Como as águas mais quentes influenciam desde o sumiço das ostras à chegada precoce de baleias no Brazil

by Ana Menezes

 Pesquisadores apontam que o aumento da temperatura do mar já altera a migração de baleias, ameaça cultivos de ostras e impacta a pesca e o litoral catarinense

 

 O mar de Santa Catarina está mudando — e os impactos já começam a aparecer na economia, na biodiversidade e até em símbolos culturais do Estado, como as baleias-francas e as ostras cultivadas em Florianópolis.

 

Nos últimos anos, pesquisadores vêm observando o aumento gradual da temperatura das águas do Atlântico Sul e mudanças importantes no comportamento dos ecossistemas marinhos. Em Santa Catarina, especialistas alertam que os efeitos das mudanças climáticas já atingem a pesca, a maricultura, o turismo, a erosão costeira e os ciclos migratórios de espécies marinhas.

Em 2026, as primeiras baleias-francas chegaram ao litoral catarinense ainda em maio, antecipando novamente a temporada migratória. No mesmo cenário de mudanças no oceano, produtores de ostras enfrentaram perdas expressivas durante o verão devido à mortalidade dos animais provocada por altas temperaturas da água.

 

Pesquisadores apontam que os fenômenos ainda estão em estudo, mas que o aquecimento dos oceanos já provoca alterações perceptíveis na costa catarinense.

O que causou a morte das ostras?

 

Oceano absorve o calor do planeta

A oceanógrafa física e climatologista da Universidade Federal de Santa Catarina (UFSC), Regina Rodrigues, explica que os oceanos absorvem cerca de 90% do excesso de calor gerado pelas atividades humanas.

Segundo ela, estudos com dados de satélite analisados desde 1982 mostram uma tendência contínua de aquecimento no Atlântico Sul, incluindo o litoral de Santa Catarina.

— Estamos vendo cada vez mais períodos em que a temperatura do mar fica muito acima do normal — afirma.

 A pesquisadora explica que o aquecimento global atua junto de mudanças atmosféricas regionais. Entre elas, estão os chamados bloqueios atmosféricos, que reduzem a passagem de frentes frias, deixam o inverno mais seco e aumentam a incidência solar sobre o oceano.

 

— Santa Catarina está entrando mais no clima do Sudeste. Esses bloqueios, que antes eram mais comuns lá, estão se expandindo para o Sul — diz.

Fenômenos como o El Niño podem potencializar esse cenário, já que favorece a formação desses bloqueios atmosféricos e altera os padrões de chuva e temperatura no Sul do Brasil, conforme a pesquisadora.

Procurada pela reportagem, a Defesa Civil de Santa Catarina informou que não é possível afirmar uma relação direta entre o El Niño e o aquecimento das águas na costa catarinense.

Baleias-francas chegam mais cedo ao litoral

Os reflexos dessas mudanças também podem ser percebidos na migração das baleias-francas. A diretora de pesquisa do ProFRANCA, Karina Groch, explica que a chegada antecipada das baleias ao litoral catarinense ainda é estudada, mas que há forte relação entre alimentação, condições oceânicas e comportamento migratório.

 

As baleias-francas vêm para Santa Catarina principalmente para reprodução. As fêmeas chegam grávidas para dar à luz em águas mais abrigadas e permanecem na região até que os filhotes consigam retornar às áreas de alimentação próximas à Antártica.

Segundo Karina, a principal hipótese para a chegada antecipada desses animais envolve a disponibilidade de krill — pequeno crustáceo que serve de alimento para as baleias e depende do gelo antártico para se reproduzir.

— Quando está mais quente, há menos gelo e consequentemente menos krill. Isso influencia toda a cadeia alimentar — explica.

 Pesquisas do ProFRANCA indicam que alterações climáticas na Antártica podem gerar reflexos na população de baleias que chega ao Brasil até seis anos depois. A hipótese é que a espécie mais bem nutrida consegue completar antes o período de alimentação, iniciando a migração mais cedo.

 

— Tudo indica que o momento da chegada delas está relacionado à disponibilidade de alimento e às condições oceânicas — afirma Karina.

Ela ressalta, porém, que ainda são necessários anos de monitoramento para confirmar tendências e entender se a antecipação da temporada está diretamente ligada às mudanças climáticas ou a fenômenos específicos, como o El Niño.

 

Veja fotos das primeiras baleias-francas de 2026 no RS

Ostras sofrem com calor extremo

Enquanto as baleias antecipam a chegada, a maricultura catarinense enfrenta outro desafio: a mortalidade em massa de ostras provocada pelas altas temperaturas da água.

