Goodbye to the El Niño phenomenon, although La Niña will not be a great relief | The boy

Bloomberg — The record temperatures of 2023 have been due in part to the El Niño phenomenon in the Pacific Ocean.

The positive is that El Niño is quickly giving way to its colder sister, La Niña. The negative is that she won’t exactly be kinder to human beings.

El Niño and La Niña are two stages of a local climate phenomenon, the El Niño-Southern Oscillation (ENSO), which influences conditions across the planet.

In 2015-16, a strong El Niño event generated unprecedented global temperatures, deadly droughts and floods, a surge of cyclones in the Pacific, and the largest coral reef bleaching event in history, to name just a few of its consequences. .

While the now-moribund El Niño of 2023-24 was one of the strongest on record, it was noticeably weaker than the 2015-16 El Niño. However, its global effects were even more alarming: 12 successive months of heat records around the world, ocean temperatures reaching places where no maps exist.

Why has this El Niño period been much more devastating, despite having less strength? The answer rhymes with ““shlimate shange”.

To simplify a lot, El Niño tends to warm the planet, while La Niña tends to cool it. Now, the background temperature of the planet is 1.3° Celsius warmer than in pre-industrial times, due to our efforts to burn fossil fuels. This makes El Niño more capable of wreaking havoc.

Persistent global warming also makes it less likely that the impending arrival of La Niña will bring much, if any, relief.

There is still a strong chance that 2024 will be the hottest year on record, even if half of it takes place under cooler La Niña conditions.

“The end of El Niño does not mean a pause in long-term climate change, as our planet will continue to warm due to heat-trapping greenhouse gases,” the deputy secretary-general of the World Meteorological Organization (WMO) said on Monday. , for its acronym in English), Ko Barrett, in a statement.

The WMO noted that the last nine years have been the warmest in the world even though several of them have been spent under La Niña conditions.

In fact, the Pacific Ocean’s ENSO pattern has been in a neutral or La Niña phase for more than 17 of the past 30 years, doing little more than temporarily slowing the inexorable rise in global temperatures.

To add insult to injury, La Niña phases also tend to increase the frequency of Atlantic hurricanes by dampening “wind shear,” or the change in air temperature as it rises or falls.

Between an incipient La Niña and ocean temperatures that remain staggeringly high, scientists expect a hurricane-filled summer and fall in the Atlantic.

The National Oceanic and Atmospheric Administration recently predicted that there could be up to 25 named storms and up to 7 “major” hurricanes this season, which began June 1 and continues through November 30.

Unfortunately, in recent years meteorologists have tended to underestimate the number of storms that actually occur. And warmer ocean water and higher sea levels produced by climate change tend to make hurricanes more intense and destructive.

It was bad enough during the centuries when El Niño and La Niña simply beat the entire planet’s climate back and forth like a badminton birdie. Once humans became involved in climate manipulation, they proved to be even more powerful and destructive, just on a longer time scale.

The advantage is that humans also have the power to change their impact, moving away from the fossil fuels that are making the planet hotter. In the meantime, we must continue to adapt to the weather that is becoming increasingly chaotic no matter which side of the net the birdie is on.

This note does not necessarily reflect the opinion of the editorial board or of Bloomberg LP and its owners.

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