dialogue delves into the intricate relationship between atmospheric patterns, jet stream dynamics, and weather phenomena. Dr. Francis illustrates how anomalies in the upper-level atmosphere can lead to significant shifts in weather patterns, affecting regions like Florida with freeze events and temperature extremes. She discusses the use of AI tools to analyze atmospheric patterns over time and predict future trends in weather whiplash events, particularly focusing on scenarios where the Arctic's warming plays a crucial role in driving these shifts.

    Participants engage in a thought-provoking discussion on the complexities of jet stream behavior, climate factors influencing atmospheric dynamics, and implications for global weather patterns. Questions raised by participants highlight key aspects such as variations in jet stream configurations, heat transfer between equator and poles, and the impact of Arctic warming on jet stream speed and waviness.

    Dr. Francis addresses inquiries about ocean currents' correlation with jet stream patterns and explains how subtleties in jet streams affect phenomena like record low transit times for airplanes flying across continents. The dialogue underscores the interdisciplinary nature of climate research and the interconnectedness of various environmental factors shaping our planet's weather systems.


    https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022JD036717
    PALEONTOLOG
    PALEONTOLOG --- ---
    SEJDA: One emerging argument is that the Anthropocene should be defined as an event in geological history — similar to the rise of atmospheric oxygen just over two billion years ago, known as the Great Oxidation Event — but not as a formal epoch. This would make more sense because geological events unfold as transformations over time, such as humans industrializing and polluting the planet, rather than as an abrupt shift from one state to another, says Erle Ellis, an ecologist at the University of Maryland Baltimore County in Baltimore.
    TADEAS
    TADEAS --- ---
    climate minsky moment

    důchody v ohrožení .)


    Minsky moment: are pension assets at risk due to flawed climate analysis? | Netzeroinvestor
    https://www.netzeroinvestor.net/news-and-views/are-millions-of-pensions-at-risk-due-to-flawed-climate-analysis

    Widespread reliance on flawed research generates a disconnect between current investment decision making, which assumes relatively trivial impacts from climate change, and the likely real-world effects of global warming, Keen warned.

    "To ensure that the world moves into a new climate secure energy system, it’s crucial pension schemes send the market the right investment signals,” said Mark Campanale, the founder of Carbon Tracker.

    “The signal has to be that a swift, orderly transition is in everyone’s financial interests, particularly for scheme beneficiaries.”

    However, the relationship between economics, climate science and assessing financial risk is not a “comfortable one,” he continued, adding that “the advice pension schemes are receiving risks trivialising the potentially huge damage climate change will have to asset values."

    Campanale stressed that “these flawed climate risk models” are used throughout the financial system, lulling economic decision makers, from pension funds to central banks, into a false sense of security.

    “The result is cavalier positions such as US Federal Reserve Board Governor Christopher Waller who announced: ‘Climate change is real, but I do not believe it poses a serious risk to the safety and soundness of large banks or the financial stability of the United States’,” he said.

    The report issues a direct warning to asset owners for the serious prospect of an “unpleasant, abrupt and wealth destroying” so-called “Climate Minsky moment” with a sudden collapse in asset values as financial markets wake up to the gap between mainstream economist forecasts and the reality of climate impacts.

    Keen, who is also the former head of the School of Economics, History and Politics at Kingston University, London, contrasts scientists’ empirical research with predictions by climate economists that are “a ‘hunch’ based on rather spurious assumptions for global warming, which have been used to generate equally spurious estimates of damages to future GDP.”

    He underscored that global warming, at less than 1.5°C, is already affecting people and companies across the planet, pointing at record heatwaves, floods, and intensifying storms as they halt commerce, damage crops, create uninsurable areas, and impair infrastructure.

    Keen singled out scientific research which finds that exceeding the 1.5°C Paris target would be “dangerous”, passing 3°C would be “catastrophic”, and reaching 5°C will be “beyond catastrophic, raising existential threats”.

    Yet, despite scientific predictions, a survey of 738 climate economics papers in a number of top academic journals found the median prediction of economists was that 3°C of warming would reduce global GDP by just 5%, and warming of 5°C would see a 10% reduction.

    ...

