“These extraordinary extremes could be an early warning of tipping points towards different weather or sea ice or fire regimes,” said University of Exeter climate researcher Tim Lenton. “We call it ‘flickering’ when a complex system starts to briefly sample a new regime before tipping into it. Let’s hope I’m wrong on that.”

In the meantime, the tropical Pacific Ocean is shifting into the warm El Niño phase of a two- to seven-year Pacific Ocean cycle that can boost the average global temperature by 0.2° Celsius, enough to stoke the planet’s fever to a dangerous new high.

“The onset of El Niño will greatly increase the likelihood of breaking temperature records and triggering more extreme heat in many parts of the world and in the ocean,” said World Meteorological Organization Secretary-General Petteri Taalas. “Early warnings and anticipatory action of extreme weather events associated with this major climate phenomenon are vital to save lives and livelihoods.”

“I expect a step change to higher global mean temperatures starting this year,” said atmospheric scientist Kevin Trenberth, a distinguished scholar at the National Center for Atmospheric Research and honorary faculty at the University of Auckland. “And next year will be the warmest on record, either 1.4 or 1.5C above pre-industrial.”