August was the joint hottest month ever observed, tying with July 2023, as the most severe super El Ni帽o on record amplified temperatures already heightened by global warming.

The monthly mean temperature was 1.65掳C above pre-industrial levels, according to the European Union鈥檚 Copernicus Climate Change Service. Humans have not experienced temperatures warmer than this summer in the past 100,000 years, according to at Copernicus.

August was also a record-warm month for the extra-polar ocean 鈥� the regions lying just outside the Arctic and Antarctic circles 鈥� peaking at 21.1掳C, the hottest temperature ever observed in the sea surface. That included unprecedented temperatures in the tropical Pacific, where winds have slackened and warm waters have been sloshing back towards the eastern Pacific, creating the strong El Ni帽o.

鈥淎ugust 2026 is remarkable not simply because it鈥檚 yet another temperature record that鈥檚 been broken but because multiple parts of the climate system have reached unprecedented levels at the same time,鈥� she says.

The records will keep being broken as the El Ni帽o intensifies through December, she predicts, with some months likely to be as much as 2掳C above average.

The record August temperature caps off western Europe鈥檚 hottest summer on record. That warmth drives extreme weather and climate catastrophes. It makes heatwaves more likely and allows the atmosphere to hold more moisture, worsening storms.

Four major heatwaves in Europe, as well as severe drought, fuelled massive wildfires near cities like Bordeaux in France and Madrid in Spain and lowered water levels in major rivers to reveal everything from long-lost woolly mammoth bones to Nazi boats.

Free newsletter

Sign up to The Earth Edition

Sign up to newsletter

At least in Europe during the heatwaves than would be statistically expected, and including wheat are expected to be lower than usual.

The heat in August was also linked to a glacier collapse that destroyed several towns in Nepal and Tibet, with at least 1300 people dead and more than 5500 still missing.

鈥淔or every degree of warming, the extreme events鈥� intensify, so in summer we get more frequent, more intense, more longer-lasting heatwaves,鈥� Burgess says. 鈥淭his obviously has a direct impact on our food security.鈥�

In light of the temperature record, the Energy and Climate Intelligence Unit (ECIU) 鈥� a UK-based think tank 鈥� called on leaders meeting in November for the COP31 climate summit to both reverse the rise in greenhouse gas emissions and also invest more in adapting to the current impacts.

Why the extremes of climate breakdown will continue to take us by surprise

The relentless heatwaves that have hit the northern hemisphere this summer have made the climate threat real for many 鈥� but preparation and adaptation will take us only so far

鈥淭he task now is to match the scale of the science with the scale of action鈥� accelerating the transition away from coal, oil and gas to bring our climate back into balance,鈥� , international lead at the ECIU, said in a statement.

The United Nations Environment Programme said this month that the world will 鈥渙vershoot鈥� the Paris Agreement goal of preventing warming of more than 1.5掳C and should now focus on reversing this warming at a later date, including with approaches like carbon dioxide removal. 听

鈥淭he sooner we can bring temperatures back down, the less time we overshoot, the better it will be for our climate system,鈥� says Burgess.

鈥淚 often get asked whether this is the 鈥榥ew normal鈥�. The simple answer is no,鈥� at Imperial College London said in a statement. 鈥淯ntil we stop burning fossil fuels, these records will continue to tumble, and the extremes will worsen faster than we are able to adapt.鈥�

Growing seaweed has long been as a way to slow climate change. But this approach is mistaken, a new study argues, as the loss of seaweed emits far more carbon than what is being absorbed by attempts to grow it.

Seaweeds absorb an estimated 3.7 billion tonnes of carbon dioxide through photosynthesis every year, drawing it from seawater, which then draws more CO2 from the air above. They mostly grow near the coast, where they are eventually digested or decomposed, emitting carbon. But fragments of fronds, as well as from the seaweeds that dissolve in seawater, can sink into the deep sea, sequestering a of the CO2 as 鈥溾�� for thousands of years.