 

Santa Catarina é o maior produtor do marisco do Brasil, especialmente da espécie Magallana gigas, cultivada principalmente em Florianópolis. Mas a espécie, originária do Pacífico, é adaptada a águas mais frias.

Segundo o professor Rafael Diego da Rosa, do Centro de Ciências Biológicas da UFSC e coordenador do Laboratório de Biotecnologia e Saúde Marinha (LaBIOMARIS), o calor extremo registrado no verão provocou perdas expressivas na produção. No início do ano, produtores de ostras de Florianópolis enfrentam uma das maiores crises já registradas na maricultura local. A mortalidade em massa causada pelo aumento da temperatura da água do mar chegou a até 90% da produção, um índice considerado sem precedentes pelo setor.

O professor explica que o aumento da temperatura da água provoca estresse fisiológico nos animais e pode deixá-los mais suscetíveis à ação de vírus, bactérias e outros microrganismos.

Por conta disso, pesquisadores da UFSC, em parceria com instituições do Brasil, França e Chile, criaram uma rede internacional de pesquisa para investigar os fenômenos de mortalidade das ostras e a relação deles com as mudanças climáticas.

 

— Queremos entender se o que está matando as ostras é um fator ambiental, infeccioso ou uma combinação dos dois — diz Rafael.

“Ostras verdes” e novas florações

Outro fenômeno recente chamou atenção de pesquisadores e produtores: o

aparecimento

das chamadas “ostras verdes” em cultivos do Sul da Ilha.

O fenômeno ocorre quando uma microalga azul-esverdeada é filtrada pelos moluscos e pigmenta as brânquias dos animais. A mesma ocorrência já é conhecida na França, onde as ostras verdes são consideradas uma iguaria gastronômica.

Ostras esverdeadas despertaram curiosidade de produtores no Sul da Ilha (Foto: LaBIOMARIS, Divulgação)

Segundo Rafael, o evento já havia sido registrado em Santa Catarina há mais de 10 anos, mas voltou a aparecer recentemente. Pesquisadores agora tentam identificar se a microalga encontrada em Florianópolis é a mesma presente na Europa e quais fatores ambientais favoreceram a floração.

Embora essa microalga específica não apresente riscos à saúde humana, o pesquisador alerta que mudanças climáticas podem aumentar a frequência de florações de outras espécies tóxicas.

— Algumas microalgas produzem toxinas que podem inviabilizar cultivos e representar riscos para o consumo humano — explica.

Tropicalização da costa e impactos na pesca

O aquecimento do oceano também altera o comportamento de diversas espécies marinhas. Segundo Regina Rodrigues, da UFSC, pesquisadores já observam um

processo

chamado de “tropicalização” da costa catarinense: espécies típicas de águas mais quentes começam a migrar para o Sul, enquanto espécies tradicionais da pesca local podem se deslocar para águas mais frias, próximas ao Rio Grande do Sul, Uruguai e Argentina.

A mudança ameaça diretamente atividades econômicas ligadas à pesca artesanal.

— Já houve anos em que a tainha praticamente não apareceu em Santa Catarina, mas os pescadores relataram grandes cardumes mais ao sul — afirma Regina.

O NSC Total ouviu pescadores que relataram à reportagem que não sentiram diferença nos cardumes. Pelo contrário, a safra da tainha de 2026 já entrou para a história na Praia de Cima, na Pinheira, em Palhoça, por exemplo.

Em apenas um mês, o número de peixes capturados praticamente igualou todo o volume registrado ao longo da temporada de 2025. Somente em maio, foram pescadas cerca de 92.986 tainhas, segundo levantamento do grupo Informações da Pesca (IDP), de Florianópolis.

O resultado surpreendeu até os pescadores mais experientes do litoral catarinense. A expectativa inicial era de uma boa safra, mas a quantidade de cardumes que chegou às praias ficou muito acima do esperado.

 

— A Praia de Cima surpreendeu esse ano e ainda tem muita tainha chegando. Pelas informações das

embarcações

que trabalham no alto-mar, ainda existem muitos cardumes no litoral do Rio Grande do Sul subindo para Santa Catarina — afirma Marcelo Alcioni, do IDP.

Segundo Marcelo, as condições climáticas têm sido determinantes para o fenômeno. Isso porque o vento sul mais fraco estaria favorecendo a permanência dos peixes na costa catarinense por mais tempo.

— O vento sul não está sendo muito forte, então a tainha vai viajando devagarzinho e entrando nas praias. Se tivesse vento sul forte, como elas chegaram cedo, provavelmente já teriam passado por Santa Catarina rumo ao Paraná e São Paulo — explica ele.

