The Copernicus Climate Change Service has confirmed that 2024 was the warmest year on record globally. It’s also the first calendar year that the average global temperature exceeded 1.5°C above its pre-industrial level.
Human-induced climate change remains the primary driver of extreme air and sea surface temperatures. Other factors, such as the El Niño Southern Oscillation (ENSO), also contributed to the unusual temperatures observed during the year.
2024 the hottest year on record
Carlo Buontempo, director of the Copernicus Climate Change Service at the European Centre for Medium-Range Weather Forecasts (ECMWF) confirmed: “All of the internationally produced global temperature datasets show that 2024 was the hottest year since records began in 1850. Humanity is in charge of its own destiny but how we respond to the climate challenge should be based on evidence. The future is in our hands – swift and decisive action can still alter the trajectory of our future climate.”
To highlight the exceptional conditions experienced during 2024, the organisations involved in global climate monitoring – ECMWF, NASA, NOAA, the UK Met Office, Berkeley Earth and the World Meteorological Organisation – coordinated the release of their information for the same time.
The global surface air temperatures shown above, highlight that 2024 was the warmest year in global temperature records that go back to 1850. The global average temperature of 15.10°C was 0.72°C above the 1991–2020 average, and 0.12°C above 2023, the previous warmest year on record. This is equivalent to 1.60°C above an estimate of the 1850–1900 temperature designated to be the pre-industrial level.
Each of the past 10 years (2015–2024) was one of the 10 warmest years on record. And in 11 of the 12 months of 2024, the monthly global average temperature exceeded 1.5°C above pre-industrial levels. Going back further, all months since July 2023, except for July 2024, have exceeded the 1.5°C level.
Climate conditions can influence extreme weather events
In 2024, extreme weather events were observed worldwide, ranging from severe storms and floods to heatwaves, droughts and wildfires. The increasing frequency and intensity of such events pose a significant risk to the livelihoods of people across the globe.
Prolonged dry periods in several regions created conditions conducive to wildfires. Large-scale and persistent wildfires were recorded across the Americas. In terms of wildfire carbon emissions, Bolivia and Venezuela recorded their highest levels on record, while Canada saw its second-highest levels, based on data from the Copernicus Atmosphere Monitoring Service.
As Samantha Burgess, strategic lead for climate at ECMWF, explained: “Each year in the last decade is one of the 10 warmest on record. We are now teetering on the edge of passing the 1.5ºC 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.”
With raging, out-of-control wildfires currently happening in Los Angeles, the direct impact of these climate extremes is shocking. Whether they are shocking enough for governments to take decisive action on the climate crisis remains to be seen.
The Paris Agreement not yet breached
Credit: C3S / ECMWF.
From the above graph on global surface air temperatures, we can note that both 2023 and 2024 were unprecedented. The first half of last year was particularly warm, with each month recording higher global temperatures than the same month in any previous year. This contributed to a 13-month streak of record-breaking monthly temperatures, which ended in June 2024.
From July onward, global temperature anomalies remained significantly above average. August 2024 was as warm as August 2023, and the other months from July to December ranked as the second-warmest on record, behind 2023. Notably, 22 July marked the hottest day ever recorded, with the global temperature reaching 17.16°C.
The persistence of exceptionally high monthly global average temperatures during the first half of 2024 made it likely, from late summer, that it would surpass 2023 as the hottest year on record. Furthermore, 2024 became the first year to register an annual temperature anomaly exceeding the 1.5°C threshold above the pre-industrial level. The two-year average for 2023/2024 also exceeds this threshold.
While this does not mean we have breached the limit set by the Paris Agreement – this refers to temperature anomalies averaged over at least 20 years – it underscores that global temperatures are rising beyond what modern humans have ever experienced.
Global warming moving faster than expected
The warming spike from 2023/2024 suggests an increase in warming rates, at least in the short term, as both years have deviated significantly from the long-term linear warming trend evidenced over the past 50 years. Uncertainty still remains around whether the short-term acceleration will become a longer-term trend.
“The abrupt new records set in 2023 and 2024 join other evidence that recent global warming appears to be moving faster than expected. Whether increased global warming is a temporary change or part of a new long-term trend remains to be seen”, said Dr Robert Rohde, lead scientist at Berkeley Earth. “Already though the Paris Agreement target of staying below 1.5°C is unobtainable, and the long-term average will pass this milestone within the next five to 10 years.”
High sea surface temperatures (SSTs) have been one of the most significant drivers behind the prevalence of high global temperatures in 2023 and 2024. One of the factors behind these high SSTs was the evolution of the ENSO. This peaked in December 2023 and continued to influence global temperatures in the first half of 2024.
What does this mean for the UK?
Professor Mark Smith, of the University of Leeds, told Yorkshire Bylines what the impacts to the UK could be, owing to these changing climate conditions.
“Thinking of the UK in particular, the intensification of the water cycle owing to the heating of the air (along with other climate changes) is evidently causing more frequent floods. Defences can be upgraded at a cost but eventually we’ll come to the point where we can’t keep up.”
2024 was the warmest year on record for Europe, with an average temperature of 10.69°C, which is 1.47°C above the average for the 1991–2020 reference period, and 0.28°C warmer than the previous record set in 2020.
With greenhouse gases continuing to increase and reaching record annual levels in 2024, at 422 parts per million, we remain on a very dangerous path. Carbon dioxide concentrations in 2024 were 2.9ppm higher than in 2023. If this rate continues, then within 30 years, we could reach a carbon dioxide concentration of 500 parts per million, almost double pre-industrial levels.
At some point, words like ‘record breaking’, ‘unprecedented’, ‘exceptional’, are not enough to describe this new world.