女生小视频s and start-ups have suggested that seaweed growth, especially kelp, could be expanded to take up more CO2, something the UN has said we will need to do on a massive scale to eventually reverse dangerous levels of global warming.

But there are concerns that cultivating huge amounts of seaweed could backfire and diminish growth of phytoplankton, another important carbon sink. And even the kelp forests we currently have, which are estimated to cover around 640,000 square kilometres worldwide 鈥� an area slightly larger than France 鈥� are dying off as ocean temperatures reach record highs.

Now, at the University of Western Australia and her colleagues have concluded that, with some 60 per cent of kelp forests in decline, these ecosystems could eventually begin emitting more CO2 than they absorb. Researchers, as well as governments and companies trying to offset their emissions, need to focus on preserving rather than growing seaweed, they suggest.

鈥淚nstead of asking how much carbon we can remove with seaweeds, we should be asking how much carbon we can stop from being released as these ecosystems are damaged by climate change,鈥� says Filbee-Dexter.

Free newsletter

Sign up to The Earth Edition

Sign up to newsletter

Some studies have the possibility of removing a billion tonnes of carbon per year with seaweed, but there are already signs that this may not be feasible. For instance, the US carbon removal start-up Running Tide, which raised $70 million to cultivate kelp on wooden buoys that would gradually sink into the deep sea, in the open ocean and shut down last year.

Other projects have tried to bring back lost kelp forests. An experiment in northern Norway of kelp by poisoning seaweed-eating sea urchins, which can multiply when overfishing and hunting remove their predators.

While kelp restoration like this is a win for biodiversity, it only draws down about 50,000 tonnes of CO2 per year. Meanwhile, global kelp loss is emitting an estimated 14 million tonnes of CO2 per year.

The study by Filbee-Dexter and her colleagues also notes that preserving kelp ecosystems is at least eight times cheaper per hectare than restoring them, yet only 2 per cent of kelp forests lie in protected areas.

Firms are also cultivating seaweed to make nori for sushi, animal feed and thickeners for products like ice cream and toothpaste. Fragments of seaweed still drift away and sink into the deep sea, and aquaculture companies like Kelp Blue have to eventually sequester and offset hundreds of millions of tonnes of CO2.

Seaweed farming now takes up 4000 square kilometres of ocean. But that鈥檚 only about a third of the kelp forest cover lost each year. And after factoring in emissions associated with farming operations 鈥� like boat fuel and plastic lines 鈥� nine out of 11 seaweed farms were found to emit more CO2 than they sequestered in a .

Microplastics could be hampering the ocean鈥檚 ability to capture carbon

A global survey of microplastics in oceans reveals that tiny particles of plastic are prevalent throughout the water column, which could harm marine ecosystems and affect carbon storage in the deep sea

鈥淪eaweed restoration and farming is unlikely to be a major climate change solution,鈥� Filbee-Dexter says. 鈥淏ut that doesn鈥檛 mean it isn鈥檛 worthwhile.鈥�

Restoration can improve biodiversity, and farming can make low-carbon alternatives to fossil-fuel products like fertiliser, she notes.

at Queen鈥檚 University Belfast in the UK, however, says scientists don鈥檛 have a solid enough understanding of how much carbon seaweed sequesters to write it off yet. Macroalgae restoration, conservation and farming can all still be climate solutions, even if their impact has often been exaggerated in the past, she argues.

鈥淏lue carbon is part of the puzzle,鈥� she says. 鈥淚t can make a contribution. The question is how that is determined and validated.鈥�

Short-term geoengineering to brighten clouds over the eastern Pacific Ocean could limit the damage caused by El Ni帽o and save the global economy trillions of dollars, although there could be winners and losers from the disruption of natural cycles.

The El Ni帽o climate phase occurs when easterly winds weaken, allowing warm water built up in the western Pacific to slosh back across the central and eastern parts of the ocean. That heats the atmosphere and raises global temperatures, with losses to economic growth estimated in the trillions of dollars.