A expectativa dos pescadores é de que os próximos dias possam registrar novos grandes lanços nas praias da região. Para Marcelo, o auge da safra ainda pode estar por vir.

 

Mais ressacas e erosão costeira

Por outro lado, os efeitos das mudanças climáticas também avançam sobre as cidades costeiras. Com temperaturas mais elevadas, aumenta a energia das tempestades, dos ventos e das ressacas, intensificando processos de erosão em praias catarinenses. Regiões como Armação, Campeche e Morro das Pedras, em Florianópolis, já convivem com episódios frequentes de avanço do mar.

Regina Rodrigues também faz um alerta sobre a ocupação urbana desordenada no litoral catarinense.

— Dunas, vegetação costeira e manguezais funcionam como proteção natural contra ressacas e erosão. Quando destruímos essas áreas, aumentamos nossa vulnerabilidade climática — afirma.

Hottest May day for nearly 80 years as parts of UK hit heatwave threshold. Highest temperatures of 2026 in England, Wales and Northern Ireland as Kew Gardens in London reaches 32.3C

 

The sun rising over London, seen from Richmond Park, on Sunday. Photograph: Brook Mitchell/AFP/Getty

 by Hayden Vernon and Nadeem Badshah

England, Wales and Northern Ireland recorded their highest temperatures of 2026 on Sunday, which was also the UK’s hottest May day for at least 79 years.

Kew Gardens in west London recorded 32.3C (90.1F), Cardiff 27.4C and Armagh 23.4C.

Scotland reached 23.5C in Edinburgh, just 0.1C below the record of 23.6C set in Aboyne on 1 May.

The first area of the UK to hit the heatwave threshold was Santon Downham in Suffolk, which reached the criteria of recording temperatures of more than 27C for three consecutive days at 11.30am on Sunday.

The other areas officially in heatwave conditions are Heathrow, Kew Gardens and Northolt in London, Benson in Oxfordshire, Brooms Barn in Suffolk, and High Beach and Writtle in Essex.

Temperatures could rise again on Monday, with possible highs of between 33C and 34C.

The climate crisis is increasing the likelihood of extreme heat. Large parts of western Europe are experiencing similar peaks, and the French national weather agency, Météo-France, said periods of exceptional heat are to be expected “more and more often and more and more prematurely, and to be more and more intense”.

Margate beach was packed with sunbathers as temperatures climbed over the bank holiday weekend. Photograph: Chris J Ratcliffe/Reuters

A Met Office spokesperson said: “Breaking the 32.8C May record is around three times more likely now in our current climate than it would have been in natural climate conditions before the Industrial Revolution.

 

“What was around a one-in-100-year event is now around a one-in-33-year event.”

The Met Office sets the criteria for a heatwave, which vary by region. In London and its surrounding counties, a heatwave is defined by temperatures reaching or exceeding 28C on three consecutive days.

For many other areas of England and south-east Wales, the threshold is 26C or 27C. For the rest of Wales, Scotland, Northern Ireland and northern England it is 25C.

 

UK heatwave thresholds

Heatwave conditions are met when daily maximum temperatures meet or exceed the local heatwave temperature threshold for at least three consecutive days

 

Saturday was the UK’s first 30C day of the year, the earliest date that temperature has been reached since 1952.

Sunbathers flocked to beaches across the UK, and Lord’s cricket ground relaxed its strict dress code for its members’ pavilion. The Marylebone Cricket Club usually requires spectators there to wear lounge suits or tailored jackets and ties.

 There were also drinks breaks at the League One playoff final between Bolton Wanderers and Stockport County at Wembley and during the Premier League games as the top-flight football season concluded.

A dog cools off at water fountains in Battersea Park, south-west London. Photograph: James Manning/PA

People living in three villages in Kent experienced no water or low pressure for a second day. The affected areas were Charing, Challock and Molash near Ashford, where people first reported supply problems on Saturday evening.

South East Water apologised and said the issue had been resolved overnight, but that supply problems had resumed on Sunday as a result of pumping station issues.

The UK Health Security Agency (UKHSA) issued amber heat alerts on Friday morning for the East Midlands, the West Midlands, the east of England, London and the south-east.

Swimmers at Charlton Lido in south-east London. Photograph: Yann Tessier/Reuters

The alerts will remain in place until 5pm on Wednesday, meaning “an increase in risk to health for individuals aged over 65 years or those with pre-existing health conditions, including respiratory and cardiovascular diseases”, according to the UKHSA website.

There were also pleas for caution around open bodies of water such as lakes and quarries to reduce the risk of drowning.

