Latest news with #AtlanticMeridionalOverturningCirculation
Yahoo
4 days ago
- Science
- Yahoo
Scientists Are Worried About A Collapse Of This Atlantic Ocean Current: Here's Why
A certain current in the Atlantic Ocean that is essential for temperature regulation is in danger of collapsing. The Atlantic Meridional Overturning Circulation, also known as the AMOC, runs the length of the Atlantic Ocean, including the tip of South America, the Caribbean, and all the way north to Greenland. One of its major benefits is maintaining the European climate by moving warm air from the Equator north. Climatologist and oceanographer at the National Research Center, Sandro Carniel, explained the AMOC's function to Renewable Matter. "This circulation, of which the Gulf Stream is a part, plays the fundamental role of a climate equalizer and is essentially triggered by the weight of water, its density. The colder and saltier the water is, the greater its density, and the easier it is for its mass to sink. Whereas if the water is warm and fresh (i.e., not salty), it is lighter and therefore stays at the surface more." The extreme importance of the AMOC is being threatened by greenhouse gas emissions, a driving force in global warming. Global warming would be a direct contributor to an AMOC collapse. If this is not prevented, the consequences could be catastrophic and include drastic temperature changes, altered weather patterns, and even an ice age event. Read more: This Is How Most Life On Earth Will End Why Would This Atlantic Current Collapse? Global warming is disrupting the way the currents flow due to melting ice caps and glaciers. Carniel continued to explain to Renewable Matter, "The huge amounts of melting ice are pouring an incredible amount of fresh water into the North Atlantic. Less and less salty and warmer waters are helping to lag the general circulation of currents." This is not a new or sudden phenomenon. In 2018, the journal Nature revealed that the buoyancy of the Atlantic Meridional Overturning Circulation had decreased by 15 percent over 70 years. While the AMOC has been affected due to global warming, it has not collapsed yet. To prevent this, greenhouse gas emissions need to be massively reduced. Industrial and manufacturing activities, transportation, and animal agriculture are all driving forces behind large amounts of greenhouse gas emissions. Despite efforts to implement better renewable energy and cleaner practices, the UN claims we are failing at attempts to control climate change. What Would Happen If The AMOC Collapsed? If the AMOC collapsed, European cities would get colder by up to 27 degrees within a few decades. So a temperature of 41 degrees could drop to 14. Comparatively, the Southern Hemisphere would get much warmer. Rising sea levels could send coastal regions underwater and also contribute to increased coastal erosion and more severe storm surges. The impact on weather patterns would be widespread. Europe would experience more violent storms. Major droughts would plague Asia. The changing weather would drastically reduce crop yield, and a full ecosystem collapse could occur across the northern Atlantic. Scientists have a historical reference point for such an event. About 12,900 years ago, the AMOC was halted when Lake Agassiz melted and unleashed massive amounts of freshwater into the sea. It's believed the lake's melting was caused by a comet. The subsequent halt of the AMOC caused over one thousand years of ice age conditions in parts of Europe and North America. Unless we are able to get a handle on global warming and protect the Atlantic Meridional Overturning Circulation, this could be the future we have to prepare for. Read the original article on BGR. Solve the daily Crossword
Buzz Feed
5 days ago
- General
- Buzz Feed
XX Things On The Brink Of Collapse No One Talks About