What could become a very strong or 鈥渟uper鈥� El Ni帽o is now developing in the eastern Pacific. But climate modelling has suggested that, in the future, a geoengineering method called marine cloud brightening might be able to cut this warming short.

The technique involves spraying tiny droplets of seawater into the air below low-lying stratocumulus clouds, where moisture condenses onto them. The clouds become whiter thanks to the increase in the number of droplets, reflecting more sunlight back to space.

Shading part of the eastern Pacific called the Ni帽o 3.4 region via cloud brightening could interrupt the feedback loops that cause an El Ni帽o to develop. Cooler sea surface temperatures would strengthen the trade winds to again blow warm water back into the western Pacific. More cool water would then well up from the depths of the eastern Pacific, further cooling surface temperatures, and so on.

鈥淵ou can basically stop the dominoes from falling early when you do marine cloud brightening,鈥� says at the University of California, San Diego, who worked on the study. 鈥淲e鈥檙e kicking the cycle in the other direction.鈥�

Free newsletter

Sign up to The Earth Edition

Sign up to newsletter

Wan and her colleagues got the idea from the 鈥渂lack summer鈥� of catastrophic bush fires in Australia in 2019-2020, which were followed by La Ni帽a, the opposite phase of El Ni帽o that lowers global temperatures. Research has that drifting smoke particles brightened clouds and cooled the eastern Pacific, intensifying and prolonging the 鈥渢riple dip鈥� La Ni帽a that began in 2020 and persisted through three winters, rather than just one or two.

The study modelled what cloud brightening could have done to the super El Ni帽o events of 1997-1998 and 2015-2016. It found that nine months of spraying seawater would have nearly halved warming of the Ni帽o 3.4 region, from 2掳C or more to a little over 1掳C. It would have ended the El Ni帽o by January, shaving several months off the events.

The hypothetical cloud-brightening mission would have been massive, involving an estimated 2400 ships and delivering an amount of seawater spray that isn鈥檛 possible with current nozzle technology. But it would have turned a super El Ni帽o into a moderate one.

Wan says she was surprised how well it seemed to work, given that it could only be started in June, once El Ni帽o had clearly begun developing.

at the University of Exeter, UK, warns that these results might not translate to the real world, where warming seas typically start dissipating low-level clouds, leading to further warming and dissipation through a feedback loop.

鈥淚n a model with a stronger cloud feedback, you would have to do more aerosol injection,鈥� he says. 鈥淭he experiments seem to be at the limit of what can be done.鈥�

Wan admits this approach could have unexpected consequences, since the model only projected the impact over two-year periods. In both simulations, La Ni帽a started earlier after El Ni帽o subsided, and in the 2015-2016 case, this subsequent cooler phase became stronger. That could be bad news for regions like the Horn of Africa, where strong La Ni帽as have, in the past, disrupted rainfall and .

But she says the idea is worth further research. Unlike geoengineering aimed at reducing global temperatures for the long term, short-term geoengineering like this could avoid the risk of 鈥�termination shock鈥�, where any disruption to the spraying of low-level seawater or stratospheric aerosols could allow years of pent-up warming to come roaring back.

鈥淭his study is opening up doors for a completely new target for geoengineering research, which is climate variability and things like El Ni帽o,鈥� says Wan. 鈥淚t鈥檚 potentially very powerful, because you鈥檙e not locked into these long-term risks.鈥�

Tens of millions of dollars have been invested in growing seaweed to absorb carbon dioxide and slow climate change. But due to unwanted side effects, this technique could fail to significantly decrease the CO2 in the atmosphere, and it might even increase it.

Carbon dioxide removal (CDR) will be needed to meet the Paris Agreement goal of limiting global warming to 2掳C, to the UN, and many have hoped seaweed could be a cheap way to do that. The US start-up Running Tide raised $70 million to grow seaweed on pucks of wood that would eventually become sodden and sink to the deep sea, sequestering the carbon, but it ran out of financing and last year.

