Latest news with #marineheatwaves
Yahoo
4 days ago
- Science
- Yahoo
Marine heatwaves may have driven the world's oceans to a critical tipping point, scientists warn
In 2023, the Earth experienced an unprecedented surge in marine heatwaves across its oceans. They set new records in intensity, geographic extent, and duration, with many lasting well over a year and 96 per cent of the ocean surface affected. Following new research, scientists now warn that these prolonged temperature spikes might herald a tipping point for the world's oceans with grave consequences for the planet. Earth's oceans may have undergone a fundamental shift In 2023, heatwaves resulted in both the North Atlantic and Southwest Pacific oceans experiencing record-breaking sea surface temperatures. 'We know that marine heatwaves have become increasingly common and more intense over time because of global warming. We also know that the El Niño that kicked off in 2023 allowed more heat to enter the ocean,' says climate research scientist Alex Sen Gupta from the University of New South Wales. 'But these factors alone can't explain the incredible scale of the jump that began in 2023.' Scientists from China, the USA and Thailand decided to investigate what was behind the extreme warming and what ramifications it has and could have in the future. Related Heatwaves in Europe: Which countries face the biggest GDP and labour productivity losses? Sea temperature in Portugal's Algarve reaches record highs as 'marine heatwave' hits The research found that reduced cloud cover, which allows more solar radiation to reach the water, was a key driver, alongside weaker winds that diminish cooling from evaporation, and changing ocean currents. While the paper doesn't explain why these influences coincided to smash temperature records, it highlights why it is critical to dedicate more research to the mechanics of ocean warming. The study voices scientists' fears that the Earth's oceans have undergone a fundamental shift, transitioning to a new, hotter state that they say is now the 'new normal'. Author Zhenzhong Zeng, from the Southern University of Science and Technology in China, said figures suggest heat in the world's oceans is accumulating exponentially. If this is indeed the case, it is a trend that would go against what current climate models have projected. Ocean warming has devastating effects on marine ecosystems and life on land The study also warns that the oceans' shift to a permanently warmer state could have devastating effects for life on Earth. This is because they play a central role in regulating global temperatures by storing and slowly releasing large amounts of heat. Because the oceans take more time to react to changes than the atmosphere, the effects of heatwaves can be both delayed and dramatic. This includes hampering the ability to predict short-term extreme weather events, such as hurricanes, and longer-term climatic changes. Related How your old phone could become a 'tiny data centre' helping researchers to track marine life Lost income, less tourists and freak weather: Overheated seas affect far more than just marine life Prolonged increased water temperatures would also be catastrophic for marine ecosystems, triggering mass die-offs or migrations of species. It also increases the chances of coral reef collapse - a concern not least because the loss of coral hinders the ocean's ability to sequester carbon, leading to more heating. On land, it would mean accelerated warming, as sea breezes carry hot air inland. This can cause more intense and widespread droughts, heatwaves, wildfires and storms. This was already evidenced by Storm Daniel in 2023, which killed nearly 6,000 people. Attribution studies found that it was made 50 times more likely and 50 per cent more intense by high sea surface temperatures in the Mediterranean. Are marine heatwaves becoming the new normal? The findings are particularly worrying given the subsequent heatwaves in 2024 and 2025 that boiled oceans around the world. This year, sea surface temperatures in the Mediterranean reached their highest level ever recorded for June. On 29 June, sea surface temperatures hit 26.01°C, according to data collected by Copernicus and analysed by Météo-France. Overall temperatures were 3-4°C higher than average. It sparked fresh warnings from marine scientists of the devastating impacts on biodiversity, fisheries, aquaculture, and weather patterns across southern Europe and North Africa. Related Climate change tripled death toll of latest European heatwave, first ever rapid study finds Heatwaves, floods and sea level rise: UK weather extremes are increasing, Met Office confirms In May, a marine heatwave hit the UK, a place where surges in sea surface temperatures are still a relatively new phenomenon. Parts of the North Sea, English Channel and Irish coast were as much as 4°C warmer than average. Scientists say an exceptionally warm, dry spring coupled with weak winds allowed heat to build on the ocean's surface. They warned the flare-up could disrupt marine ecosystems, altering breeding cycles, enabling blooms of harmful algae or attracting jellyfish that thrive in warmer waters. 'It is critical that we continue to measure, monitor and model the future of our Earth' A fundamental shift in ocean dynamics that defies current climate models is an alarming prospect. Some researchers have responded that the warning is premature. 'We don't know what's going to happen next year, and it [ocean temperatures] might just come back to something that's much more, let's say, normal,' Neil Holbrook, climate scientist at the University of Tasmania in Australia, told the New Scientist, adding that current research can only draw on a few years of data. But even so, scientists back the paper's exhortation to study the drivers of ocean warming. 'While we urgently need to reduce our GHG emissions, it is critical that we also continue to measure, monitor and model what our future Earth is going to be like,' says Jaci Brown, Climate Lead at Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO). 'If we don't, we can't prepare, and we are walking into the unknown with dire consequences for our future food, health and security.'