According to 2024 data from the National Water Safety Forum, 61% of accidental water-related fatalities occurred in inland waterways, including rivers, canals, lakes, reservoirs and quarries. May that year had the largest number of deaths at 28.

The data also suggests many such deaths occur among people who are not intending to enter the water.

Prof Mike Tipton, the chair of the forum and an expert in water safety and cold water shock, said: “We encourage people to think before entering the water, and if they decide to go in, go to a supervised location, enter the water slowly to reduce the cold shock response and keep breathing under control.

“If people get into trouble, they should ‘float to live’ – roll on to back, tilt head back to keep airways out of the water, do as little sculling arm and leg exercise as necessary to stay afloat until breathing is back under control.”

Tipton also advised against entering the water to rescue someone struggling because doing so often leads to two people in trouble. People should call the emergency services, tell the person in the water to float and throw them a flotation aid if possible, he said.

Last night police were searching for a boy, 15, who had not been seen since going into a lake in Lincoln. Emergency services were called to Swanholme Lakes in the afternoon after reports the boy had got into difficulty in the water.

Israeli tech company aiming to cool the Earth with masses of tiny particles

 

A sun halo appears in the sky over northern Israel, May 2, 2026. (Ayal Margolin/Flash90)

by  By ToI Staff

 

Stardust Solutions wants to combat global warming by releasing millions of tons of particles to reflect small amounts of sunlight, NYT reports, but critics warn of dangers in playing with weather

 

An Israeli tech company has revealed the content of tiny particles it hopes will one day be used to combat global warming by scattering millions of tons of them into the atmosphere to reflect away sunlight, the New York Times reported Thursday.

Stardust Solutions had previously kept the makeup of its geoengineering particles a closely-guarded secret, protected with nondisclosure agreements.

As it turns out, they are made from amorphous silica, which is a food additive, and calcium carbonate, which is in eggshells and limestone.

 

The company, which is led by former figures from Israel’s nuclear program, on Thursday began publishing research papers on its product.

The idea is to disperse the particles at high altitude where they would reflect sunlight, cooling down the Earth.

“This is a very powerful tool that will be ready for testing very soon, and we want policymakers to start thinking seriously, ‘What will it take in practice?’” chief executive, Yanai Yedvab, told the Times.

So far, the company has only tested the particles in the laboratory and says it would not test them outdoors unless it were in partnership with a government to lay down the rules and limits of the test, according to the report.

Screen capture from video of Yanai Yedvab, chief executive of Stardust Solutions, April 2026. (YouTube)

Founded in 2023, Stardust Solutions has pulled in $75 million in funding from investors and has applied for a patent. Registered as a US company with an Israeli subsidiary, it has a lab in Ness Ziona, south of Tel Aviv.

The company has two types of particles it is working on. The first could reflect up to one percent of the sunlight, while the second, still in the testing phase, could reflect more than that.

Stardust executives estimate that a starting project to begin cooling the atmosphere could cost around $10 billion. It would require some 10 million tons of particles dispersed over several years, aiming to cool the atmosphere by 1.5 degrees Celsius.

It says the particles are biodegradable, not harmful to people or animals, and would not build up in the soil or oceans.

However, the idea of meddling with the world’s weather faces pushback.

More than 600 scientists and academics have called for an international ban on such projects, while Tennessee and Florida have already banned geoengineering.

Critics cite concerns of unintended consequences and that artificially cooling the planet might lessen calls for countries and industries to cut back emissions that are causing climate change. However, in recent years, as global temperatures have gone up, many researchers and some environmentalists have been more open to studying solar geoengineering methods, the report said.

 

Prakash Kashwan, a professor of environmental studies at Brandeis University, has warned that solar geoengineering could alter weather patterns, impacting food production and economies.

He highlighted those who live in South Asia, East Africa, and Latin America, where annual monsoons are vital for crops.

“There’s this social risk for at least two billion people that is directly connected to the lack of scientific understanding about how interfering with the global temperature thermostat is going to interfere with the monsoon formation,” he told the Times. “We don’t have a solution for those kinds of risks.”

Lasers in the sky: hi-tech missions track record snowpack loss in US west. Data from missions showing critically low snowpack on mountains across the west raises alarm among experts

A Lidar scan of snow on a mountain. Photograph: Airborne Snow Observatories

by  Ben Tracy of Climate Central

  

High above the jagged peaks of California’s Sierra Nevada, the view from the cockpit is breathtaking. At first glance, the mountains appear draped in a pristine white blanket. But as the flight crew gears up for a high-stakes mission, the sensors onboard this specialized aircraft prove that looks can be deceiving.

