Global temperatures soared to a new record in September by a huge margin, stunning scientists and leading one to describe it as “absolutely gobsmackingly bananas”.

The heat is the result of the continuing high levels of carbon dioxide emissions combined with a rapid flip of the planet’s biggest natural climate phenomenon, El Niño.

Mika Rantanen, climate researcher at the Finnish Meteorological Institute, said: “I’m still struggling to comprehend how a single year can jump so much compared to previous years.” Prof Ed Hawkins, at the University of Reading, UK, said the heat seen this summer was “extraordinary”.

Samantha Burgess, at the EU’s Copernicus Climate Change Service, said: “The unprecedented temperatures for the time of year observed in September have broken records by an extraordinary amount.

These include an uptick in the 11-year solar cycle, cuts in sun-blocking sulphur emissions from shipping and industry and a volcanic eruption in Tonga that released a large amount of water vapour, which traps heat.

Increasingly severe weather impacts had also been long signposted by scientists, although the speed and intensity of the reality and the unexpected vulnerability of many populations scared some.

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