    The researchers singled out investment managers and consultants such as Aon Hewitt, Hymans Robertson and Mercer as they "continue to rely on flawed research" when they advise pension funds on the impacts of global warming on members’ portfolios.

    For example, Mercer, in advice to Australian fund HESTA predicts only a -17% portfolio impact by 2100 in a 4°C scenario. It states that its model primarily reflects coastal flood damage and does not take account of climate tipping points.

    Mercer also advises LGPS Central, which manages £28.5 billion of retirement savings for a million members of Local Government Pension Schemes in the UK.

    One of these schemes, Shropshire County Pension Fund, told members that a trajectory leading to 4°C by 2100 would only reduce annual returns by 0.06% in 2030 and 0.1% by 2050, saying that it relied on LGPS Central for information.

    Moreover, in a 2022 report, Australian superannuation firm Unisuper concluded that even in a “worst case scenario” involving a 4.3°C increase in global temperatures by 2100, “the overall risk to our portfolio is acceptable.”

    “Each layer in the process of assessing the risks of climate change has assumed that the previous layer has done its job adequately, and has relied on the previous layers reputation, rather than scrutiny of the work undertaken," explained Professor Keen.

    “Pension funds rely upon consultants because of their reputation in the field; consultants rely upon academic economists, because their papers had passed academic refereeing,” he added.

    “The final impact is a series of flawed economic assumptions informing pensions’ decision making.”
    SHEFIK
    SHEFIK --- ---
    TADEAS: realclimate se k tomu taky rozepsali:

    RealClimate: New study suggests the Atlantic overturning circulation AMOC “is on tipping course”
    https://www.realclimate.org/index.php/archives/2024/02/new-study-suggests-the-atlantic-overturning-circulation-amoc-is-on-tipping-course/

    The new study by van Westen et al. is a major advance in AMOC stability science, coming from what I consider the world’s leading research hub for AMOC stability studies, in Utrecht/Holland.
    ...
    The paper results from a major computational effort, based on running a state-of-the-art climate model (the CESM model with horizontal resolution 1° for the ocean/sea ice and 2° for the atmosphere/land component) for 4,400 model years. This took 6 months to run on 1,024 cores at the Dutch national supercomputing facility, the largest system in the Netherlands in terms of high-performance computing.
    ...
    Now this tipping point has been demonstrated for the first time in a state-of-the-art global coupled climate model, crushing the hope that with more model detail and resolution some feedback might prevent an AMOC collapse.
    ...
    “their estimate of the tipping point (2025 to 2095, 95% confidence level) could be accurate.”
    ...
    Most models even have the wrong sign of this important diagnostic, which determines whether the feedback on Atlantic salinity is stabilising or destabilising, and this model bias is a key reason why in my view the IPCC has so far underestimated the risk of an AMOC collapse by relying on these biased climate models.
    ...
    They show how particularly northern Europe from Britain to Scandinavia would suffer devastating impacts, such as a cooling of winter temperatures by between 10 °C and 30 °C occurring within a century, leading to a completely different climate within a decade or two, in line with paleoclimatic evidence about abrupt ocean circulation changes.
    ...
    Given the impacts, the risk of an AMOC collapse is something to be avoided at all cost. As I’ve said before: the issue is not whether we’re sure this is going to happen. The issue is that we need to rule this out at 99.9 % probability. Once we have a definite warning signal it will be too late to do anything about it, given the inertia in the system.
    ...
    ...
    In the reactions to the paper, I see some misunderstand this as an unrealistic model scenario for the future. It is not. This type of experiment is not a future projection at all, but rather done to trace the equilibrium stability curve (that’s the quasi-equlibrium approach mentioned above). In order to trace the equlibrium response, the freshwater input must be ramped up extremely slowly, which is why this experiment uses so much computer time. After the model’s tipping point was found in this way, it was used to identify precursors that could warn us before reaching the tipping point, so-called “early warning signals”. Then, the scientists turned to reanalysis data (observations-based products, shown in Fig. 6 of the paper) to check for an early warning signal. The headline conclusion that the AMOC is „on tipping course“ is based on these data.