Between the existential chaos around the world and whatever we're all dealing with in our personal lives, it feels like we're collectively acting like everything is fine these days, but that's not really the case. Political turmoil is wreaking havoc across the globe, climate change is getting realer by the second, and the global economy is shifting, for better or for worse. Needless to say, we're in very trying times, and it feels like burnout is now a universal feeling. A recent post on the r/AskReddit sub asked users the following question: "What is currently on the brink of collapse but no one is talking about it?" From collapsing ecosystems to the rise of AI, these 19 responses highlight just how close our dystopian future might be: Note: these responses have been edited and condensed for clarity. "The orca pod known as J-pod, that are residents of the Pudget Sound, are starving as the salmon population is collapsing." "And to be specific, Chinook salmon. Chinook are their main food source because of the fat content, and they're on the brink of collapse. I mean, it's not looking good for all salmon species, but when/if the Chinook go extinct, that's the first big domino to fall in the Salish Sea ecosystem." "Here in the UK, the water table. Already seen a massive drought in the North with unprecedented lack of rainfall this year. Reservoirs and rivers are lower than they've been in decades. On top of leaking pipes that date back to WWII, we could honestly be talking about real drinking water shortages in 5-10 years." "Honestly, I'd say the internet. Everything requires an account, everything collects your information, you can't own anything because you can only get subscriptions to services. There are way too many social media platforms, which are somehow all owned by the same few mega corporations (Meta, Google, Microsoft, etc.) AI is slowly taking over everything and spewing out misinformation left and right." "Lots of collectively-owned private, professional businesses: Private equity has been relentlessly buying up veterinarian practices, CPA firms, and — I'm sure — all kinds of other businesses so they can egregiously increase prices, sell everything that isn't nailed down, cut staff to nothing, then sell the little bit that's left to some naive future buyer at a hugely inflated cost." "Teachers. Not teaching itself, but the whole system around it. So many teachers are underpaid, overworked, and just done. A lot are quitting quietly or switching careers, and schools are struggling to replace them. It's kind of scary how fast it's unraveling, but no one's really screaming about it yet." "Maybe not on the brink, but possibly approaching — The AMOC, or Atlantic Meridional Overturning Circulation, is a large system of ocean currents that acts like a conveyor belt, circulating warm and cold water throughout the Atlantic Ocean." "Bridges, railroad lines, power grids, and water pipes. Some of them are decades old and unstable (Germany)." "A bunch of small ecosystems around the world." "The working class. Hopefully, the collapse will wake some folks up, but I don't have a lot of hope when they seem perfectly happy in their caves staring at the shadows." "Critical thinking. Humanity is over-reliant on devices and AI to do their thinking for them instead of using tech to enhance their own thinking." "The movie industry feels that way in Hollywood right now." "The Cascadia Subduction Zone." "The 'enrollment cliff' is starting. This year, the lack of kids born during and after the 2008 recession is starting to graduate from high school. In this population pyramid, you can see that starting at the 15-19 age group, birth rates went down and kept going down. Now, it was already going down on average, but right before the recession, there was a small uptick that could have been a turnaround." "Civilizations decline/collapse over generations — I'd suggest that there is a strong possibility that 'the free liberal West' is in the early stages of a multi-generational decline, not unlike that of the Roman empire. Facebook and Netflix are our bread and circuses while around us, cultures that are not compatible with our (democratic, egalitarian, progressive, liberal) values are rising to challenge and eventually displace us. It won't happen in my lifetime, but it is happening." "The Anthropocene." "Overly complex appliances, cars, TVs, etc." "I think our civilization's ability to write without Generative AI. I believe writing is thinking, and it provides clarity to our thoughts. A vast majority of university students are now relying on services like ChatGPT, which I believe will eventually affect us in the long run. I don't have research backing up my claim, and I hope I'm wrong. Regardless, I'm worried." "Surprised I didn't see many posts about insects. We are in a mass extinction event of something like 60% of their population."
