Global temperatures increased by 1.6ºC above pre-industrial levels.in 2024, the first year that they have crossed the 1.5ºC threshold set by the global Paris Agreement.

Last year was the hottest since temperatures started being recorded in 1850, with a global average temperature of 15.1ºC. This was 0.12ºC hotter than 2023, the previous record-holder.

“Multiple global records were broken, for greenhouse gas levels, and for both air temperature and sea surface temperature, contributing to extreme events, including floods, heatwaves and wildfires,” according to the European Union’s Copernicus Climate Change Service (C3S) report for 2024, released on Friday.

“These data highlight the accelerating impacts of human-caused climate change,” according to the report released amid raging fires in Los Angeles in the US, fuelled by climate change.

About three-quarters of days in 2024 had air temperatures over 1.5°C above pre-industrial levels. There was also an increase in heat stress, which peaked on 10 July when around 44% of the globe was affected by ‘strong’ to ‘extreme heat stress’.

Europe recorded an increase of 1.47ºC (above 1991-2020 averages), its hottest year on record.

The annual average sea surface temperature (SST) over the extra-polar ocean reached a record high of 20.87°C, with  record highs across nearly one third (27%) of the extra-polar ocean.

Globally, the monthly average SST reached a new record in March of 21.07°C.

Warming covered vast regions of the Atlantic Ocean, most of the Indian Ocean, large parts of the Western Pacific, and portions of the Southern Ocean.

In Europe, record high SST were recorded in the central and eastern Mediterranean Sea, the Black Sea, and the Norwegian Sea.

The widespread occurrence of high SSTs led to a global coral bleaching event, declared by NOAA in April.

In contrast, the annual average SSTs across the eastern Pacific along the equator were close to the 1991–2020 average, reflecting a transition from El Niño conditions early in the year to La Niña conditions in the second half of the year.

The atmospheric concentrations of carbon dioxide and methane continued to increase and reached record annual levels in 2024.

Water vapour in the atmosphere also reached record levels in 2024, at 4.9% above the 1991–2020 average, which rom the enhanced greenhouse effect of additional water vapour in the atmosphere

For 10 years, every year has been hotter than the previous one and a 2018 report from the Independent Panel on Climate Change (IPCC) predicted that the world would only exceed 1.5ºC of heat by 2030.

However, the report noted that the limit set by the Paris Agreement “refers to temperature anomalies averaged over at least 20 years” so this had not yet been breached, but “it underscores that global temperatures are rising beyond what modern humans have ever experienced”. 

Human-induced heat

Although there was an El Niño in 2023–2024, a natural weather event that warms the sea surface, this was “strong but not exceptional event”, according to the report.

Instead, the past two years “appear to be exceptionally warm because of accelerating human-induced climate warming and an unusually warm phase of oceanic variability”,  according to the report.

“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,” said Copernicus director Carlo Buontempo.

“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,” Samantha Burgess, climate lead at the European Centre for Medium-Range Weather Forecasts (ECMRW)

“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.”

Image Credits: Unsplash, C3S/ECMWF.