UN warns of 'supersized' El Niño as countries prepare for impact

The world has entered a "danger zone of extreme weather" as the impacts of El Niño start to be felt globally, UN head António Guterres has warned.

The World Meteorological Organization (WMO) has released the latest data on the natural weather phenomenon showing it could be the strongest for more than 70 years and last until at least February 2027.

El Niño changes weather patterns around the world, pushing some regions into drought whilst others experience stronger typhoons and flooding.

Forecasters also say El Niño will boost temperatures in some places, coming on top of rising heat globally from human-induced climate change.

"El Niño is being supersized before our eyes. The science leaves no room for doubt: the planet is in uncharted waters, and those waters are heating up," Guterres said.

The BBC spoke with governments and scientists about the measures being taken globally to reduce the risk of deaths, displacement and environmental damage. Early warning systems have been strengthened and deployment of pre-emptive medical assistance, but the strength of this particular event has raised serious concerns particularly for vulnerable groups.

The WMO - a UN agency - said it has undertaken a "major mobilisation" to try to circulate its forecasts of potential extreme weather events, linked to El Niño, to as many communities as possible.

WMO Secretary-General Celeste Saulo warned: "El Niño has the potential to deliver a massive blow to communities and economies across the world."

El Niño is a natural weather phenomenon that develops in the Pacific Ocean and is linked to a change in wind patterns. It allows warm water to spread eastwards and releases heat into the atmosphere.

Sea temperatures in the central and eastern tropical Pacific have risen sharply in recent months - a clear sign of a strengthening El Niño.

In the Pacific's key monitoring region, surface temperatures have been well over 2C above average in recent weeks, putting it on track to be declared a "very strong" event.

But it is expected to surpass even that marker. Monthly sea surface temperatures could get close to 4C above average, forecasts suggest.

This would make it the strongest El Niño since at least 1950, by potentially a large margin.

Temperatures are even more exceptional below the surface of the Pacific - in places more than 8C above average.

Above-normal sea temperatures are also expected in other parts of the world including the Indian Ocean, tropical Atlantic and around parts of the Australian coast.

With its rich marine life, changes in ocean heat are of particular concern to Australia.

It has been plagued by marine heatwaves in recent years - driven by climate change - leading to widespread coral bleaching and algae blooms, causing "unprecedented damage".

El Niño is a natural phenomenon, but it tends to bring the kind of extreme heat which also drives those disasters, Dr Alistair Hobday, chief researcher at Australia's science agency, told the BBC.

This year, marine heatwave forecasts indicate the Great Barrier Reef will be spared the worst of the conditions, giving coral there more time to recover.

"[But] Southern Australia is getting slammed. It had an algal bloom last year, it's got bird flu now, and it looks like marine heatwaves will be stronger there this summer," said Hobday.

Last time a marine heatwave hit South Australia and Tasmania, there were starving penguins, fish kills, suffocating algae outbreaks, and jellyfish invasions.

Australia has recently introduced early warning systems for marine crises - this gives time for financial relief for fisheries to be established, relocation of crucial species and increased coral monitoring.

But this event is shaping up to be unprecedented - and Hobday admits he is quite worried.

Reduced rainfall brings drought and trade disruption

While the impacts on global weather are likely to be felt well into 2027, the WMO expects significant changes in rainfall patterns over the next few months.

Drier-than-usual conditions are forecast across large areas of South East Asia, Central America and northern parts of South America, increasing the risk of droughts and wildfires.

On Thursday, the number of vessels passing through the Panama Canal will be reduced by more than 10% in anticipation of lower rainfall.

About 14,000 ships per year use the artificial waterway - as well as being a crucial route for global trade, it is also a key source of income for Panama, bringing in about $3bn (£2.2bn) a year.

Indonesia is racing to contain wildfires that have burned more than 107,000 hectares of land nationwide this dry season. Like some other parts of South East Asia, it is facing a longer season this year.