Yahoo
24-07-2025
- Climate
- Yahoo
500km Australian toxic crisis triggers release of seven-point plan: 'Nowhere is safe'
As the worst Australian algal bloom in recorded history continues to kill almost everything in its path across 500km of coastline, the nation's top experts have released a seven-point plan to deal with the problem. With extreme events like this expected to occur not just in South Australia but around the country as climate change worsens, the Biodiversity Council – an independent expert group founded by 11 universities – has created a plan to protect tourism and fishing jobs as well as the environment. One of the plan's authors, Dr Scott Bennet, from the University of Tasmania Institute of Marine and Antarctic Studies, warned that 'sadly, nowhere is safe' from marine heatwaves. 'We don't see this as an isolated event. This is symptomatic of broader climate change and marine heatwave impacts that are happening around the country,' he told Yahoo News. 'Until this event, South Australia had been relatively immune, and it was an area of least concern. All the ingredients are in these other places for similar events to happen, and they have happened on the east and west coasts, just at a smaller scale.' What is the seven-point plan? The seven-point plan is contained within a new report, Key actions needed to respond to South Australia's catastrophic toxic algal bloom, and the recommendations are: 1. Investigate and fast-track emergency interventions for species at high risk of extinction or major population declines. 2. Immediately invest a minimum of $10 million to start research to understand the impact of this bloom and inform plans for what to do when the next bloom hits. 3. Accelerate Australia's decarbonisation efforts and become a global leader in climate action. 4. Reduce nutrient and dissolved carbon pollution. 5. Restore and protect marine ecosystems. 6. Establish a long-term monitoring program for the Great Southern Reef 7. Establish mechanisms to plan for and respond to catastrophic natural disasters Key sign algal bloom is now fuelling itself The scale of the karenia mikimotoi algal bloom is associated with events linked to climate change. The first was the flooding of the Murray River, which resulted in nutrient-rich water entering the Southern Ocean in 2022/2023. The second was a cold upswelling that drew this runoff to the surface. And the third was a marine heatwave that began in September, 2024. It was in March, 2025 that dying fish began to be documented, and a group of beachgoers reported feeling sick. Since then, more than 14,000 observations of dead marine species have been recorded, and 450 species have been impacted. Some, like the giant cuttlefish and leafy seadragon, have restricted ranges, and their long-term future is in doubt. 'We did initial surveys at a couple of sites that were known as good "leafy" sites, but we didn't see any,' Bennett said. 'They're only found in southern Australia, so if we lose these local populations, that's most of the species' distribution. And once they're gone, they're gone, we can't bring them back.' The problem is greatest when you look under the surface of the ocean, as report author and Biodiversity Council member Professor Gretta Pecl explained. 'Looking at the footage under the water, it's absolute devastation. What's turning up on beaches in South Australia is only the tip of the iceberg. There are dead bodies lying everywhere, decaying,' she said. Bennett added that because everything across the ecosystem has been impacted, there's nothing to feed on the bodies of dead organisms. 'There's an idea now that the bloom is fueling itself… the dead stuff is just decomposing, and all those nutrients are then recycling back into the system,' he said. It had been hoped the problem would dissipate over winter as the air temperature cooled, but this has not occurred. Now the winter solstice has passed, and the weather is warming again. Calls for Albanese Government to declare a disaster While the Albanese Government has committed $14 million to help South Australia respond to the problem, Environment Minister Murray Watt has said he's not able to officially declare the situation a Natural Disaster. The Malinauskas state government has connected the bloom to climate change and voiced concerns the problem will occur again. It is understood to have spoken to the Commonwealth about updating the 2018 Disaster Recovery Funding Arrangements, so future blooms can be declared Natural Disasters like floods or bushfires, streamlining the process for securing federal funding. Greens senator Sarah Hanson-Young has called for the Albanese Government to declare the situation a 'national disaster', referencing the National Emergency Declaration laws that were introduced in 2020. This was activated once before in 2022, when flooding along Australia's east coast killed 26 people and displaced thousands. It would need to be declared by the Governor General at the request of the Prime Minister, and it would open up significant emergency management resources to tackle the problem. Yahoo has asked Minister Watt's office if he has broached this idea with Albanese, but it has yet to respond. In a statement, a Commonwealth government spokesperson said the response was the 'primary responsibility' of the South Australian government, but it would support its efforts. 