El Niño is coming Droughts, floods and heat threaten many regions of the world

It's bad news for many regions of the world: the El Niño weather phenomenon is on its way, with more droughts, more floods and more heat. What does this mean for Europe?

DPA

04.07.2023, 07:37

02.06.2026, 10:38

dpa

In the man-made climate crisis, the average global temperature is rising steadily, with devastating consequences. The hottest year since the beginning of industrialization was 2016, and that is no surprise: in addition to the long-term trend, 2016 was characterized by the weather phenomenon El Niño . It occurs naturally every few years and often pushes up the global average temperature.

Since this spring, the signs of an El Niño have been increasing again - and if it comes and becomes strong, the global average temperature could top 2016 as early as this year or next, experts warn. The World Meteorological Organization (WMO) wanted to explain on Tuesday whether El Niño is fully underway or not.

What is an El Niño?

The first sign of the phenomenon is a strong warming of the upper layers of water in the Pacific Ocean near the tropics, along the Central and South American coast. Actually, trade winds push the warm water to the west and cooler water flows in from deeper layers. In El Niño situations, however, the winds are weaker.

The fast, band-shaped jet stream shifts to the south and the stratosphere more than ten kilometers above the earth becomes warmer, as Bob Leamon from the University of Maryland explains.

The counterpart to this is La Niña, with the opposite sign. La Niña puts pressure on the global average temperature. An unusually long three-year La Niña phase has just come to an end. Both phenomena occur at different intervals every few years.

Where does the name come from?

"El Niño" translates as the Christ child. The name comes from fishermen in Peru who often noticed the rise in sea temperature at Christmas time.

What are the consequences?

It depends on the region of the world. It generally gets drier and hotter in South East Asia, southern Africa and Australia, for example. The risk of forest and bush fires increases there. In Australia, the hottest summer ever recorded was the turn of the year 2018/2019, which was characterized by an El Niño.

It is also getting drier in Brazil and the northern part of South America, as well as in the Midwest of the USA, where grain harvests are often particularly good in El Niño years. On the other hand, it is getting wetter in East Africa, which has just gone through a devastating drought, as well as on the west coast of North and South America and in Sri Lanka off the southern tip of India.

In the Gulf of Mexico, the risk of hurricanes is decreasing because there is less moisture in the air. Over the Atlantic, too, because stronger wind shear is tearing hurricanes apart, says Leamon. In the Pacific, on the other hand, there is a risk of more dangerous storms.

And Europe? "El Niño's fingerprint is concentrated in the tropical Pacific, with noticeable effects on the greater Pacific region and along the equator, but with only minor effects in Europe," says Helge Gössling from the Alfred Wegener Institute Helmholtz Center for Polar and Marine Research (AWI) in Bremerhaven.

What triggers an El Niño?

Science does not yet know. It is considered a natural phenomenon like the monsoon, but it occurs at irregular intervals. What is known is that the strength of both El Niño and La Niña is influenced by other phenomena. When the trade winds normalize over the course of the year, as they did in 2014, an incipient El Niño can dissipate, as climate scientist Michelle L'Heureux from the US climate agency NOAA explains.

John Fasullo from the National Center for Atmospheric Research in the US state of Colorado believes that the fact that the most recent La Niña event lasted so long was partly due to the severe fires in Australia in 2019/20. Smoke aerosols in the atmosphere reflected sunlight, which cooled layers of air over the Pacific and subsequently the sea surface.

Why does the global average temperature rise in El Niño years?

Climate scientist Richard Allan from the University of Reading has investigated this. On the one hand, satellite images and computer simulations from 2015/16 showed that more low clouds dissolved over the Pacific and more sunlight warmed the water.

In addition, the atmosphere held significantly more water than in other years. During strong El Niños, this could amount to 3,000 cubic kilometers of water, as much as 120 million 50-meter swimming pools. "This helps to further increase the heating power of El Niño, as water vapor is a powerful natural greenhouse gas," says Allan.

Is the goal of limiting warming to a maximum of 1.5 degrees as far as possible in danger due to the approaching El Niño?

The target is in danger, but it's not because of El Niño. It's about different things. The 1.5 degree target from the Paris Climate Agreement - which experts say is almost impossible to achieve - refers to an average value over several years.

Individual warmer years, which are now more likely due to El Niño, are not decisive for this. Even before the first signs of an El Niño, many scientists assumed that the 1.5 degree limit would soon be exceeded in a single year.

After that, cooler years are likely to follow. According to the WMO, the global average temperature in 2022 was around 1.15 degrees above the level of 1850-1900, compared to around 1.3 degrees in 2016.

How strong will the El Niño be in 2023?

Hard to say. Leamon from the University of Maryland concludes from his model calculations that the phenomenon is more likely to fizzle out this year and that a super El Niño is not imminent until 2026.

What does this mean for the global economy and people?

According to calculations by US economists, the El Niños of 1982/83 and 1997/98 each resulted in losses of up to 4.1 trillion dollars within five years - compared to a development without the weather phenomenon. The Economist Intelligence Unit sees a strong El Niño this year as a major risk for agricultural and fish production in South and Southeast Asia. This would drive up food prices.

Higher temperatures could lead to energy bottlenecks and shutdowns there. This would then affect industrial production. In Sri Lanka, heavier rain could affect tea production, while the humidity could also lead to more cases of dengue fever. The analysis institute Fitch Solutions warns of a slump in the grain harvest in southern Africa.