“This is a distinct dry year,” says Tom Painter, CEO of Airborne Snow Observatories.

Painter, who developed this technology at Nasa, isn’t relying on a visual inspection. His plane uses Lidar, or rapid pulses of laser light, to calculate snow depth with surgical precision. “The Lidar sprays out about 800,000 pulses per second,” he explains. The result is a 3D map of snow depth accurate to within 3cm. The technology also helps determine how much water is stored in the snowpack.

In the US west, where mountain ranges act as “frozen reservoirs”, state water managers rely on this data as a survival guide. It helps them plan for exactly how much water will eventually reach the faucets of millions of people and the critical farm fields that feed the nation.

 This year, the data is sounding an alarm.

 

 The national drought picture is increasingly grim. According to the latest US Drought Monitor, more than 60% of the lower 48 states are now gripped by drought. It’s the most widespread spring dry spell since the monitor began in 2000. While the south-east is now battling “summer-sized” wildfires in Georgia and Florida, the west is facing a different kind of crisis: a snow drought-fueled water shortage.

 

A record-warm winter followed by a blistering March heatwave, both fuelled by heat-trapping pollution, has decimated the western snowpack. According to Climate Central, the total water stored in the western snowpack this winter hit its lowest level on record right when it should have been hitting its annual peak.

“In March the spigot shut off and it shut off across the entire western US,” Painter says. “Loss of snowpack like we’ve never seen. It’s not in the record at all. So this is unprecedented.”

The numbers back him up: the statewide snowpack in California stood at a mere 18% of average on 1 April and has declined ever since.

Standing by a rushing stream outside Reno, Nevada, Tom Albright, the state’s deputy state climatologist, says spring runoff from snowmelt in the mountains is two months ahead of schedule. “We wish we could tell it to stay put a little longer,” Albright says.

The danger of an early melt is twofold. First, once that snow is gone, the landscape begins to dry out months ahead of schedule which can fuel wildfires. Second, major reservoirs on the Colorado River that are already critically low, will not be replenished due to the lack of snowpack. “What happens when we don’t have the snowpack is we lose what water there was early and then we’re left with this really long dry season,” Albright says. When asked what concerns him most about the coming months, his answer is immediate: “Fire. Particularly because we have such a broad area that’s affected.”

For decades, the water systems of the west were built on the assumption that the snow would stay in the mountains until the heat of mid-summer. The climate crisis is rewriting that playbook.

While this year’s drought is anomalous when looking at the historical record, experts warn it is a preview of the coming decades.

“As we look forward this year will become less and less unusual and may become not unusual at all at some point in the future,” Albright warns.

Airline emissions in Europe top pre-Covid levels despite pledge to decarbonise. Promises to cut emissions and use more fuel-efficient planes fail to stop rise, with Ryanair’s carbon footprint 50% up on 2019

 

The T&E thinktank says that although the EU and the UK have tried to manage environmental costs via the emissions trading system, the scheme does not price in most of the sector’s pollution, as it only includes flights entirely within Europe. Photograph: Lewis Whyld/PA

 by Gwyn Topham Transport correspondent

 

Emissions from flying in Europe have now passed pre-pandemic levels, with Ryanair’s carbon footprint 50% higher than in 2019, research has shown.

Total aviation emissions continue to increase despite industry pledges to decarbonise and the introduction of more fuel-efficient planes, driven by the massive expansion of low-cost carriers.

According to analysis by thinktank Transport & Environment (T&E), Ryanair’s CO₂ emissions alone in 2025 reached 16.6 megatonnes (Mt) of CO₂ – around the same amount as the total annual emissions of a small European country such as Croatia. The airline carried just over 200 million passengers in 2025, compared with 140 million in 2019.

The entire European aviation sector emitted 195Mt of CO₂ in departing flights last year, a 2% increase on levels before Covid paused international travel.

 

Although the EU and the UK have tried to manage some of the environmental costs through the emissions trading system (ETS), T&E said the system does not price in most of the sector’s pollution, as it only includes flights entirely within Europe.

That means long-haul flights on legacy carriers’ aircraft, which burn more fuel, are outside its scope. Airlines operating predominantly within Europe pay more under the system – Ryanair pays an average of €50 (£36) a tonne of carbon, while Lufthansa pays about €20. London-New York traffic alone generated nearly 1.4Mt of CO₂ in 2025, but is not drawn into the ETS.

T&E wants the carbon market extended to all departing flights to raise more public revenue and accelerate aviation’s slow decarbonisation. Such a move, it said, could quadruple the €4.1bn raised for EU states by 2030, and fund production of sustainable aviation fuel and measures to avoid contrails, the plumes of cloud formed by planes in certain conditions that could exacerbate global heating.

