2024 was officially the first year to pass the 1.5 deg C global warming limit, as overpopulation and human behaviour push the planet towards ‘climate breakdown’.

Despite world leaders vowing a decade ago that they would take the necessary avoidance steps, planet Earth has moved a major step closer to warming more than 1.5 deg C, new data shows.

The European Copernicus climate service, one of the primary global data providers, announced last week that 2024 was the world’s hottest calendar year on record, and the first to pass the symbolic 1.5 deg C threshold.

UN chief António Guterres described the recent run of temperature records as “climate breakdown”.

“We must exit this road to ruin – and we have no time to lose,” said Guterres in his New Year message, calling for countries to slash emissions of planet-warming gases in 2025.

Average global temperatures for 2024 were around 1.6 deg C above those of the pre-industrial period – the time before humans began burning large amounts of fossil fuels – according to Copernicus data.

This breaks the previous record set in 2023 by just over 0.1 deg C, and means the last 10 years are now the 10 warmest years ever recorded.

Last year’s heat is predominantly due to continued human population growth, and humanity’s emissions of planet-warming gases, such as carbon dioxide, which are still at record highs.

Samantha Burgess, deputy director of Copernicus, told the BBC: “By far and away the largest contribution impacting our climate is greenhouse gas concentrations in the atmosphere.”

The 1.5C figure has become a powerful symbol in international climate negotiations ever since it was agreed in Paris in 2015, with many of the most vulnerable countries considering it essential for survival.

“It’s not like 1.49 deg C is fine, and 1.51 deg C is the apocalypse,” Zeke Hausfather, a climate scientist at US research group Berkeley Earth, told the BBC. “Every tenth of a degree matters and climate impacts get progressively worse the more warming we have.”

In 2024, the world saw prolonged drought in parts of South America, blistering temperatures in west Africa, intense rainfall in central Europe and some particularly strong tropical storms hitting north America and south Asia.

According to the World Weather Attribution group, these events were just some of those made more intense by climate change over the last year.

These new temperature figures were released as Los Angeles has been overwhelmed with destructive wildfires fuelled by high winds and a lack of rain. And while there may be many contributing factors to these uncontrollable wildfires, experts agree that conditions conducive to fires in California are becoming more likely in a warming world.