May 2024 was the warmest May ever recorded, marking the 12th record-breakingly hot month in a row, Copernicus scientists have said.
Last month, the world's average temperature was 1.52°C higher than the average from 1850 to 1900, before industrialisation, according to the EU’s climate monitoring service.
It marks the 12th consecutive month where temperatures have been hotter than ever recorded with the global average surface air temperature 0.65°C higher than the average from 1991 to 2020.
“It is shocking but not surprising that we have reached this 12-month streak. While this sequence of record-breaking months will eventually be interrupted, the overall signature of climate change remains and there is no sign in sight of a change in such a trend,” says Carlo Buontempo, director of Copernicus Climate Service (C3S).
What is La Niña and how could it follow El Niño?
The increased heat in the ocean is a reflection of this unusually warm period.
In 2023, the oceans surrounding Europe experienced the highest average sea surface temperature on record, as reported by the World Meteorological Organization (WMO).
Since last July, the El Niño weather phenomenon has contributed to a rise in global temperatures and extreme weather worldwide - but scientists maintain that human-induced global warming was the primary driver.
However, the WMO reports that the 2023/24 El Niño is showing signs of ending and may be followed by La Niña conditions starting in June.
La Niña is distinguished by cooler-than-average sea surface temperatures in the central and eastern equatorial Pacific, typically resulting in weather patterns that are the opposite of those associated with El Niño, particularly in tropical regions.
This cooling is accompanied by alterations in the tropical air circulation, including modifications in wind patterns, air pressure and rainfall.
What does La Nina mean for global warming?
El Nino and La Nina typically begin in the spring or summer in the Northern Hemisphere.
The transition from the warm phase of El Nino to neutral or the cooler phase of La Nina occurs, on average, every three to five years.
However, this transition does not signal a change in the ongoing trend of global warming.
“Every month since June 2023 has set a new temperature record - and 2023 was by far the warmest year on record,” says WMO Deputy Secretary-General Ko Barrett.
“The end of El Nino does not mean a pause in long-term climate change as our planet will continue to warm due to heat-trapping greenhouse gases. Exceptionally high sea surface temperatures will continue to play an important role during the next months."
The last nine years have been the hottest on record, even with a multi-year La Niña cooling things down from 2020 to early 2023.
“Our weather will continue to be more extreme because of the extra heat and moisture in our atmosphere,” says Ko Barrett, who is leading a WMO delegation at the ongoing UN Climate Change Conference in Bonn.
“La Nina conditions generally follow strong El Nino events, and this is in line with recent model predictions, although high uncertainty remains regarding its strength or duration.”
