In 2016, the current hottest year on record, an "El Nino" climate pattern in the Pacific pushed up sea temperatures and therefore global temperatures on top of global warming trends. In recent years, the Pacific has seen the opposite cooling "La Nina" effect - but this is set to end.
Next year is forecast to be one of the hottest years on record and even warmer than 2022, experts have said.
Met Office scientists estimate that 2023 will be the 10th consecutive year in which global temperatures will be at least 1C above pre-industrial levels, measured as the period from 1850 to 1900.
The current hottest year on record is 2016, a year that saw an "El Nino" climate pattern in the Pacific, pushing up sea temperatures and therefore global temperatures on top of global warming trends
In recent years, the Pacific has experienced the opposite effect, "La Nina", which has kept temperatures lower.
However, this is set to come to an end, says Dr Nick Dunstone, who has led the Met Office's 2023 global temperature forecast.
"The global temperature over the last three years has been influenced by the effect of a prolonged La Nina - where cooler than average sea-surface temperatures occur in the tropical Pacific," he said. "La Nina has a temporary cooling effect on global average temperature.
"For next year our climate model is indicating an end to the three consecutive years with La Nina state, with a return to relative warmer conditions in parts of the tropical Pacific.
"This shift is likely to lead to global temperature in 2023 being warmer than 2022."
The Met Office's forecast predicts global average temperatures in 2023 will be around 1.2C above what they were before humans started to drive climate change.
Last year, experts predicted 2022's global temperature would be between 0.97C and 1.21C above pre-industrial levels, with a central estimate of 1.09C. Data for the year to October suggests the temperature is around 1.16C above the pre-industrial era.
At the COP27 climate summit, held in Sharm el-Sheikh, Egypt, in November, countries agreed a historic dedicated fund to help vulnerable nations hit by climate disasters, but failed to step up efforts to tackle the damaging emissions that cause them.
Professor Adam Scaife, the Met Office's head of long-range prediction, said that while 2023 might not break the 2016 record it will likely see further high temperatures.
"Without a preceding El Nino to boost global temperature, 2023 may not be a record-breaking year, but with the background increase in global greenhouse gas emissions continuing apace it is likely that next year will be another notable year in the series," he said.
Dr Doug Smith, a climate prediction expert for the national weather service, said some parts of the world had seen greater increases than others.
"The fact that global average temperatures are at or above 1C for a decade masks the considerable temperature variation across the world," he said.
"Some locations such as the Arctic have warmed by several degrees since pre-industrial times."
Original source: Sky News