Time of India
16-07-2025
- Science
- Time of India
Scientists discover world's largest waterfall — but It's completely invisible, here's why
For decades, the title of the world's tallest waterfall belonged to Venezuela's Angel Falls. But now, scientists are pointing to an even more colossal cascade — one that plunges a staggering 11,500 feet. The twist? It's completely invisible to the human eye. Located deep beneath the ocean's surface between Greenland and Iceland, the Denmark Strait cataract is the largest waterfall on Earth — and no one will ever witness it in person. This underwater marvel moves over 3.2 million cubic meters of water per second, far more than any river on land. Yet its existence remained unknown until scientists began studying ocean temperatures, salinity, and currents in this icy part of the Atlantic. What makes Denmark Strait the world's largest waterfall and why it's invisible The Denmark Strait cataract is an undersea waterfall formed where cold, dense water from the Nordic Sea meets warmer, lighter water from the Irminger Sea. This dramatic temperature and salinity difference causes the heavier water to plunge downward in a massive cascade beneath the ocean surface. First identified through thermal and salinity mapping, this phenomenon doesn't roar or mist like terrestrial waterfalls. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like Indonesia melirik jet tempur J-10 milik China. Mengapa para pakar memperingatkan untuk hati-hati? CNA Indonesia Baca Undo Instead, it silently flows through the darkness, shaped by a submerged ridge left behind by glaciers during the Last Ice Age approximately 11,500 years ago. In sheer height and volume, it surpasses all known waterfalls. Niagara Falls measures about 181 feet, and Angel Falls 3,212 feet, but the Denmark Strait cataract plunges nearly four times deeper. Its hidden nature makes it one of the most fascinating and powerful forces in Earth's ocean systems. A hidden force that regulates Earth's climate Beyond its jaw-dropping size, the Denmark Strait cataract plays a critical role in maintaining global climate stability. As the cold Arctic water descends into the Atlantic, it powers the Atlantic Meridional Overturning Circulation (AMOC), a massive oceanic conveyor belt that distributes heat and nutrients across the world's oceans. This deep-sea flow moderates temperatures in Europe, sustains marine biodiversity, and drives large-scale weather patterns. But the system is fragile. Climate change and warming Arctic waters are threatening the delicate balance of temperature and salinity that keeps this waterfall flowing. A disruption could weaken AMOC, raising ocean temperatures, intensifying hurricanes, and shifting climate zones worldwide. Marine scientists already see early signs of impact, such as the weakening of winter winds along the Catalan coast. Out of sight, yet incredibly influential, the world's largest waterfall is a silent engine behind the rhythms of Earth's climate.
Otago Daily Times
08-07-2025
- Science
- Otago Daily Times
'Unprecedented' changes around Antarctic
By Eloise Gibson of RNZ Researchers have found evidence of a major shift in the circulation of the Southern Ocean which could accelerate climate change for the whole planet. They say the finding has caught them off-guard and that the sea ice around Antarctica could be in "terminal decline". The study, led by the University of Southampton in the United Kingdom and helped by Spanish and other European researchers, found evidence of a change which has shocked other researchers, and which could explain the region's rapid loss of sea ice. The authors say the circulation of the Southern Ocean has reversed. Typically, as global heating melts the ice around Antarctica, climate scientists would expect saltier water at the surface of the ocean to be replaced by fresh water, because melting ice typically makes the ocean fresher. But new satellite data shows the opposite is happening. Because salt water draws up heat from the deep ocean and makes it harder for sea ice to regrow - as well as bringing up carbon dioxide from the depths - a reversal could accelerate ice loss and global heating. The authors - who published their findings in the peer-reviewed journal PNAS - say their salt content measurements "can now provide a coherent explanation for the rapid Antarctic sea ice loss that had puzzled the scientific community". However, the consequences are potentially disruptive for the planet. They say the Southern Ocean plays an essential role in regulating the Earth's heat and carbon and its disruption could trigger cascading effects on other ocean circulation systems, with potential consequences as far away as Europe. "We are witnessing a true change in ocean properties in the Southern Hemisphere - something we've never seen before," said Antonio Turiel, co-author of the study, published by the Spanish marine research institute Institut de Ciències del Mar. "While the world is debating the potential collapse of the AMOC (Atlantic Meridional Overturning Circulation) in the North Atlantic, we're seeing that the Southern Ocean is drastically changing, as sea ice coverage declines and the upper ocean is becoming saltier. This could have unprecedented global climate impacts." "What we found was astonishing," said co-author Alessandro Silvano, an oceanographer at University of Southampton in a piece for The Conversation. "By combining satellite observations with data from underwater robots, we built a 15-year picture of changes in ocean salinity, temperature and sea ice," he said. "Around 