'The health and resilience of Australia's ocean is a high priority for the Albanese Government. We are deeply concerned by the widespread marine species mortalities caused by this extreme event,' it said. Marine heatwave bigger than South Australia Pecl, who is also a professor at the University of Tasmania, said she believes the response from government should match the scale of the impact and the risk. 'For example, when we had the massive Black Summer bushfires, there was $2 billion in the national bushfire recovery fund, including a $200 million response for wildlife,' she said. The marine heatwave isn't just isolated to South Australia, the problem has been detected all around Australia's coastline, killing up to 80 per cent of corals in one surveyed region in Western Australia, and bleaching reefs on the east coast at the same time. 'Scientists have been banging on about this for 30 years now, so it's not a surprise to us. These patterns are entirely consistent with what we thought would happen. They are a very strong indication of exactly the magnitude of the challenges we'll face in the future,' Pecl said. Addressing whether Australia is doing enough to slow climate change, her response was blunt. 'I can conclusively say that whatever we're doing is not enough,' she said. 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Yahoo
28-06-2025
- Climate
- Yahoo
Mediterranean Sea poised to break all-time heat records
ROME – The Mediterranean Sea is on track to potentially surpass its all-time highest recorded temperature, with large portions of the basin estimated to be between 5- and 10-degrees Fahrenheit above average, with even locally greater anomalies. According to satellite data, sea surface temperatures throughout the region have been consistently breaking records through the month of June. Most readings are registering in the mid to upper 70s Fahrenheit, and with the hottest months of the season still to come, there appears to be little in store to immediately reverse the warming trend. The warmest average sea surface temperature for the Mediterranean was set just last year, when the basin reached a stunning 84 degrees Fahrenheit in August 2024, surpassing the previous record set in 2023, according to Europe's Copernicus Marine Service. Alaska's Largest Wildfires Of Year Rage After 31,000 Lightning Strikes Over 3-Day Period Extended marine heatwaves are known to damage coral reef ecosystems, and while the Mediterranean Sea does not have extensive reefs compared to the tropics, biologists say it is home to unique coral formations and other marine habitats. In addition to ecological risks, the warming sea surface is influencing weather patterns across Southern Europe and Northern Africa. Weather observation sites have recorded elevated dew points in recent days, with some areas reaching the mid-70s Fahrenheit - levels of humidity typically seen in more tropical climates such as the United States' Gulf Coast. This level of added moisture can dramatically increase the heat index and make it harder for the human body to cool down through evaporation. Studies estimate that just over 20% of households across Europe have access to air conditioning, which can make any heat wave oppressive. Elevated sea surface temperatures in the Mediterranean are not just an isolated phenomenon - it is part of a larger global trend, with record warmth observed in most ocean basins over the past few years. Many climatologists attribute the long-term warming to climate change, while others point to more regional oscillation patterns as contributing factors. 2025 Atlantic Hurricane Season Guide: Here's What To Know About The Tropics This Year At face value, a persistently warm subtropical zone, such as the current Mediterranean setup and nearby waterways, can suppress tropical cyclone formation in the Main Development Region (MDR) of the Atlantic by decreasing atmospheric instability. At the same time, it can also lead to tropical activity in more unusual northern latitudes, outside the classic storm formation zones. Forecasters will be watching closely to see whether the current anomalies in the Mediterranean Sea migrate more southwestward, which could align with more traditional water temperature patterns. A similar setup occurred in 2003, when a boiling Mediterranean was paired with a more lukewarm tropical Atlantic early in the season, but sea temperatures eventually transitioned weeks later, warming the MDR and leading to several long-track Cape Verde hurricanes. Whether the 2025 hurricane season follows a similar pattern remains to be seen, but the impacts of the latest Mediterranean heat wave will be monitored for impacts locally and around the article source: Mediterranean Sea poised to break all-time heat records
