Even with a normal El Niño, the effects are immense: floods on the west coast of South America and severe droughts and forest fires in Indonesia and Australia (symbolic image).Image: keystone
The forecasts have come true: El Niño is here. The phenomenon is driving ocean temperatures to new record levels. And it could get much worse.
Jul 2, 2026, 01:37Jul 2, 2026, 01:37
Matti Hartmann / t-online
One An unprecedented heat wave has hit the world’s oceans: Surface temperatures as high as this year have never been measured at the beginning of summer. On June 21, the measurements from the EU climate program Copernicus were 20.86 degrees Celsius and the Copernicus marine service was 21.0 degrees Celsius, above the previous record values for this day from 2023 and 2024.
According to NASA, the data currently being measured is partly similar to that from 1997. At that time, according to the World Bank, 23,000 people died as a result of natural disasters, the poverty rate rose by up to 15 percent in particularly affected countries and the subsequent economic costs amounted to around 45 billion US dollars.
The cause has also already been identified: the natural climate phenomenon El Niño, which is exacerbating the effects of the man-made climate crisis. Experts fear that this year’s El Niño could develop into a massive Super El Niño with devastating consequences.
Worrying NASA measurements
“At the moment it looks like this is going to be a huge deal,” said NASA researcher Severine Fournier at the end of June. She bases her statement on data from the Sentinel 6 satellite “Michael Freilich”. As early as spring 2026, this satellite began recording warm water waves hundreds of kilometers wide traveling from the western to the eastern Pacific.
According to NASA, the heat accumulation under the water surface is recorded by measuring the sea surface height. The principle behind it: The warmer water associated with El Niño displaces colder water in the upper layer of the ocean – and this leads to sea level rise due to the greater extent.
“Much more relevant”: That’s why sea level height is so important
According to NASA scientists, measuring sea surface height goes beyond simply measuring surface temperature. Because it also shows how much heat is stored below the surface. According to NASA, this is important because a thin, warm surface layer may have a lesser impact on the climate and weather, whereas a large heat reservoir beneath the surface could be “significantly more relevant”.
The German Max Planck Society also fears that the current El Niño could develop into a particularly strong phenomenon by the end of the year, even if the strength of an El Niño can only be reliably predicted at the end of the summer.
This is how El Niño works
Normally, trade winds in the Pacific drive surface water from east to west. On the way, the water is heated by the sun, so it arrives warmed in Southeast Asia. Off South America, however, cold, nutrient-rich water comes from the depths to the surface. Every few years, El Niño disrupts this system: the air pressure conditions change, the trade winds blow weaker or even change. Now the water off South America is warming, evaporation is increasing and heavy rain, floods and landslides are occurring. Meanwhile, El Niño has the opposite effect in Southeast Asia: There is a threat of drought and forest fires caused by the severe dryness.
Description of the El Niño climate phenomenon.Image: wikimedia
An event like 1997 – or even worse?
What is certain, however, is that the consequences would be massive. Even with a normal El Niño, the effects are immense: floods on the west coast of South America, severe droughts and forest fires in Indonesia and Australia, more strong hurricanes in the Pacific and cold late winters in Europe.
A strong El Niño would intensify precipitation and storms, as both depend heavily on the surface temperature of the sea, according to the Max Planck Society.
According to NASA, the data currently being measured is partly similar to that from 1997. At that time, according to the World Bank, 23,000 people died as a result of natural disasters, the poverty rate rose by up to 15 percent in particularly affected countries and the subsequent economic costs amounted to around 45 billion US dollars.