    In other words: it’s observational data from the South Atlantic which suggest the AMOC is on tipping course. Not the model simulation, which is just there to get a better understanding of which early warning signals work, and why.
    TADEAS
    TADEAS --- ---
    "kind of scary"

    Atlantic Ocean circulation nearing ‘devastating’ tipping point, study finds | Oceans | The Guardian
    https://www.theguardian.com/environment/2024/feb/09/atlantic-ocean-circulation-nearing-devastating-tipping-point-study-finds

    new paper, published in Science Advances, has broken new ground by looking for warning signs in the salinity levels at the southern extent of the Atlantic Ocean between Cape Town and Buenos Aires. Simulating changes over a period of 2,000 years on computer models of the global climate, it found a slow decline can lead to a sudden collapse over less than 100 years, with calamitous consequences.

    The paper said the results provided a “clear answer” about whether such an abrupt shift was possible: “This is bad news for the climate system and humanity as up till now one could think that Amoc tipping was only a theoretical concept and tipping would disappear as soon as the full climate system, with all its additional feedbacks, was considered.”

    It also mapped some of the consequences of Amoc collapse. Sea levels in the Atlantic would rise by a metre in some regions, inundating many coastal cities. The wet and dry seasons in the Amazon would flip, potentially pushing the already weakened rainforest past its own tipping point. Temperatures around the world would fluctuate far more erratically. The southern hemisphere would become warmer. Europe would cool dramatically and have less rainfall. While this might sound appealing compared with the current heating trend, the changes would hit 10 times faster than now, making adaptation almost impossible.

    ...

    “What surprised us was the rate at which tipping occurs,” said the paper’s lead author, René van Westen, of Utrecht University. “It will be devastating.”

    He said there was not yet enough data to say whether this would occur in the next year or in the coming century, but when it happens, the changes are irreversible on human timescales.

    In the meantime, the direction of travel is undoubtedly in an alarming direction.

    “We are moving towards it. That is kind of scary,” van Westen said
    TADEAS
    TADEAS --- ---
    TADEAS:

    2023 Is the current methane growth event comparable to a glacial/interglacial Termination event?
    https://meetingorganizer.copernicus.org/EGU23/EGU23-7871.html

    Modelling indicates that, for scale and speed, the biogenic feedback component of methane's growth and isotopic shift in the 16 years from 2006-2022 is comparable to (or greater than) phases of abrupt growth and isotopic shift during glacial/interglacial terminations, from Termination V (about 430 ka BP) to Termination I that initiated the Holocene. These were rapid global-scale climate shifts when the Earth system reorganised from cold glacial to warmer interglacial conditions. Methane's recent 2006-2022 growth in biogenic sources may be within Holocene variability, but it is also a possibility that methane may be providing the first indication that a very large-scale end-of-Holocene reorganisation of the climate system is already under way: Termination Zero.
    TUHO
    TUHO --- ---
    The tropical Pacific Ocean is a key regulator of Earth's climate, with teleconnections that influence remote locations all around the world. Here we use partially coupled climate model experiments to show that tropical Pacific cooling related to an abrupt Atlantic Meridional Overturning Circulation (AMOC) slowdown can strengthen the AMOC by ∼25%. This tropical-extratropical teleconnection occurs initially via atmospheric Rossby waves propagating from the tropical Pacific to the North Atlantic which alter surface climate conditions locally. These changes facilitate ocean heat loss from the subpolar gyre, favoring enhanced oceanic convection. The AMOC strengthening is subsequently enhanced by anomalous northward salt advection in the Atlantic, with a potential contribution from oceanic wave adjustment triggered by increased Southern Ocean westerly winds. These results highlight the influence of the tropical Pacific on the AMOC on multidecadal timescales and suggest that cold phases of tropical Pacific decadal variability could drive temporary strengthening of the AMOC.

