In the 1600s, fishers in Peru saw that every few years around Christmastime, the waters there warmed, and they caught fewer anchovies. They called this 鈥淓l Ni帽o鈥� 鈥� the boy 鈥� after the Christ child.

In the early 20th century, the physicist Gilbert Walker noticed that the prevailing low atmospheric pressure and rainy weather over the western Pacific and dry, high pressure over the eastern Pacific periodically flipped. But it wasn鈥檛 until 1969 that meteorologist Jacob Bjerknes linked the two, showing that swells of warm water in the Pacific Ocean end up wreaking havoc on weather across the globe.

Under normal conditions, the sun鈥檚 heat and Earth鈥檚 spin fuel east-to-west trade winds around the tropics, which blow water into a 鈥渨arm pool鈥� near Indonesia. As this warm pool grows, it builds up energy. 鈥淚t could be a bit like a coiled spring waiting to emerge,鈥� says at the University of Reading, UK.

Every two to seven years, natural chaotic disturbances release that spring. Bursts of westerly winds can blow against and slow the easterly trade winds, allowing swells of warm water to across the Pacific Ocean, raising sea levels along the coasts of Peru, Colombia and Ecuador. These so-called Kelvin waves indicate that El Ni帽o is coming.

A self-reinforcing cycle called the kicks in. The blob of warm water suppresses the upwelling of cold, nutrient-rich deep water that normally makes Peru鈥檚 anchovy fishery so rich, further warming the surface water. The warm sea heats the air above it and causes it to expand. The resulting fall in atmospheric pressure slows the trade winds down even more, since winds flow from high to low pressure. This allows still more warm water to slosh back into the eastern Pacific.

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The swathe of warm water stretching across the tropical Pacific releases trillions of joules of heat energy into the atmosphere, raising worldwide temperatures on top of global warming. This is why scientists expect 2027 to be the hottest year on record. But it also drastically alters weather patterns, bringing drought and wildfires to some areas and storms and flooding to others.

Normally, warm air rises over the warm pool, carrying moisture that falls out in thunderstorms, which is why rainforests flourish in places like Indonesia. Denuded of moisture, this warm, dry air then reaches the top of the troposphere and spreads out to the east and west. It descends over the eastern Pacific and the Horn of Africa, fuelling a belt of such air loops around the tropics called the Walker circulation.

During El Ni帽o, however, the warming of the eastern Pacific moves this upward convection eastward, shifting the entire Walker circulation. Now dry, warm air that was sinking over the Horn of Africa and the eastern Pacific is sinking over Indonesia and the Amazon, encouraging drought and wildfires there. Over eastern Africa, warm air is rising, increasing rainfall and the risk of flooding.

Meanwhile, the warming waters also create a stronger temperature contrast between the tropical and northern Pacific, strengthening the jet stream and bringing more storms and wet weather to the southern US. It can bring storms and rain to the UK as well, in certain circumstances.

鈥淚f this deep convection in the atmosphere moves around, it changes things locally, but it also then starts to change the whole circulation of the atmosphere,鈥� says at the European Centre for Medium-Range Weather Forecasts. 鈥淭hat鈥檚 why El Ni帽o is a big deal, not just some local process.鈥�

Emergency briefing on the nature and climate crisis

Hear from three of the world鈥檚 leading climate scientists at New 女生小视频 Live 2026

鈥淎 giant asteroid strike, global warming, a new plague, or nanomachines going rogue and turning everything into grey goo.鈥� This was a list of the biggest threats we faced, as predicted by a feature to mark New 女生小视频鈥檚 60th birthday in 2016. 鈥淎nother threat is artificial intelligence,鈥� we wrote. At least we dodged the asteroid (if only just).

As we prepare to celebrate the big 7-0 in a little under two months鈥� time (you may have noticed we鈥檝e had a little glow-up for the occasion), those threats may feel familiar, but the challenges we face as individuals and as society are even more pressing.聽

2016 was the year that the Paris Agreement went into force, with the ambition of limiting global warming to 1.5掳C above pre-industrial levels. In 2024, the planet breached that line for a full calendar year for the first time. With a powerful El Ni帽o on top of an already warmer planet, 2026 is set to surpass that record, accompanied by heatwaves, wildfires, landslides and other catastrophic events.

