Last year was the hottest on record and first to breach a key global warming threshold

Last year has been confirmed as the hottest on record, surpassing a crucial global warming marker of 1.5C above pre-industrial temperatures for the first time, according to scientists.

Data from the European Union's Copernicus Climate Change Service (C3S) cemented previous speculations, declaring 2024 as the warmest year globally ever recorded, noting it was also the first entire year the average temperature increased beyond 1.5C since pre-industrial times. Experts attribute human-induced climate change as the primary cause for such unprecedented temperatures but acknowledge that natural phenomena like the "El Nino" condition in the Pacific Ocean, known for boosting global temperatures, also played its part.

Further research by the Met Office, University of East Anglia, and the National Centre for Atmospheric Science aligns with these findings, indicating 2024 as the hottest year recorded with a likelihood of breaching the 1.5C mark. While climate specialists stress that a lone year’s average temperatures rising 1.5C above pre-industrial levels doesn't signify the world has hit this degree of global warming permanently, they raise alarms regarding the perilously close approach to this threshold.

The record-breaking warmth serves as a stark "reality check", alongside a year marked by severe weather events, highlighting the threats of living in a world with 1.5C of warming, remarked one expert. The global Paris agreement, forged in 2015, holds the central aim of preventing the planet from heating more than 1.5C above pre-industrial levels to dodge the most catastrophic effects of climate change.

According to a UK analysis, the global average temperature in 2024 reached 1.53C above the 1850-1900 average, with a margin of error of plus or minus 0.08C, marking it as likely the first year to exceed 1.5C. This also represents the eleventh consecutive year equalling or exceeding 1C above pre-industrial levels.

Colin Morice from the Met Office noted that a single year's reading does not constitute a breach of the Paris Agreement, which requires an average temperature of at least 1.5C over a longer period. He said: “A single year exceeding 1.5C above pre-industrial does not mean a breach of the Paris Agreement 1.5C guard rail – that would require a temperature of at least 1.5C on average over a longer period. However, it does show that the headroom to avoid an exceedance of 1.5C, over a sustained period, is now wafer thin.”

The Copernicus analysis estimated temperatures at 1.6C above the 1850-1900 pre-industrial level, an increase of 0.12C above 2023, previously the hottest year on record. Europe experienced its warmest year on record, with temperatures 1.47C higher than the 1991-2020 average, as reported. Moreover, the past decade has been among the ten warmest years recorded globally.

Samantha Burgess from the ECMWF's Copernicus Climate Change Service (C3S) said: "We are now teetering on the edge of passing the 1.5C level defined in the Paris Agreement and the average of the last two years is already above this level. These high global temperatures, coupled with record global atmospheric water vapour levels in 2024, meant unprecedented heatwaves and heavy rainfall events, causing misery for millions of people.”

UK climate minister Kerry McCarthy said: “Breaching the 1.5C target sends a clear signal: there is much more work to be done to keep 1.5C within reach and prevent climate catastrophe. The scale of the challenge is huge, but through collective action we can deliver change at the scale and pace required.”

She added: “Not only is this crucial for our planet, it is the economic opportunity of the 21st century. Through our clean energy superpower mission this government is showing what can be done – tackling the climate crisis while creating new jobs, delivering energy security and attracting new investment into the UK.”