The earth's climate experienced its hottest year in 2024. Extreme flooding in April killed hundreds of people in Pakistan and Afghanistan.
A year-long drought has left Amazon river levels at an all-time low. And in Athens, Greece, the ancient Acropolis was closed in the afternoons to protect tourists from dangerous heat.
A new report from the EU's Copernicus Climate Change Service confirms that 2024 was the first year on record with a global average temperature exceeding 1.5 degrees Celsius above pre-industrial levels.
All continents except Australasia and Antarctica experienced their hottest year on record, with 11 months of the year exceeding the 1.5 degrees Celsius level.
Global temperatures have been at record levels – and still rising – for several years now. The previous hottest year on record was 2023. All ten of the hottest years on record have fallen within the last decade. But this is the first time a calendar year has exceeded the 1.5 degrees Celsius threshold.
Scientists at Copernicus used reanalysis to calculate the temperature rises and estimate changes to extreme events. Reanalysis is produced in real-time, combining observations from as many sources as possible – including satellites, weather stations and ships – with a state-of-the-art weather forecasting model, to build up a complete picture of the weather across the globe across the past year.
The resulting dataset is one of the key tools used by scientists globally to study weather and climate.
Limiting sustained global warming to 1.5 degrees Celsius is a key target of the Paris agreement, the 2015 international treaty which aims to mitigate climate change.
The 195 signatory nations pledged to “pursue efforts” to keep long-term average warming below 1.5 degrees Celsius.
While reaching 1.5 degrees Celsius in 2024 is a milestone, surpassing 1.5 degrees Celsius for a single year does not constitute crossing the Paris threshold.
Year-to-year fluctuations in the weather mean that even if a single year surpasses 1.5 degrees Celsius, the long-term average may still lie below that.