    Key Points
    Tropical Pacific cooling can drive a strengthening of the Atlantic Meridional Overturning Circulation (AMOC)

    The Pacific–North Atlantic teleconnection occurs via both atmospheric and oceanic planetary waveguides

    Pacific–AMOC teleconnections can be induced on a multidecadal time-scale

    https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL103250
    TADEAS
    TADEAS --- ---
    Rising methane could be a sign that Earth's climate is part-way through a 'termination-level transition'
    https://theconversation.com/rising-methane-could-be-a-sign-that-earths-climate-is-part-way-through-a-termination-level-transition-211211

    In the past few million years, Earth’s climate has flipped repeatedly between long, cold glacial periods, with ice sheets covering northern Europe and Canada, and shorter warm inter-glacials.

    When each ice age ended, Earth’s surface warmed by as much as several degrees centigrade over a few millennia. Recorded in air bubbles in ice cores, sharply rising methane concentrations are the bellwethers of these great climate-warming events. With each flip from a glacial to an interglacial climate there have been sudden, sharp rises in atmospheric methane, likely from expanding tropical wetlands.

    These great climate flips that ended each ice age are known as terminations. Each has a Roman numeral, ranging from Termination IX which happened about 800,000 years ago to Termination IA which initiated the modern climate less than 12,000 years ago. For example, around 131,000 years ago during Termination II, the British climate suddenly flipped from glaciers in the Cotswolds to hippopotami wallowing in what is now Trafalgar Square.

    Full terminations take several thousands of years to complete, but many include a creeping onset of warming, then a very abrupt phase of extremely rapid climate change that can take a century or less, followed by a longer, slower period during which the great ice caps finally melt. In the abrupt phase of the great change that brought about the modern climate, Greenland’s temperature rose by around 10°C within a few decades. During these abrupt phases, methane climbs very steeply indeed.

    ...

    Methane fluctuated widely in pre-industrial times. But its increasingly rapid growth since 2006 is comparable with records of methane from the early years of abrupt phases of past termination events, like the one that warmed Greenland so dramatically less than 12,000 years ago.

    There is already lots of evidence that the climate is shifting. Atlantic ocean currents are slowing, tropical weather regions are expanding, the far north and south are warming fast, ocean heat is breaking records and extreme weather is becoming routine.

    In glacial terminations, the entire climate system reorganises. In the past, this took Earth out of stable ice age climates and into warm inter-glacials. But we are already in a warm interglacial. What comes next is hard to imagine: loss of sea ice in the Arctic in summer, thinning or partial collapse of the ice caps in Greenland and West Antarctica, reorganisation of the Atlantic’s ocean currents and the poleward expansion of tropical weather circulation patterns. The consequences, both for the biosphere in general and food production in south and east Asia and parts of Africa in particular, would be very significant
    TUHO
    TUHO --- ---
    TUHO: zajimavy

    People tend to have a limited trust of computer models, and quite rightly so. The computer models are not completely trustworthy, as the modelers themselves are aware. Unfortunately, we have no other choice. It would be difficult to make predictions, almost impossible, without computer models, so we simply have to take the real scientific risk that the models are far from perfect.
    For example, the models are deliberately designed to be stable. You can't do anything with an unstable model, and therefore by design they're incapable of showing any horrible, abrupt, very unlikely, but totally catastrophic thing that might happen. They're just not able to show those things.
    Then there's the public relations risk. People would like to have it all written down, and if you're an engineer, you'd like to have the basic equations that prove that it's going to get three degrees warmer. Models just can't provide that, so people are suspicious.
    TADEAS
    TADEAS --- ---
    The Coming Tsunami of Grief | Kevin Hester
    https://kevinhester.live/2017/01/20/the-coming-tsunami-of-grief/

    As runaway abrupt climate change and it’s brutal reality bares down on us with the speed of a tsunami, another little discussed side affect is grief. I shall try to cover it in this blog and provide some avenues for readers to seek solace and solidarity below.
    TUHO
    TUHO --- ---
    Climate change, ecosystems and abrupt change: science priorities