Japan Times
18-06-2025
- Science
- Japan Times
Marine heat waves are spreading around the world
In recent decades, the oceans have warmed. Marine heat waves, once rare events, have become more common. One particularly intense event known as "the Blob' lasted years and devastated plankton populations, starving millions of fish and seabirds and damaging commercial fishing. Recently, high temperatures have persisted. In January 2024, the share of the ocean surface experiencing a heat wave topped 40%. Unusual heat waves have occurred in all of the major ocean basins around the planet in recent years. And some of these events have become so intense that scientists have coined a new term: super marine heat waves. "The marine ecosystems where the super marine heat waves occur have never experienced such a high sea surface temperature in the past,' Boyin Huang, an oceanographer at the National Oceanic and Atmospheric Administration, said in an email. The seas off the coasts of the United Kingdom and Ireland experienced an unusually intense marine heat wave, one of the longest on record, starting in April, and the temperature rise happened much earlier in the year than usual. Australia and its iconic coral reefs were recently struck by heat waves on two coasts. Scientists define marine heat waves in different ways. But it's clear that as the planet's climate changes, the oceans are being fundamentally altered as they absorb excess heat trapped in the atmosphere from greenhouse gases, which are emitted when fossil fuels are burned. Hotter oceans are causing drastic changes to marine life, sea levels and weather patterns. Some of the most visible casualties of ocean warming have been coral reefs. When ocean temperatures rise too much, corals can bleach and die. About 84% of reefs worldwide experienced bleaching-level heat stress at some point between January 2023 and March 2025, according to a recent report. Last year, the warmest on record, sea levels rose faster than scientists expected. Research showed that most of that rise in sea levels came from ocean water expanding as it warms, which is known as thermal expansion, not from melting glaciers and ice sheets, which in past years were the biggest contributors to rising seas. In a photo from the National Park Service, a humpback whale named Festus that was found dead just outside the mouth of Glacier Bay, Alaska, June 2016. A report on this whale revealed numerous health conditions, including poor nutrition and elevated levels of harmful algal toxins. | Craig Murdoch / National Park Service, NOAA permit #18786 / via The New York Times Excess heat in the oceans can also affect weather patterns, making hurricanes more likely to rapidly intensify and become more destructive. In the southwest Pacific, last year's ocean heat contributed to a record-breaking streak of tropical cyclones hitting the Philippines. "If we understand how global warming is affecting extreme events, that is essential information to try to anticipate what's going on, what's next,' said Marta Marcos, a physicist at the University of the Balearic Islands in Spain. Marcos was the lead author of a recent study published in Proceedings of the National Academy of Sciences that found that climate change has been responsible for the overwhelming majority of marine heat waves in recent decades. The losses Some of the earliest research on mass die-offs associated with marine heat waves, before there was a name for them, came from the Mediterranean, which has been warming three to five times faster than the ocean at large. Joaquim Garrabou, a marine conservation ecologist at the Institut de Ciencies del Mar in Barcelona, Spain, started studying these events after witnessing a die-off of sponges and coral in 1999. He and other scientists believed that with climate change, these die-offs would reoccur. "The reality is moving even faster than what we thought,' he said. "Having these mass mortality events is the new normal, instead of something infrequent, which it should be.' In 2012, a marine heat wave in the Gulf of Maine highlighted the risk these events pose to fisheries. The Northern shrimp population went from an estimated 27.25 billion in 2010 to 2.8 billion two years later, according to modeling by the Atlantic States Marine Fisheries Commission. "This disappearance of the shrimp was just shocking,' said Anne Richards, a retired research fisheries biologist who worked at NOAA's Northeast Fisheries Science Center at the time. In a photo from Jemina Stuart-Smith, University of Tasmania, a red handfish is collected in the waters off the coast of Tasmania. In a heatwave that began in 2023, researchers in Tasmania