Last month was the world\u2019s warmest January on record raising further questions about the pace of climate change, scientists say.<\/p>\n
January 2025 had been expected to be slightly cooler than January 2024 because of a shift away from a natural weather pattern in the Pacific known as El Ni\u00f1o.<\/p>\n
But instead, last month broke the January 2024 record by nearly 0.1C, according to the European Copernicus climate service.<\/p>\n
The world\u2019s warming is due to emissions of planet-heating gases from human activities \u2013 mainly the burning of fossil fuels \u2013 but scientists say they cannot fully explain why last month was particularly hot.<\/p>\n
It continues a series of surprisingly large temperature records since mid-2023, with temperatures around 0.2C above what had been expected.<\/p>\n
\u201cThe basic reason we\u2019re having records being broken, and we\u2019ve had this decades-long warming trend, is because we\u2019re increasing the amount of greenhouse gases in the atmosphere,\u201d Gavin Schmidt, director of Nasa\u2019s Goddard Institute for Space Studies, told BBC News.<\/p>\n
\u201cThe specifics of exactly why 2023, and 2024, and [the start of] 2025, were so warm, there are other elements involved there. We\u2019re trying to pin those down.\u201d<\/p>\n
January 2025 ended up 1.75C warmer than January temperatures of the late 19th Century, before humans started significantly warming the climate.<\/p>\n
Early last year, global temperatures were being boosted by the natural El Ni\u00f1o weather pattern, where unusually warm surface waters spread across the eastern tropical Pacific. This releases extra heat into the atmosphere, raising global temperatures.<\/p>\n
This year, La Ni\u00f1a conditions are developing instead, according to US science group Noaa, which should have the opposite effect.<\/p>\n
While La Ni\u00f1a is currently weak \u2013 and sometimes takes a couple of months to have its full effect on temperatures \u2013 it was expected to lead to a cooler January.<\/p>\n
\u201cIf you\u2019d asked me a few months ago what January 2025 would look like relative to January 2024, my best shot would have been it would be cooler,\u201d Adam Scaife, head of monthly to decadal predictions at the UK Met Office, said.<\/p>\n
\u201cWe now know it isn\u2019t, and we don\u2019t really know why that is.\u201d<\/p>\n
A number of theories have been put forward for why the last couple of years have been warmer than anticipated.<\/p>\n
One idea involves a prolonged response of the oceans to the 2023-24 El Ni\u00f1o.<\/p>\n
While it was not especially strong, it followed an unusually lengthy La Ni\u00f1a phase from 2020-23.<\/p>\n
The El Ni\u00f1o event might therefore have \u201clifted the lid\u201d on warming, allowing ocean heat that had been accumulating to escape into the atmosphere.<\/p>\n