Dutch company Kelp Blue has raised at least $2 million to expand the seaweed that it is currently growing to produce sustainable agricultural fertiliser in Namibia. Because small particles of this seaweed may break off and drift into the depths, it it could eventually 鈥渟equester and offset鈥� up to 500 million tonnes of CO2 per year.

But a global seaweed-cultivation programme could in many places rob nutrients from phytoplankton, which also sequester carbon when they die and sink to the depths, two studies have found.

鈥淚t could backfire locally,鈥� says at the University of Bern, Switzerland, who worked on one of the studies. 鈥淚n some places, you鈥檇 actually reduce how much carbon the ocean takes up. The potential is extremely limited, with large ecological consequences.鈥�

Except for sargassum, macroalgae species live near the coast, where nutrients are plentiful. During photosynthesis, they consume carbon dissolved in seawater, allowing the ocean to absorb more CO2 from the atmosphere.

Free newsletter

Sign up to The Earth Edition

Sign up to newsletter

Marine organisms and microbes eventually most of that seaweed, emitting an estimated nine-tenths of its carbon. To sequester more carbon, seaweed would have to be grown or transported further offshore, where it could be baled or otherwise sunk to the deep sea.

But nutrients are scarce in the open ocean, and most research before now hasn鈥檛 examined how the lack of iron could limit seaweed growth. Berger and her colleagues modelled the cultivation of 20 billion tonnes of seaweed per year across waters up to 200 nautical miles from coastlines.

They found the seaweed would quickly start depleting nitrogen, phosphorus and iron in the water, and after 25 years, its growth would have declined 95 per cent. Moreover, this would diminish global phytoplankton growth by as much as 8 per cent.

In some scenarios, seaweed cultivation could still remove billions of tonnes of CO2. But depending on what species of seaweed are grown and how much nutrients they consume, it could also increase the amount of carbon in the atmosphere by half a tonne for every tonne of seaweed carbon grown.

Patches off Senegal and southern Australia, about 0.05 per cent of the ocean, are the only places seaweed could flourish without significantly decreasing phytoplankton, the model suggests.

鈥淚f you have only a few very specific locations, you can鈥檛 grow enough seaweed to have a gigatonne of removal,鈥� says Berger.

In another study, at the UK National Oceanography Centre and his colleagues modelled what would happen if seaweed-cultivation areas were fertilised with iron, finding that up to 40 billion tonnes of CO2 could be removed each year. But that would also halve the plankton in the ocean, with dire consequences for the fish that eat them.

鈥淵ou鈥檙e robbing the surface ocean of nutrients鈥� and transferring those to depth,鈥� says Yool. 鈥淓ssentially, you鈥檙e curtailing or slowly strangling the natural ecosystem.鈥�

Furthermore, such seaweed cultivation and sinking would require setting up cages or other frameworks across 14 per cent of the ocean surface, largely in the nutrient-rich but stormy seas of the Southern Ocean and northern Pacific and Atlantic.

And if all this ocean wasn鈥檛 fertilised with iron, the seaweed carbon removal wouldn鈥檛 fully compensate for the plankton loss, increasing CO2 in the atmosphere by up to 700 million tonnes per year.

鈥淵ou can鈥檛 just grow macroalgae and assume that you鈥檙e going to be undertaking CDR if you鈥檙e not accounting for offsetting phytoplankton growth,鈥� says at the UK National Oceanography Centre, another member of the team.

El Ni帽o has officially begun, and it鈥檚 more likely than not that it will develop into a 鈥渟uper鈥� El Ni帽o. Either way, it will amplify temperatures and extreme weather around the world.

El Ni帽o is a natural climate phase that occurs when east-to-west winds weaken in the tropical Pacific, allowing water concentrated in the 鈥渨arm pool鈥� on the western side of the Pacific to wash back towards the eastern side. This broad smear of warm water heats the atmosphere, raising the global temperature.