transferred 25 red handfish to an aquarium until the temperatures fell. | Jemina Stuart-Smith, University of Tasmania / via The New York Times Her research pointed to a significant culprit: Longfin squid drawn north by warmer water were eating the shrimp. The fishery has not yet reopened. By 2023, the Northern shrimp population was estimated to have dropped to around 200 million. Commercial fishing has always been difficult, but now, "climate change is taking that to another level,' said Kathy Mills, a senior scientist at the Gulf of Maine Research Institute. Complicating matters is the fact that much of the research on marine heat waves comes from just a few countries, including Australia, the United States, China, Canada, Spain and the United Kingdom. "There are lots of regions around the world where monitoring isn't as good as other places, and so we don't really know what's happening,' said Dan Smale, a community ecologist at the United Kingdom's Marine Biological Association. Rising ocean temperatures can also set off a domino effect through the marine food web, starting at the bottom with plankton. In a photo from the Coastal Observation and Seabird Survey Team, emaciated Cassin's auklets found during a single survey on an Oregon beach, on Jan. 8, 2015. During the ocean heat event in the North Pacific known as 'the Blob,' hundreds of thousands of birds died of starvation. | Coastal Observation and Seabird Survey Team / via The New York Times Since the end of most commercial whaling in the 1970s and '80s, humpback whales in the North Pacific had been recovering, reaching a peak population of about 33,000 in 2012. But then came the heat event known as "the Blob' that blanketed much of region from 2014 to 2017. The heat wave diminished wind and waves, limiting the nutrients that typically get churned up to the sea surface. Fewer nutrients meant fewer phytoplankton, fewer zooplankton, fewer fish and fewer of everything else that eats them. How 'the blob' took a toll After the Blob dissipated, researchers learned that the effects of a severe marine heat wave could endure long after the event itself has passed. Ted Cheeseman, a doctoral candidate at Southern Cross University, had co-founded Happywhale, a database of tens of thousands of marine mammals built on photos submitted by researchers and whale watchers around the world. Cheeseman found a sharp drop in humpback whale sightings by 2021. The decrease was so significant, at first he thought the Happywhale team was doing the math wrong. The team members spent several years checking and last year published a study that concluded the humpback whale population in the North Pacific had fallen by 20% from 2012 to 2021. They attributed the decline to the loss of food like krill during and after the Blob. With "an estimate of 7,000 whales having disappeared and not showing up anywhere else,' Cheeseman said, "there's really no other explanation.' Looking ahead Eventually, parts of the ocean might enter a constant state of marine heat wave, at least by today's common definition. Some scientists see today's shorter-term spikes as practice for this future. Alistair Hobday, a biological oceanographer at Australia's Commonwealth Scientific and Industrial Research Organisation, has been conducting public briefings with marine heat wave forecasts months ahead of time. People are tuning in — and responding. In a photo from Jemina Stuart-Smith, University of Tasmania, a red handfish in the waters off the coast of Tasmania. | Jemina Stuart-Smith, University of Tasmania / via The New York Times The critically endangered red handfish lives off the coast of Tasmania, crawling along the seafloor on fins shaped like hands. These unusual fish have only been found within two small patches of rocky reef and sea grass meadow. In late 2023, Hobday's forecast predicted potentially deadly marine heat waves. Researchers from the University of Tasmania's Institute for Marine and Antarctic Studies, with support from the Australian Department of Climate Change, took a drastic step. They transferred 25 red handfish to an aquarium until the temperatures fell. Jemina Stuart-Smith, an ecologist at the University of Tasmania, described those weeks as the most stressful time of her life. "If it all went wrong,' she said, "you're talking about the potential extinction of an entire species.' After three months, 18 fish were returned to the ocean. Three had died, and four were enrolled in a captive breeding program. Scientists recognize that temporary fixes can only do so much in the face of long-term warming. "It's kind of putting a Band-Aid on a broken leg,' said Kathryn Smith, a marine ecologist and postdoctoral researcher at the Marine Biological Association. But those studying today's extreme events still hope their work gives people some visibility into the future of the world's oceans, Hobday said. "Clever people, if you tell them about the future,' he said, "can think of all kinds of things to do differently.' This article originally appeared in The New York Times © 2025 The New York Times Company
