The possible strong effects of El Niño predicted for 2023 – 04/28/2023 – Environment

The last time an El Niño formed was in 2016 — and its effects were felt around the world.

This weather phenomenon has contributed to record increases in global temperatures, the loss of tropical forests, coral bleaching, the generation of forest fires and polar melting ice.

Now scientists believe that the phenomenon will happen again – and warn of the possibility of a strong El Niño forming in the coming months. In addition, “sharp and unexpected” warming of the oceans is taking place – and, combined, these events could push global temperatures to record levels between 2023 and 2024.

But what do we know about this phenomenon and why is it worrisome?

EXTREME EVENTS

El Niño is a natural weather phenomenon — not caused by human activity — of which there are references since at least the end of the 19th century.

“El Niño is basically a change in the strength and direction of the trade winds blowing from east to west across the Pacific Ocean, which causes the warm water found in the western part of the Pacific Ocean to move towards the central and eastern Pacific region. “, explains Ángel Adames Corraliza, professor of atmospheric sciences at the University of Wisconsin, USA, to BBC News Mundo, the BBC’s Spanish-language news service.

But this is not a harmless change.

The expert claims that the movement of these warm waters causes a significant increase in ocean temperatures in the central and eastern Pacific area.

“High ocean temperatures are more conducive to heavy rains and flooding. And this has consequences for the hydrological cycle on the west coast of South America, especially in Peru and Ecuador. There are even direct effects on atmospheric circulation that cause changes in climatic conditions and climate in general both in North and South America and also in other parts of the world”, he says.

Adames says this raises concerns, mainly because a strong El Niño — like the one being predicted for this year — is usually associated with extreme weather events.

“We are talking about the possibility of seeing extreme weather events that don’t tend to happen normally, because El Niño basically changes the climate. So we see things that are not usual in different regions. That is cause for concern”, he observes.

This climatic phenomenon means that, for example, in regions that tend to be particularly rainy, such as northern Australia, droughts and fires occur; while in places like the west coast of South America, whose climate is dry and known for its deserts, heavy rains occur.

“The first impact you see is the warming of the coast of Peru. This year, if the record hasn’t been broken, it’s about to be. you have these very high temperatures, causing floods, landslides, deaths and terrible loss of material resources,” says Adames.

He explains that the development of El Niño, especially if ocean temperatures continue to rise, often leads to a more active hurricane season in the eastern and central Pacific.

“During El Niño years, there is an increased risk of hurricanes for the west coast of Mexico and Hawaii. We often see hurricanes or typhoons that cross the ocean, and more intense hurricanes occur in the southernmost region of the western Pacific Ocean. In contrast, hurricane activity in the Atlantic Ocean decreases,” he says.

Adames says that, although it is still being studied, there are indications that El Niño tends to cause droughts in the Caribbean during the summer in the northern hemisphere, affecting places like Cuba, the Dominican Republic and Puerto Rico.

At times, this drought can extend into Central America—from Panama to Honduras in particular—as well as causing heat waves in the Amazon region.

“In general, the impacts tend to be more of heat and drought for Latin America, but the biggest effects tend to occur on the western slopes of the Andes and in the mountains that predominate in Latin America. So, we are talking about Lima and all the large cities in that coastal region on the Pacific side of South America that tend to suffer major impacts in terms of rainfall and heat”, points out Adames.

REINFORCEMENT OF GLOBAL HEATING

Although El Niño has a natural origin unrelated to global warming caused by human activities, it can contribute to rising temperatures on the planet.

This weather phenomenon is characterized by a release of heat from the Pacific Ocean into the atmosphere, through which it is distributed.

“El Niño years tend to be warmer than normal, so if we have possibly a record El Niño this year, i.e. extremely strong, we’re talking about significant warming of the atmosphere that will add to the warming caused by human beings”, warns Adames.

“The second half of this year — and more likely next year — will be an extremely hot period, with lots of heat waves, because we’re talking about El Nino warming in addition to human-caused warming. So it’s possible that 2024 or the end of this year will be one of the hottest we’ve experienced since records have been made”, he adds.

The United States Weather Service (NWS) has issued an alert for El Niño, because there are indications that it is likely to develop in the coming months.

According to the NWS, there is a 62% chance that this phenomenon will develop between May and July of this year. They also estimated the probability of a “strong” El Niño at 40%.

Ángel Adames says that April is a very difficult time to anticipate the appearance of this phenomenon, but he pointed out that there are several signs that suggest that it will happen.

First, he points to the high temperatures recorded along the coast of Peru.

He explains that there are a series of buoys placed in the equatorial region of the Pacific to measure the temperature not only on the surface, but also in the depths of the ocean, and at this moment all of them indicate a warming that would be being registered from the coast of Peru until almost reaching the coast of New Guinea.

“So we’re talking about greater warming,” he observes.

A second indicator would be a change that occurred a few weeks ago in the westward direction of the trade winds.

“Normally, when the winds change direction, this accelerates the movement of warm water towards the eastern Pacific region, and this is a very strong indication that an El Niño is developing”, he points out.

The last indicator is the weather forecast models.

“Right now, the vast majority of them are indicating that we are heading for a strong El Niño”, he adds.

This text was originally published here.