2015, surface salinity in the Southern Ocean began rising sharply - just as sea ice extent started to crash. This reversal was completely unexpected." The fleet of underwater robots used in the study are Argo floats, many of them deployed by New Zealand scientists, which drift with ocean currents and return data that any scientist can use. More work urgently needed: NZ researchers The new paper does not explain why the reversal is happening, and New Zealand scientists say more work is urgently needed to complete the puzzle. For decades, the surface of the Southern Ocean was getting fresher and colder, helping sea ice expand - seemingly in defiance of global heating. At the same time, sea ice in the Arctic at the opposite pole was in freefall. Now Antarctic sea ice is also shrinking, contributing to a feedback loop where larger areas of darker open ocean reflect less of the sun's heat back than ice would have - further increasing the heating and melting. Professor Wolfgang Rack, a glaciologist at University of Canterbury and Director of Gateway Antarctica, said the growth of sea ice in the Southern Ocean was seen as climate paradox until it stopped around 2015. "Many scientists expected the trend to reverse at some point, but the rate of the current retreat is completely unexpected and mind boggling," he said. He said the ocean south of Wellington was the "most under-surveyed region globally" and more and urgent work was needed. Associate Professor Inga Smith, a sea ice physicist at the University of Otago, said the new results were "shocking" for those researching Antarctic sea ice. "In a warming world, fresher water from melting of land-based ice sheets and floating ice shelves would be expected to dominate at the ocean surface." Instead, the ocean surface was getting warmer and more salty right at the time the extent of the sea ice shrank. She said although the paper didn't explore why, "the authors will no doubt explore this in a longer paper sometime soon". Dr Ken Hughes, a senior lecturer in coastal processes at the University of Waikato, says when he first began research in 2012 scientists assumed that the ocean and big ice shelves buffered the Antarctic system in some way so that the warming climate was not wrecking havoc on the ice extent in the same way it was for the Arctic. That security could no longer be taken for granted, he said, and the most difficult question was whether the decline would continue. Professor James Renwick, a climate scientist at Victoria University of Wellington, said other research had shown how upper-ocean heat content and westerly winds were changing in the Southern Ocean. The new paper provided more evidence that climate change was causing a "major change" in the way the ocean was working, he said. "The implications are very worrying. "Antarctic sea ice extent will likely continue to trend downwards from here (with ups and downs from year to year). That will accelerate the melting of ice shelves and land-based ice, increasing the rate of sea level rise and pushing us closer to the irreversible loss of the West Antarctic ice sheet. It will also reduce the reflectivity of the planet, bringing more warming." Natalie Robinson, a marine physicist at Earth Sciences New Zealand (formerly NIWA) and associate professor at Victoria University, said despite covering only 17% of the planet, the Southern Ocean was a critical player in the global climate. The annual cycle of sea ice forming and shrinking was a major player in stabilising the climate, especially for New Zealand. "We are moving into uncharted climate territory," she said. "What happens in Antarctica has implications for the entire globe, but here in New Zealand we are impacted by changes to Antarctic sea ice more directly than most. "Early indications are that a warmer Southern Ocean, exacerbated by retreat of the sea ice edge, contributes to increased storminess for New Zealand. "When combined with the steadily warming waters of New Zealand's Exclusive Economic Zone, we should expect to see more of the intense rainfall events we've experienced recently, since warmer air can hold more moisture. "In order to secure a liveable future for ourselves and our children, it is imperative that we drastically reduce our reliance on fossil fuels."
Otago Daily Times
08-07-2025
- Science
- Otago Daily Times
Warning Southern Ocean changes will affect planet
By Eloise Gibson of RNZ Researchers have found evidence of a major shift in the circulation of the Southern Ocean which could accelerate climate change for the whole planet. They say the finding has caught them off-guard and that the sea ice around Antarctica could be in "terminal decline". The study, led by the University of Southampton in the United Kingdom and helped by Spanish and other European researchers, found evidence of a change which has shocked other researchers, and which could explain the region's rapid loss of sea ice. The authors say the circulation of the Southern Ocean has reversed. Typically, as global heating melts the ice around Antarctica, climate scientists would expect saltier water at the surface of the ocean to be replaced by fresh water, because melting ice typically makes the ocean fresher. But new satellite data shows the opposite is happening. Because salt water draws up heat from the deep ocean and makes it harder for sea ice to regrow - as well as bringing up carbon dioxide from the depths - a reversal could accelerate ice loss and global heating. The authors - who published their findings in the peer-reviewed journal PNAS - say their salt content