The US National Oceanic and Atmospheric Administration (NOAA) has now declared the onset of El Ni帽o because sea surface temperatures in the central-eastern Pacific have been more than 0.5掳C above normal for the past month, and climate models project they will remain there for at least the next six months. The Japan Meteorological Agency has also declared that El Ni帽o has begun.

鈥淲e are seeing westerly wind anomalies from the dateline almost all the way to about 130掳 west, so basically the entire area south of Hawaii,鈥� says at NOAA鈥檚 National Weather Service. 鈥淲hat that means is significantly reduced trade winds there, so it鈥檚 allowing the atmosphere and the ocean to slosh to the east and bring that warm water with it.鈥�

NOAA also said there is a 63 per cent chance this El Ni帽o will become a very strong or 鈥渟uper鈥� El Ni帽o, when sea surface temperatures in the equatorial Pacific breach 2掳C above average. It could be the hottest El Ni帽o ever seen.

鈥淭his latest El Ni帽o is likely to be a significant event, perhaps one of the most intense on record,鈥� said at the Met Office, the UK鈥檚 weather service, in a statement.

Free newsletter

Sign up to The Daily

Sign up to newsletter

Out of 200 model simulations, none show sea surface temperatures in the central-eastern Pacific going back below 1掳C above normal this year once El Ni帽o gets going, according Rosencrans. Several models project sea surface temperatures could reach 2.6掳C higher than usual, and one Canadian model says they could even hit 3掳C, which would smash the 2.5掳C record set during the super El Ni帽o of 1982-83. During that event, flooding killed an 1300 to 2000 people in Peru.

Temperatures will likely peak by the end of the year and simmer well into 2027. This rush of heat comes on top of global warming of 1.36掳C, leading scientists to predict that next year will be the hottest ever observed. The boost in temperatures will worsen extreme weather, since a warmer atmosphere holds more energy and moisture. El Ni帽o also tends to bring abnormally wet or dry weather to different regions.

鈥淲hat it does is change the odds of those rainfalls听or heatwaves or cold snaps happening in certain places,鈥� says Rosencrans. 鈥淭he atmosphere [is] throwing loaded dice in a way, so you鈥檙e more likely to get rainfall in southern California, you鈥檙e more likely to get drying in the maritime continent, and potentially even into India [and] the northern parts of Australia.鈥�

The southern US is more likely to see reduced rainfall this summer, followed by cool, wet, stormy weather this winter, with cold snaps possible as far south as Mexico. South-East Asia and south-east Africa could face heat and drought this summer and winter, raising the risk of wildfires.

El Ni帽o can tend to bring colder winters to the UK, but it can also bring warmer, wetter conditions, said independent climate scientist at a briefing. Many other climate factors affect Europe, meaning El Ni帽o impacts are less certain. 鈥淚t tends to change the storm tracks, and you often get these warmer, wetter conditions,鈥� says Gilbert. 鈥淚n the past, for the UK, you鈥檝e seen more storm incidents than otherwise鈥� but the direct connection in the UK is less obvious than in the US or Australia.鈥�

How climate change has pushed our oceans to the brink of catastrophe

For decades, the oceans have absorbed much of the excess heat caused by greenhouse gases. The latest observations suggest they are reaching their limits, so how worried should we be?

Heat or drought could impact commodities like rice, coffee and chocolate, and disrupt food supplies around the world. If rice yields decline, India 鈥� a major producer 鈥� could limit exports and cause rice to become scarcer and more expensive in other countries, says at the University of Maryland.

鈥淭he impacts鈥� ripple through the food system,鈥� he says. 鈥淲e think about a commodity like rice, which is important for food security for many people, and we do have concerns about potential monsoon deficits leading to lower rice production.鈥�

El Ni帽o may be getting more frequent, and global warming will regardless exacerbate its consequences, which could compound issues like migration, says at the University of Oxford. 鈥淲e need long-term preparedness and planning as we continue with climate change and we also continue with El Ni帽o amplifying that.鈥