While the aviation industry has been lobbying to suspend or weaken ETS and other taxes and regulatory requirements on flying during the Middle East crisis, the report found that the carbon market costs were negligible compared with fuel volatility. Jet fuel prices that have roughly doubled from pre-Iran war levels add €90 a passenger on long-haul flights, compared with just €3 from following the sustainable aviation fuels mandate.

“Ticket prices are rising because of Europe’s reliance on fossil fuels, not because of the climate measures intended to steer the sector away from them,” Giacomo Miele, author of the T&E analysis, said.

“Aviation emissions hitting a new high is a clear signal that the industry has no intention of cleaning up its act. It is time to stop subsidising fossil fuel dependency and start investing in the future of a sustainable aviation sector.”

 

A spokesperson for Ryanair said its greenhouse gas emissions (GHG) were rising as it was Europe’s fastest-growing airline, adding: “All of this growth takes place at lower fares but on new fuel-efficient aircraft, so our GHG per passenger are falling. Ryanair’s growth is also displacing air travel on less-efficient legacy airlines whose GHG per passenger is much higher than Ryanair’s.”

Ryanair said the ETS emissions figures were “completely discredited” since they excluded flights operated by airlines who were “indefensibly exempted from their fair share of enviro taxes by Europe’s discriminatory ETS system, which taxes only intra-EU flights while it exempts all flights including the most polluting long-haul flights”.

Ryanair says that when all flights are included it ranks behind Lufthansa, Air France/KLM and British Airways owner IAG for total emissions, while having the lowest CO₂ emissions a head of the big European airlines, of about 64g a passenger kilometre.

Alaska’s 2025 mega tsunami highlights risk to cruise lines as glaciers retreat. Researchers say 481-metre wave in fjord was triggered by rockslide linked to climate crisis

 

Glaciers in Alaska's Denali national park have been found to be melting faster than at any time in the past four centuries due to rising summer temperatures. Photograph: VW Pics/Universal Images Group/Getty Images

by Maya Yang

A mega tsunami in Alaska last year in a fjord visited by cruise ships is a stark warning of the risks of coastal rockslides and glacier retreat fueled by the climate crisis, a new study warns.

Scientists recorded the world’s second-tallest tsunami after it struck the Tracy Arm fjord in south-east Alaska last August after a massive rockslide around the toe of a glacier. The tsunami reached 481 metres (1,578ft) in height; by comparison the Eiffel Tower is 330 metres (1082ft).

According to the new research published in Science on Wednesday and led by Dan Shugar, a geomorphologist of the University of Calgary, the sequence began at 5.26am local time on 10 August 2025. A large landslide collapsed 1km vertically onto the South Sawyer glacier and into the narrow, 48km fjord, producing the huge tsunami.

An oblique aerial photograph of Sawyer Island, largely stripped of trees, taken during a US Geological Survey reconnaissance flight on 13 August 2025. Photograph: John Lyons/U.S. Geological Survey.

There were no fatalities at the early hour but the area is visited by approximately three cruise ships passing through daily, along with other vessels traveling within a few kilometers of the landslide site.

 

Just hours after the landslide, a sightseeing vessel from Juneau and a National Geographic tour boat – each capable of carrying more than 100 passengers, were due to enter the fjord. The day before, two cruise ships carrying thousands of passengers had already visited the area, with another scheduled to arrive the following day.

At the time of the event, Dennis Staley from the US Geological Survey called the tsunami “a historic event”, adding to the Guardian: “I feel like we dodged a bullet.”

“With fjord regions increasingly visited by cruise ships, and climate change making similar events more likely, this unanticipated, near-miss event highlights the growing risk from landslides and tsunamis in coastal environments,” researchers said in their report.

A near-source animation of the tsunami generated by the August 10, 2025 Tracy Arm landslide.

 

They also noted that the tsunami was only slightly smaller than the world’s tallest, recorded in Lituya Bay, Alaska, in 1958 at 530 metres (1,728ft). The Tracy Arm event also triggered a 36-hour seiche – a standing wave that oscillates within a closed body of water.

The study further found that the landslide generated long-period seismic waves equivalent to those of a 5.4 magnitude earthquake.

Eyewitness accounts in the report highlighted the tsunami’s far-reaching effects. A group of kayakers camping on Harbor Island, about 55km away, reported water surging past their tent, sweeping away one of their kayaks along with other gear.

Another observer aboard a motor vessel in No Name Bay, roughly 50km from the landslide, described seeing a 2 to 2.5 metre wave cresting along the shoreline from the direction of Tracy Arm, followed by a second wave of about 1 metre, the researchers said.

