El Niño is already causing high surface air temperatures around the world – but 2024 will see it jump to ‘the next level’, a scientist has warned.
Kevin Trenberth, of the University of Auckland in New Zealand, warned that early 2024 could see frequent temperatures of 1.5C above pre-industrial levels.
The World Meteorological Organization (WMO) confirmed this month that the El Niño weather pattern emerged in the tropical Pacific for the first time in seven years.
El Niño is an event where temperatures in the Pacific are warmer than normal – it’s declared when temperatures rise 0.5C above the long-term average.
It’s part of a cycle alongside the ‘opposite’ effect, La Niña, which has been active for the last three years.
Temperatures around the world increase by about 0.2C during El Niño, and fall about 0.2C during La Niña.
Campaigners and observers have warned this year that the return of El Niño could push the world past crucial climate change barriers.
The world's hottest year on record, 2016, coincided with a strong El Niño – though experts say climate change has fuelled extreme temperatures even in years without the phenomenon.
Even that record could soon be broken, according to the WMO.
The organisation said in May that there was a strong likelihood that at least one of the next five years, and the five-year period as a whole, would be the warmest on record due to El Niño and anthropogenic global warming.
Trenberth wrote in The Conversation, ‘With a new El Niño emerging and prospects that it could be another major event, are we about to experience the next step up the stairs?
‘Already in 2023, sea-surface temperatures emerged in April as the highest on record and values are running 0.℃ above previous highs.
‘This set the stage for June to have record high surface air temperatures globally. In early July, they hit the highest values on record.
‘We can expect 2023 to emerge as the warmest year to date. But sea-surface temperatures during El Niño events tend to peak about December and have the greatest influences in the subsequent two months.
"That sets the stage for 2024 jumping up the staircase to the next level, perhaps to 1.4C above pre-industrial levels, with likely daily incursions over 1.5C.
‘Once the next La Niña event comes along, there'll again be a pause in the rise, but values will never quite go back to previous levels.’
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