One of the next five years could be the warmest on record. This is what the World Weather Organization (WMO) predicted in its publication on Wednesday “Global Annual to Decadal Climate Update”. In addition, the 1.5 degree mark could be exceeded globally for the first time on an annual basis. The El Niño period, which the organization expects in the coming months, plays an important role in this. El Niño is a weather phenomenon in the equatorial Pacific that leads to higher temperatures worldwide and favors extreme weather in many regions of the world.
The El Niño forecast for 2023 and 2024 is not decisive for the fact that the next five years will probably be the warmest five-year period, clarified climate researcher Helge Goessling from the Helmholtz Center for Polar and Marine Research in Bremerhaven. “The El Niño forecast increases the already high probability of an upcoming five-year record even further.” The probability that an El Niño will develop is 70 for the period June to August and 80 for July to September percent, the WMO announced at the beginning of May.
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Is a Super El Niño looming?
El Niño is centered in the tropical Pacific, Goessling pointed out. This means that the weather phenomenon will have the greatest noticeable effects on the greater Pacific region and along the equator. The situation is different in Europe: “There is no strong connection between the development of temperatures in Europe and the fluctuations in the globally averaged temperature caused by El Niño,” he explained.
How pronounced the El Niño period will be is unclear. It can be moderate or strong, but in the worst case it could also be a Super El Niño. The US Climate Prediction Center currently indicates the probability of a strong El Niño in the months of June to August at around 50 percent. “So we can almost certainly expect a moderate to strong El Niño event next autumn and winter,” concluded Andreas Fink, Professor of Meteorology at the Institute for Meteorology and Climate Research at the Karlsruhe Institute of Technology.
Depending on how strong the El Niño phase becomes and how far it drags into the coming year, 2024 could become the warmest year in the world. However, the forecasts should be treated with caution: “An estimate at this point in time remains uncertain,” said Fink. In all likelihood, more reliable forecasts will not be possible until June. That is when El Niño usually peaks.
La Niña has been cooling earth for three years
The fact that a new global temperature record is more likely not in this year but in the coming year is due to La Niña – the counterpart to El Niño. The cold phase of a cycle of ocean and wind currents in the tropical Pacific lowers the average global temperature but also encourages extreme weather. The most recent La Niña period started in the winter of 2020/2021 and continued until last winter, so the world is currently in a “neutral phase”. One of the triggers for La Niña was the Australian bushfires, as a study recently found out.
Study: Australian bushfires may have cooled earth for years
Fires continue to heat the earth. But they can also do the opposite, a study from the USA now proves. For example, the extreme bushfires in Australia in 2019/2020 could have been the cause of a rare multi-year La Niña event. But why?
“Even with continued La Niña conditions, the long-term global warming trend would now end this warming pause within the next few years,” Goessling said. The earth would therefore continue to heat up even without the upcoming El Niño phase. “Despite the La Niña event of the past three years, the global mean temperature was on a very high plateau and we were in the range of the warm years of the past El Niño phase,” agreed climatologist Karsten Friedrich from the German Weather Service. “The actually cooling effect of La Niña has almost not been shown.”
Target of the Paris climate agreement not yet missed
Consequently, the 1.5 degree mark is now on the brink. According to the WMO, the probability that the global temperature will rise above 1.5 degrees for the first time in the years 2023 to 2027 compared to the pre-industrial level is more than 60 percent. When that will happen cannot be predicted. Exceeding this limit would initially only be limited to a single year. So it cannot be ruled out that cooler years will come again, and the goal of the Paris climate agreement has not yet been missed. “The average global temperature will only have exceeded the 1.5-degree mark around the years 2032 to 2035,” predicted Karsten Haustein, a researcher in the Atmospheric Radiation Department at the Institute for Meteorology at the University of Leipzig. The global mean is currently 1.25 degrees.
The climatologist Friedrich would not be surprised if the 1.5-degree mark was briefly exceeded. After all, the highest atmospheric CO₂ values were ever measured in the spring, he pointed out. It was 423 parts per million. And greenhouse gas emissions are still at a high level and are even increasing in some cases. “I also think it’s possible that the 1.5-degree target will be broken in the long term in the next few years,” says Friedrich, “even if exceeding the 1.5-degree mark for a short time is priced into the target paths.”