Anchovy disappearance signals potentially record-breaking El Nino intensified by climate change

Anchovies are an unlikely bellwether for a building climatic event, but their disappearance from the coast of South America is heralding one of the biggest El Ninos in living memory.

These small fish usually live in colossal shoals along the Pacific coast of South America, feeding in the cold, nutrient-rich waters. Fishermen in Peru and Chile eagerly await the fishing season every year, but every now and then, it does not come as planned. This is one of those years.

Some years the easterly trade winds in the Pacific weaken or even reverse. The trigger for this remains uncertain, but it causes a warm ocean current to flow east to the coast of South America. This replaces the nutrient-rich cold water, causing the anchovies to disappear.

Because the warm waters arrive around Christmas time, Peruvian fishermen named the phenomenon El Nino de Navidad (The Christmas Child).

The impact of El Nino, a natural weather pattern, spreads much further than South America, and can bring drought or floods to millions in affected areas. This year it comes supercharged by climate change, which is worrying many scientists, governments and aid workers.

Stephanie Roe, lead climate scientist with the World Wildlife Fund (WWF), told Al Jazeera that this “super El Nino” is a stark reminder of how climate change can intensify pressures on both people and the natural world.

“El Nino can bring devastating climate extremes on its own, but it’s unfolding today on a much warmer planet, increasing the likelihood that heat, drought, floods and fires will push communities and ecosystems beyond anything they have experienced before,” Roe said.

As it develops in the Pacific, this year’s El Nino is combining with an ongoing, massive marine heatwave, further adding to the impacts of human-induced global warming. Its effects will be felt through food systems and biodiversity, impacting the livelihoods of fishermen and farmers, and the billions around the world reliant on the agricultural industry for their food.

El Nino’s development is being closely monitored from both space and sea, using satellites and a network of buoys. The devices in the Pacific Ocean continuously transmit data on ocean temperatures, currents and winds, helping scientists assess how powerful the event could become. Indications currently suggest the 2026-27 El Nino could be the strongest on record.

Research by the Met Office, the United Kingdom’s national weather and climate service, shows that a typical El Nino episode leads to temperature rises of between 1 and 2 degrees Celsius in the equatorial Pacific Ocean. But projections now indicate that when El Nino fully bites in late 2026 or early 2027, temperatures could spike by 3C.

“We should be clear this is an unprecedented event. I have never seen an El Nino signal this intense in our forecasts,” Adam Scaife, professor and the Met Office’s head of long-range forecasting, told Al Jazeera.

“This implies that if the forecast is accurate – and other forecast systems show similar extreme values – then this will far exceed our recent experience of El Nino and its worldwide climate influences,” Scaife said.

Scientists know that the weather is never certain, but an El Nino ramped up by global warming spells trouble. United Nations Secretary-General Antonio Guterres has compared it to “pouring fuel on the fire of a warming world”.

The effects will be felt by billions across the world, bringing droughts to some regions and severe flooding to others. In some cases, it can bring both.

Southeast Asia and South America will be particularly badly affected by this phenomenon, according to Carbon Brief, a United Kingdom-based website specialising in climate issues. There might be drought in Southern Africa, but flooding in the east of the continent. El Nino could also bring extreme heat that would weaken summer monsoons, leading to drought.

According to the World Meteorological Organization (WMO) Secretary-General Celeste Saulo, this super El Nino demands exceptional preparation and response. “Never before in the 50-year history of the WMO have we launched such a major mobilisation delivering forecasts and services to save lives and livelihoods,” she said.

El Ninos can reduce the number and size of Atlantic hurricanes and provide welcome rainfall to drought-stricken areas. Models indicate that the peak will be from December to February, which coincides with the main planting season and crop-development period in South America.

Investment bank Morgan Stanley said that wetter conditions could benefit agricultural yields in Argentina and southern Brazil, but other parts of Brazil might face more irregular rainfall and delayed planting.

Overall, the outlook is grim, with crop failures caused by El Nino and the climate crisis rippling through supply chains and leading to billions of dollars in damage to the global economy. One group of economists at Citigroup investment bank have estimated that a super El Nino could inflict as much as $7 trillion in global economic losses over five years, as its effects leave lasting scars on gross domestic product (GDP) growth.

“Most El Nino years are a nuisance, but this one has the makings of a shock, as weather patterns shift across key growing regions,” said Julia Rizzo, Morgan Stanley’s commodities strategist for Latin America.

“The effects may extend far beyond local forecasts and into supply chains, prices and investment returns.”

The World Food Programme (WFP) has warned that El Nino could hit as global food systems face systemic challenges due to high energy and fertiliser prices, brought about by the United States’ war on Iran.

“Together these factors increase the risk that climate shocks could push more people into hunger,” the WFP told Al Jazeera.

The United Nations agency forecasts that 274 million people will be facing acute hunger by the end of 2027, an increase of 49 million from current levels.

Outbreaks of disease, like malaria and dengue fever, could be another consequence, particularly in places where sanitation and health systems are already under pressure.

John Nairn, WMO’s senior extreme heat adviser, said extreme heat is the most direct concern.

“Where pre-existing drought exists, heatwaves intensify and compound other hazards such as water scarcity, dust, wildfires, smoke and flash floods,” Nairn said. “Each carries its own burden, ranging from heat mortality and respiratory impacts to waterborne disease.”

It is also feared that the compounding effects of El Nino will put highly stressed ecosystems under more pressure.

In the Pacific region, the loss of baitfish, including anchovies and sardines, is having a knock-on effect up the food chain and could cause deaths among seals and sea lions. Thousands of seabirds have also already washed up dead on Eastern Pacific coasts from California to Ecuador.

“Our recent surveys have been reporting seabird strandings and deaths every day, but it started to explode in June. It showcases the magnitude of this El Nino over such a large expanse of the Pacific,” said Sebastian Cruz of the American Bird Conservancy.

And perhaps most alarming of all for scientists is the likely increase in global temperatures.

“During large El Nino events, significantly more heat is released from the ocean to the atmosphere, leading to an increase in global average temperature,” said Met Office climate scientist Nick Dunstone. “So 2027 is very likely to replace 2024 as the hottest year on record.