measurements "can now provide a coherent explanation for the rapid Antarctic sea ice loss that had puzzled the scientific community". However, the consequences are potentially disruptive for the planet. They say the Southern Ocean plays an essential role in regulating the Earth's heat and carbon and its disruption could trigger cascading effects on other ocean circulation systems, with potential consequences as far away as Europe. "We are witnessing a true change in ocean properties in the Southern Hemisphere - something we've never seen before," said Antonio Turiel, co-author of the study, published by the Spanish marine research institute Institut de Ciències del Mar. "While the world is debating the potential collapse of the AMOC (Atlantic Meridional Overturning Circulation) in the North Atlantic, we're seeing that the Southern Ocean is drastically changing, as sea ice coverage declines and the upper ocean is becoming saltier. This could have unprecedented global climate impacts." "What we found was astonishing," said co-author Alessandro Silvano, an oceanographer at University of Southampton in a piece for The Conversation. "By combining satellite observations with data from underwater robots, we built a 15-year picture of changes in ocean salinity, temperature and sea ice," he said. "Around 2015, surface salinity in the Southern Ocean began rising sharply - just as sea ice extent started to crash. This reversal was completely unexpected." The fleet of underwater robots used in the study are Argo floats, many of them deployed by New Zealand scientists, which drift with ocean currents and return data that any scientist can use. More work urgently needed: NZ researchers The new paper does not explain why the reversal is happening, and New Zealand scientists say more work is urgently needed to complete the puzzle. For decades, the surface of the Southern Ocean was getting fresher and colder, helping sea ice expand - seemingly in defiance of global heating. At the same time, sea ice in the Arctic at the opposite pole was in freefall. Now Antarctic sea ice is also shrinking, contributing to a feedback loop where larger areas of darker open ocean reflect less of the sun's heat back than ice would have - further increasing the heating and melting. Professor Wolfgang Rack, a glaciologist at University of Canterbury and Director of Gateway Antarctica, said the growth of sea ice in the Southern Ocean was seen as climate paradox until it stopped around 2015. "Many scientists expected the trend to reverse at some point, but the rate of the current retreat is completely unexpected and mind boggling," he said. He said the ocean south of Wellington was the "most under-surveyed region globally" and more and urgent work was needed. Associate Professor Inga Smith, a sea ice physicist at the University of Otago, said the new results were "shocking" for those researching Antarctic sea ice. "In a warming world, fresher water from melting of land-based ice sheets and floating ice shelves would be expected to dominate at the ocean surface." Instead, the ocean surface was getting warmer and more salty right at the time the extent of the sea ice shrank. She said although the paper didn't explore why, "the authors will no doubt explore this in a longer paper sometime soon". Dr Ken Hughes, a senior lecturer in coastal processes at the University of Waikato, says when he first began research in 2012 scientists assumed that the ocean and big ice shelves buffered the Antarctic system in some way so that the warming climate was not wrecking havoc on the ice extent in the same way it was for the Arctic. That security could no longer be taken for granted, he said, and the most difficult question was whether the decline would continue. Professor James Renwick, a climate scientist at Victoria University of Wellington, said other research had shown how upper-ocean heat content and westerly winds were changing in the Southern Ocean. The new paper provided more evidence that climate change was causing a "major change" in the way the ocean was working, he said. "The implications are very worrying. "Antarctic sea ice extent will likely continue to trend downwards from here (with ups and downs from year to year). That will accelerate the melting of ice shelves and land-based ice, increasing the rate of sea level rise and pushing us closer to the irreversible loss of the West Antarctic ice sheet. It will also reduce the reflectivity of the planet, bringing more warming." Natalie Robinson, a marine physicist at Earth Sciences New Zealand (formerly NIWA) and associate professor at Victoria University, said despite covering only 17% of the planet, the Southern Ocean was a critical player in the global climate. The annual cycle of sea ice forming and shrinking was a major player in stabilising the climate, especially for New Zealand. "We are moving into uncharted climate territory," she said. "What happens in Antarctica has implications for the entire globe, but here in New Zealand we are impacted by changes to Antarctic sea ice more directly than most. "Early indications are that a warmer Southern Ocean, exacerbated by retreat of the sea ice edge, contributes to increased storminess for New Zealand. "When combined with the steadily warming waters of New Zealand's Exclusive Economic Zone, we should expect to see more of the intense rainfall events we've experienced recently, since warmer air can hold more moisture. "In order to secure a liveable future for ourselves and our children, it is imperative that we drastically reduce our reliance on fossil fuels."
