Heat-trapping greenhouse gases and an El Nino weather pattern could push global temperatures to record levels in the next five years, a new update by the World Meteorological Organisation has found.

The report, published on Wednesday, notes there is a 70 per cent likelihood annual average global temperature between 2023 and 2027 will exceed 1.5 degrees above pre-industrial levels for at least one year. If temperatures do exceed this threshold, it will be the first time.

The chance of temporarily exceeding 1.5 degrees has risen steadily since 2015, when it was close to zero. For the years between 2017 and 2021, there was a 10 per cent chance of exceedance.

“This report does not mean that we will permanently exceed the 1.5-degree level specified in the Paris Agreement, which refers to long-term warming over many years. However, WMO is sounding the alarm that we will breach the 1.5-degree level on a temporary basis with increasing frequency,” the agency’s secretary-general Professor Petteri Taalas said.

“A warming El Nino is expected to develop in the coming months and this will combine with human-induced climate change to push global temperatures into uncharted territory,” he said. “This will have far-reaching repercussions for health, food security, water management and the environment,” said Taalas.

Early warning signs that an El Nino is looming lie in warming ocean temperatures. Last month, the world’s ocean surface reached an all-time high of 21.1 degrees, data from National Oceanic and Atmospheric Administration showed.

At least one of the next five years will be the warmest ever, the WMO report notes, exceeding the previous record set in 2016 which resulted in global sea and land temperatures 0.99 degrees warmer than average for the 1951-1980 benchmark. All but one of the 16 hottest years on record have occurred this century.

There is only a 30 per cent chance that the five-year mean will exceed the 1.5 degree threshold, according to the Global Annual to Decadal Climate Update produced by the United Kingdom’s Met Office, the WMO lead centre for such predictions.