Apart from being the warmest year on record, 2024 was the first calendar year when the average global temperature exceeded 1.5°C above the pre-industrial level, the Copernicus Climate Change Service (C3S) has said.

“2024 was the warmest year in global temperature records going 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,” C3S — implemented on behalf of the European Commission by the European Centre for Medium-Range Weather Forecasts (ECMWF) — said.

This temperature was 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 (2015–24) was one of the 10 warmest years on record.

Misery for millions

Carlo Buontempo, Director of the Copernicus Climate Change Service, ECMWF, said: “All of the internationally produced global temperature datasets show that 2024 was the hottest year since records began in 1850.”

Samantha Burgess, Strategic Lead for Climate, ECMWF, said: “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, said C3S. 

Human-induced

Human-induced climate change remains the primary driver of extreme air and sea surface temperatures; while other factors, such as the El Niño Southern Oscillation (ENSO), also contributed to the unusual temperatures observed during the year, said C3S.

 In 2024, ECMWF, NASA, the National Oceanic and Atmospheric Administration, the UK Met Office, Berkeley Earth and the World Meteorological Organisation (WMO), made a concerted effort to coordinate the release of their data, highlighting the exceptional conditions experienced during 2024, a C3S statement said.

The monthly global average temperature exceeded 1.5°C above pre-industrial levels for 11 months of the year. Going back further, all months since July 2023, except for July 2024, exceeded the 1.5°C level.

New daily record high

A new record high for daily global average temperature was reached on July 22, 2024, at 17.16°C.

2024 was the warmest year for all continental regions, except Antarctica and Australasia, as well as for sizeable parts of the ocean, particularly the North Atlantic Ocean, the Indian Ocean, and the western Pacific Ocean.

2024 saw three record-warm seasons for the corresponding time of the year: boreal winter (December 2023-February 2024), boreal spring (March-May) and boreal summer (June-August) at 0.78°C, 0.68°C and 0.69°C respectively above the 1991-2020 average.

Each month from January to June 2024 was warmer than the corresponding month in any previous year on record. Each month from July to December, except August, was the second warmest, after 2023, for the time of year. August 2024 was tied with August 2023 as the warmest on record.

Heat stress

In 2024, the annual average sea surface temperature (SST) over the extra-polar ocean reached a record high of 20.87°C, 0.51°C above the 1991–2020 average, said C3S.

In 2024, the El Nino weather event, which started in 2023, ended and the transition towards more neutral or La Nina conditions began.

C3S said the total amount of water vapour in the atmosphere reached a record value in 2024, at about 5 per cent above the 1991–2020 average — over 1 per cent higher than in 2016 and 2023, the years with the previous highest and second highest values, respectively.

Extreme temperatures and high humidity contribute to increased levels of heat stress. Much of the Northern Hemisphere experienced more days than average with at least “strong heat stress” during 2024, and some areas saw more days than average with “extreme heat stress”.

CO2, methane levels rise

In 2024, the area of the globe affected by at least “strong heat stress” reached a new record annual maximum on July 10, when around 44 per cent of the globe was affected by “strong” to “extreme heat stress”. This is 5 per cent more of the globe compared to the average annual maximum.

The European weather agency said the atmospheric concentrations of carbon dioxide and methane continued to increase and reached record annual levels in 2024, at 422 parts per million (ppm) and 1,897 parts per billion (ppb), respectively. Carbon dioxide concentrations in 2024 were 2.9 ppm higher than in 2023, whereas methane concentrations were 3 ppb higher.