In the study, researchers found that landslide-generated tsunamis can “have substantially higher runups (the maximum height water reaches on a slope) than earthquake tsunamis, owing to larger, localized variations in water depth and direct water-column displacement by slope failure – most pronounced in confined water bodies like fjords”.

Pointing to climate crisis-driven glacier retreat, researchers noted that “without the rapid glacier retreat, the landslide would likely not have resulted in such a wave because it would have collapsed entirely onto glacier ice or might not even have occurred at all”.

In recent years, fjords with retreating tidewater glaciers have become increasingly popular destinations for cruise ships. According to the study, annual cruise passenger numbers in Alaska have risen from about 1 million in 2016 to 1.6 million in 2025.

Aerial photographs show a clear trimline along the far side of the fjord where a tsunami stripped vegetation from the slopes. Photograph: John Lyons/U.S. Geological Survey

Combined with accelerating glacier retreat and permafrost degradation driven by the climate crisis, the risk of large-scale landslide-generated tsunamis is also increasing across the Arctic.

As a result, researchers emphasized both the scale and potential reach of such events. They called for stronger risk mitigation measures, including systematic monitoring of unstable slopes, more realistic tsunami-modeling scenarios and enhanced protection for local communities, tourists and critical infrastructure.

Several tsunamis have occurred in Alaska over the last decade, with a large landslide generating a 18 to 55 metre wave in Kenai fjords national park in 2024, as well as another landslide near a receding glacier in Taan fjord in south-east Alaska that caused a 193 metre tsunami in 2015.

‘Point of no return’: New Orleans relocation must start now due to sea level, study finds. Louisiana’s cultural hotspot could be surrounded by Gulf of Mexico before end of this century, authors say

 

By Oliver Milman

 

The process of relocating people from New Orleans should start immediately, as the city has reached a “point of no return” that will see it surrounded by the ocean within decades due to the climate crisis, a stark new study has concluded.

Ongoing sea-level rise and the rampant erosion of wetlands in southern Louisiana will swallow up the New Orleans area within a few generations, with the new paper estimating the city “may well be surrounded by the Gulf of Mexico before the end of this century”.

Low-lying southern Louisiana faces multiple threats, with rising sea levels driven by global heating, compounded by strengthening hurricanes, also a feature of the climate crisis, and the gradual subsidence of a coastline that has been carved apart by the oil and gas industry.

 

Southern Louisiana is facing 3-7 metres of sea-level rise and the loss of three-quarters of its remaining coastal wetlands, which will cause the shoreline “to migrate as much as 100km (62 miles) inland”, thereby stranding New Orleans and Baton Rouge, according to the study, which compared today’s rising global temperatures with a period of similar heat 125,000 years ago that caused a rise in sea level.

This scenario makes the region the “most physically vulnerable coastal zone in the world”, the researchers state, and requires immediate action to prepare a smooth transition for people away from New Orleans, which has a population of about 360,000 people, to safer ground.

Louisiana has already experienced population loss in recent years, and this trend will accelerate in a disordered way, the paper warns, should no action be taken to confront the perils faced by its largest city and surrounding communities.

“While climate mitigation should remain the first step to prevent the worst outcomes, coastal Louisiana has evidently already crossed the point of no return,” added the perspectives paper, published in the Nature Sustainability journal. A perspectives paper is a scholarly article that provides an assessment, rather than new data.

Billions of dollars have been spent to fortify New Orleans with a vast network of levees, floodgates and pumps erected after 2005’s catastrophic Hurricane Katrina. But the growing threats to the city mean the levees, which already require hefty upgrades to remain sufficient, will not be able to save the city in the long run, the new paper warns.

 

“In paleo-climate terms, New Orleans is gone; the question is how long it has,” said Jesse Keenan, an expert in climate adaptation at Tulane University and one of the paper’s five co-authors.

 

Keenan said the timeframe available to plan a retreat isn’t certain but “it’s most likely decades rather than centuries”.

“Even if you stopped climate change today, New Orleans’s days are still numbered,” he added. “It will be surrounded by open water, and you can’t keep an island situated below sea level afloat. There’s no amount of money that can do that.”

City, state and federal leaders should begin work to help support people moving away from the New Orleans region in a coordinated way, starting with the most vulnerable communities, such as those in Plaquemines parish who live outside the levee system, Keenan said.

“New Orleans is in a terminal condition, and we need to be clear with the patient that it is terminal,” he said. “There is an opportunity for palliative care, we can transition people and the economy. We can get ahead of this.”