    Ecologists have long studied patterns, directions and tempos of change, but there is a pressing need to extend current understanding to empirical observations of abrupt changes as climate warming accelerates. Abrupt changes in ecological systems (ACES)—changes that are fast in time or fast relative to their drivers—are ubiquitous and increasing in frequency. Powerful theoretical frameworks exist, yet applications in real-world landscapes to detect, explain and anticipate ACES have lagged. We highlight five insights emerging from empirical studies of ACES across diverse ecosystems: (i) ecological systems show ACES in some dimensions but not others; (ii) climate extremes may be more important than mean climate in generating ACES; (iii) interactions among multiple drivers often produce ACES; (iv) contingencies, such as ecological memory, frequency and sequence of disturbances, and spatial context are important; and (v) tipping points are often (but not always) associated with ACES. We suggest research priorities to advance understanding of ACES in the face of climate change. Progress in understanding ACES requires strong integration of scientific approaches (theory, observations, experiments and process-based models) and high-quality empirical data drawn from a diverse array of ecosystems

    https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0105
    TUHO
    TUHO --- ---
    TUHO: V prednasce je i odkaz na sbornik, ktery se problematikou zabyva. Pokud mate nekdo tip na aktualnejsi literaturu, budu rad za ne rad .]

    Abrupt Impacts of Climate Change: Anticipating Surprises |The National Academies Press
    https://nap.nationalacademies.org/catalog/18373/abrupt-impacts-of-climate-change-anticipating-surprises
    TUHO
    TUHO --- ---
    Skvela starsi prednaska o nahlych zmenach klimatu od Jamese Whitea. Aneb to co jsme videli doted, je pravdepodobne nic oproti tomu, co prichazi. Dobry je to zvlast pro milovniky cernyho humoru, kterym prednasejici nesetri .]]

    #abrupt climate change

    Abrupt Climate Change: Past, Present, and Future
    https://www.youtube.com/watch?v=hZdhPnsp4Is


    James White
    James W. C. White | Institute of Arctic and Alpine Research | University of Colorado Boulder
    https://www.colorado.edu/instaar/james-w-c-white
    TUHO
    TUHO --- ---
    Abrupt Climate Change
    Richard B. Alley
    Winter temperatures plummeting six degrees Celsius and sudden droughts scorching farmland around the globe are not just the stuff of scary movies. Such striking climate jumps have happened before—sometimes within a matter of years

    Sci-Hub | Abrupt Climate Change. Scientific American, 291(5), 62–69 | 10.1038/scientificamerican1104-62
    https://sci-hub.se/10.1038/scientificamerican1104-62

    PER2
    PER2 --- ---
    https://www.sciencedirect.com/science/article/abs/pii/S0277379122005522

    This study is a clear demonstration that both extreme orbital conditions and the change of the Earth's magnetic field could cause abrupt climate and environmental changes.
    PER2
    PER2 --- ---
    make the ice age great again
    Abrupt global ocean circulation collapse. Time to start prepping?
    https://youtu.be/j2ETr6X1lOk
    PER2
    PER2 --- ---
    Inside the Experiment: Abrupt Change and Ice Cores
    https://youtu.be/sKR3e0fhiKQ
    TADEAS
    TADEAS --- ---
    https://twitter.com/jrockstrom/status/1584811163329523712?s=19
    PER2
    PER2 --- ---
    TUHO: nehodlam se tu s tebou tocit na grafech (vadi mi osekavani grafu z obou taboru) a urcovani svetovy prumerny teploty z ruznych proxies je taky pekna vec na delsi debatu

    na konec snad jen:
    "How fast can our planet’s climate change? Too slowly for humans to notice, according to the firm belief of most scientists through much of the 20th century. Any shift of weather patterns, even the Dust Bowl droughts that devastated the Great Plains in the 1930s, was seen as a temporary local excursion. To be sure, the entire world climate could change radically: The ice ages proved that. But common sense held that such transformations could only creep in over tens of thousands of years.
    In the 1950s, a few scientists found evidence that some of the great climate shifts in the past had taken only a few thousand years. During the 1960s and 1970s, other lines of research made it plausible that the global climate could shift radically within a few hundred years. In the 1980s and 1990s, further studies reduced the scale to the span of a single century. Today, there is evidence that severe change can take less than a decade. A committee of the National Academy of Sciences (NAS) has called this reorientation in the thinking of scientists a veritable “paradigm shift.” The new paradigm of abrupt global climate change, the committee reported in 2002, “has been well established by research over the last decade, but this new thinking is little known and scarcely appreciated in the wider community of natural and social scientists and policymakers.”"
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