A decade ago, Donald Trump鈥檚 election was shocking, but his second term has seen stronger anti-science rhetoric than ever, driving not only cuts to funding but also dangerous misinformation 鈥� in particular with regard to health and the 别苍惫颈谤辞苍尘别苍迟.听

As for AI, it seems we are in a moment of reckoning. In a recent turn of events, even those developing it now warn that the technology could threaten humanity itself, one, its effects are already here, changing everything from the way we work and warfare to the way that people get their news.

For many publishers, this last point poses an existential risk in itself, with audiences increasingly turning to pre-digested AI summaries and social media pundits for their information, and no news publisher is immune.

Yet at a time when science, truth and journalism are all under threat from multiple directions, the importance of science journalism, and especially the high-quality, trusted and sceptical brand of journalism that New 女生小视频 was built on, is stronger than ever.

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There are many more reasons for optimism, too. The past 70 years have seen transformational changes in medicine, green technologies that can help us live more sustainably, and astonishing advances in our understanding of the universe. We will celebrate many of these in our anniversary coverage in the coming weeks, along with our predictions for what the biggest breakthroughs of the future will look like. We鈥檒l also be sharing life-affirming stories from readers, some of whom have been with us from the very beginning.

And let鈥檚 not forget the fun 鈥� this is a birthday, after all. The party begins properly in under two weeks, when tens of thousands of you descend on London for our annual event, , which turns 10 this year.

As for the rest of the year, and the next one, and the one after that: none of us can truly predict what the future holds, but whatever is in store, we plan to still be covering it in 2096. New 女生小视频 may be turning 70, but retirement is firmly off the cards.聽聽

Emergency briefing on the nature and climate crisis

Hear from three of the world鈥檚 leading climate scientists at New 女生小视频 Live 2026

Most climate impacts are like repeatedly shooting ourselves in the foot: we keep emitting greenhouse gases, the planet warms and more heatwaves happen, and wildfires, and flooding, and drought. Science tells us that this is mechanistic: pull the trigger and you will get hurt.

The collapse of the AMOC would be catastrophic. How will we know when it鈥檚 coming?

Europe faces incredibly harsh winters and unrelenting droughts if the vital AMOC ocean current fails 鈥� but when disaster will strike and how bad it will be remains uncertain. Now there is an ambitious plan to give us a warning

But in some cases, large uncertainty remains. One particular concern is the Atlantic Meridional Overturning Circulation (AMOC), the system of currents that transport a tremendous amount of heat from the Gulf of Mexico to Europe. As ever more icebergs and meltwater from Greenland rush into the north Atlantic, the AMOC is thought to be slowing down. Eventually it could even collapse, bringing 鈥渋ce age鈥� winters to Europe, raising sea levels in North America and disrupting vital monsoons in Africa and Asia.

Will that happen? We don鈥檛 know. Some research says the AMOC could cross a tipping point in centuries, some says decades and some says it has crossed it already. If we start reducing emissions, it may not happen at all. 女生小视频s have long described it as low probability but high impact. You might think of it as climate Russian roulette.

女生小视频s have long described the AMOC鈥檚 collapse as low probability but high impact

To tackle this uncertainty, scientists are trying to build an early warning system to alert us that the AMOC is going to cross a tipping point. It is unclear whether that warning would give us enough time to avoid this, or merely to prepare for the impacts, but both are better than doing nothing, which is what we are doing now. We may not know the probability of the AMOC collapsing, but we know it is increasing.

So far, the uncertainty around it has been an excuse to ignore it, or treat it as a distant problem. In fact, the uncertainty makes it even more important for policy-makers to take action now, in the same way we fund militaries for wars we hope will never come. Whether we decide to invest in mitigation or adaptation, we won鈥檛 regret it, since all of it will help with our bigger climate problem. Stop emissions, take the gun away and no one needs to get hurt.