But, he added, “no politician wants to first give this terminal diagnosis. They will speak about it behind closed doors, but never in public.”

New Orleans faces obvious challenges – situated in a bowl-shaped basin below sea level, the city already has 99% of its population at major risk of severe flooding, the worst exposure of any US city according to a separate study released last week.

“Even compared to all other US cities, New Orleans really stands out, which is alarming,” said Wanyun Shao, a co-author of this study and a geographer at the University of Alabama.

“There is no specific timeline to how long New Orleans has left but we know it’s in big trouble. They are facing one of the highest sea level rises in the world and I don’t know how long human effort can fight against that tide. It’s like a timebomb.”

Shao said she concurred that relocation of people would have to take place. “I know it’s a politically and emotionally charged issue, there are people with a deep attachment to New Orleans,” she said. “But managed retreat, no matter how unappealing it may be, is the ultimate solution at some point.”

A major pressure upon this southern cultural hotspot is that its surrounding land is briskly receding. Since the 1930s, Louisiana has lost 2,000 sq miles of land to coastal erosion, equivalent to the size of Delaware, with a further 3,000 sq miles set to vanish over the next 50 years. The rate of land loss is so rapid that a football pitch-sized area is wiped out every 100 minutes.

To help counter this, Louisiana last decade settled upon a new sort of plan that eschewed building yet more flood defenses and instead sought to harness the Mississippi River’s natural ability to rebuild land. Levees and other infrastructure have, until now, straitjacketed the naturally meandering Mississippi and pushed the sediment it carries straight into the Gulf of Mexico, rather than replenish the coastal wetlands.

The so-called Mid-Barataria Sediment Diversion project, which broke ground in 2023, would help restore a more natural flow in the Mississippi Delta and allow sediment to build up in coastal areas where it has been lost. More than 20 sq miles of new land would be created over the next 50 years under the plan, the project estimated.

However, Jeff Landry, Louisiana’s Republican governor, scrapped the project last year, arguing its $3bn cost was too high and that it threatened the state’s fishing industry. “This level of spending is unsustainable,” Landry said at the time, adding that the project imperiled the livelihoods of “people who have sustained our state for generations”.

Proponents of the project, which was funded via a settlement from BP over the Deepwater Horizon disaster in 2010, decried the decision as disastrous for the state, pointing out fishing communities will need to move anyway because of worsening erosion.

Garret Graves, a Republican former congressman who once led the state’s coastal restoration agency, said Landry was guilty of a “boneheaded decision” that would “result in one of the largest setbacks for our coast and the protection of our communities in decades”.

According to the new research paper, the loss of the sediment diversion plan “effectively means giving up on extensive portions of coastal Louisiana, including the New Orleans area”.

A legal effort to force oil and gas companies to pay for damage to Louisiana’s coastline, meanwhile, is also in doubt. This month, the US supreme court allowed the fossil fuel industry to federally contest a state jury decision that Chevron pay $740m to remedy harm caused to wetlands by dredging canals, drilling wells and dumping wastewater.

“The combination of these decisions is driving a scenario where the state has stopped trying to build land,” Keenan said. “That just accelerates the timeline. They could be buying time, but that option is foreclosed now, meaning it’s a certainty the New Orleans levees will fail again multiple times. The flood water will have nowhere else to go.”

While the US has never wholesale moved a major city before, numerous communities have relocated for economic reasons in the past, with some now being shifted due to the climate crisis, too. In Louisiana, the government could start planning and building appropriate infrastructure in safer areas on the other side of Lake Pontchartrain, the large estuary that sits to the north of New Orleans, Keenan said.

“This could be an opportunity for New Orleans to help migrate people further north, invest in long-term infrastructure and make that sustainable,” Keenan said.

“That exodus has already begun, so if nothing is done, people will just trickle out over time and it will be an uncoordinated mess. The market will speak as people won’t be able to get insurance. Louisiana has to stop the bleeding and acknowledge this is happening. But at the moment there is no plan.”

Timothy Dixon, an expert in coastal environments at the University of South Florida who was not involved in the new paper, said the study “does a nice job” of highlighting the challenge Louisiana faces with subsiding land combined with rising sea levels.

“New Orleans is not going to disappear in 10 years or anything like that, but policymakers really should’ve thought about a relocation plan a century ago,” said Dixon, whose own research has recommended a measured retreat from coastal Louisiana.

“Governments may not have the ability to just command people to leave, but people will volunteer to move and we are seeing that already. I’m not optimistic our political system is capable of dealing with this stuff, it will take leadership and unpopular decisions. Also, many people don’t want to move. They love where they are born.”

Landry’s office was contacted for comment but did not respond.