However, this does not imply a permanent breach of the 1.5-degree Celsius limit specified in the Paris agreement, as it refers to long-term warming over many years. Every month since June last year has been the warmest such month on record.

Scientists attribute the exceptional warming to the combined effects of El Ni?o -- a period of abnormal warming of surface waters in the central Pacific Ocean -- and human-caused climate change. The global average temperature in January was 1.66 degrees Celsius above the January average for 1850-1900, the designated pre-industrial reference period.

With an average temperature of 13.14 degrees Celsius, January 2024 was 0.12 degrees Celsius warmer than the previous warmest January in 2020, the Copernicus Climate Change Service (C3S) said.

Scientists at C3S said the global mean temperature for the past 12 months (February 2023-January 2024) was the highest on record and 1.52 degrees Celsius above the 1850-1900 pre-industrial average. In 2015, countries agreed in Paris to limit the average temperature rise to well below 2 degrees Celsius, and preferably to 1.5 degrees Celsius, compared to pre-industrial levels (1850-1900), to avoid worsening climate impacts.

Multiple reports suggest that the world is significantly off track to limit global warming to 1.5 degrees Celsius. To achieve this goal, countries together need to cut down the emissions of planet-warming greenhouse gases like carbon dioxide and methane by 43 per cent by 2030.

Samantha Burgess, Deputy Director of C3S, said that "2024 starts with another record-breaking month -- not only is it the warmest January on record but we have also just experienced a 12-month period of more than 1.5 degrees Celsius above the pre-industrial reference period".

"Rapid reductions in greenhouse gas emissions are the only way to stop global temperatures from increasing." The year 2023 was the warmest on record, with the average global temperature rise compared to pre-industrial levels nearing the 1.5-degree Celsius threshold.

The World Meteorological Organisation in December said 2024 could be worse as "El Nino typically has the greatest impact on global temperature after it peaks."