The Independent
12-06-2025
- Science
- The Independent
Oceans have absorbed heat of 1.7 billion atomic bombs, scientists warn as UN summit opens in Nice
Oceans have absorbed enough heat since the Paris Agreement was signed to match the energy of 1.7 billion atomic bomb explosions, scientists warned just as the UN Ocean Conference got underway in Nice. The figures were shared by researchers on the sidelines of the summit where delegations from countries were working to create a global treaty for ocean conservation. Scientists said warming was accelerating changes in marine systems, driving sea level rise, sea ice loss, and increasing marine heatwaves. 'Global warming over the last 10 years equates to about 1.7 billion atomic bomb explosions,' said Alex Sen Gupta, associate professor at the University of New South Wales. 'If we divide this by the number of seconds in 10 years, it's equivalent to about five atomic explosions worth of energy every single second. Clearly this is having an effect on the ocean – it is causing the sea level to rise, our ice systems to melt, and our atmosphere and oceans to warm.' As the conference opened on Monday, UN secretary general António Guterres said the world 'must move from plunder to protection to save the oceans'. Among the most serious warnings are new records set for sea surface temperatures this year, an all-time low for global sea ice, and what scientists say is the largest coral bleaching event ever recorded, affecting 84 per cent of monitored reef areas. 'My recent research has shown that marine heatwaves have caused severe impacts globally over the past few years,' said Dr Kathryn E Smith of the Marine Biological Association of the UK. 'We've seen more fisheries collapses, mass mortality events, and damage to ecosystems. The warming oceans have also fuelled storms on land causing billions of dollars in damages and resulting in thousands of deaths. These impacts have all occurred before we have reached the 1.5 C benchmark. A decade on from the Paris Agreement it is clear that it's even more important than ever that we make every effort not to exceed the warming limits agreed in 2015.' The UN Ocean Conference is co-hosted this year by France and Costa Rica, with participation from over 100 countries. It aims to accelerate action to meet global ocean protection targets and finalise voluntary commitments on issues including pollution, overfishing, deep-sea mining and marine biodiversity. France's president Emmanuel Macron said the High Seas Treaty could come into force as early as January 2026. Eighteen countries ratified the treaty during the opening sessions, bringing the total to 49 – just 11 short of the number needed for adoption. Mr Macron also reiterated France's call for a moratorium on deep-sea mining, declaring the "oceans are not for sale". Several experts at the Nice conference said ocean protection must now move from pledges to policies. The conference is expected to issue the 'Nice Ocean Action Plan' and press for the legally binding entry into force of the High Seas Treaty. The UK, which had faced criticism for delays, said it would introduce legislation by the end of the year to ratify the High Seas Treaty. 'Our oceans are dying. Without urgent action, they will be irreversibly destroyed,' marine minister Emma Hardy said. ' Climate change is pushing our ocean into unknown territory, causing collapse and irreparable damage to many valuable ecosystems and marine species,' Dr Karen Filbee-Dexter from the University of Western Australia noted. 'What is most concerning is our emissions have already locked us into impacts that will be felt for generations.' Dr Jennifer Francis, senior scientist at the Woodwell Climate Research Centre, said sea ice loss in the Arctic was one of the clearest indicators of climate disruption. 'During summer, the real estate it covers has diminished by nearly half and its volume by nearly three-quarters in less than a human's lifespan,' she said. 'The loss of ice means ships can now travel more freely along polar routes, with economic benefits but higher risks of fuel spills. Larger areas of open water allow marine algae to proliferate in abnormal ways.' A final political declaration and the Nice Ocean Action Plan are expected at the end of the summit on Friday. Scientists, small island leaders and civil society groups are calling for stronger integration between climate policy and marine conservation efforts. 'Ultimately, the vast majority of ocean impacts that we have seen in the last decade are a result of human induced climate change,' Dr Smith said. 'The escalation of impacts we are seeing is, quite frankly, shocking and without reducing emissions and use of fossil fuels globally, the impacts we see are only going to increase further in coming years.'
