Climate change caused 41 extra dangerous heat days in 2024, the annual review by World Weather Attribution (WWA) and Climate Central revealed on Friday.
The organisations calculated how many such days there were in 2024 and compared that to a world in which there would have been no climate change. They found that, on average, there were 41 extra days in 2024.
However, that global average gives a somewhat distorted picture. Small island states such as Nauru, Barbados and Saint Vincent and the Grenadines were particularly affected, with more than 150 extra dangerous heat days. Belgium had "only" 26 extra days.
In any case, 2024 will go down in history as the warmest year ever recorded, with temperatures for the first time 1.5°C higher than pre-industrial levels. This is significant, as the 1.5°C threshold is the lower limit in the Paris Climate Agreement – a legally-binding commitment signed by almost every nation. Still, one year at +1.5°C does not mean that the Paris target is now beyond reach.
Besides being exceptionally warm, 2024 was also marked by exceptional rainfall. This is largely because warmer air can hold more moisture. Additionally, the warming of the oceans causes more water to evaporate and therefore more rain to fall.
The two organisations mapped extreme rainfall by comparing the five wettest consecutive days since 1994. This showed that in 2024, the heaviest rainfall was recorded in central Europe, parts of Australia, the south-eastern United States and the Sahel region.
Climate Central also calculated that each hurricane became stronger last year due to climate change, resulting in higher wind speeds and more damage.
Demonstrable change
2024 was an "exceptional year for extreme weather", both organisations concluded. WWA registered 219 phenomena that met the criteria to be analysed, of which 29 were closely studied. In 26 cases, the extreme weather phenomena were found to have worsened as a result of climate change. Together, these were responsible for 3,700 deaths.
"As 2024 draws to a close, this report underlines that the demonstrable damage caused by man-made climate change is not a distant threat but a contemporary reality," said Friederike Otto, a climatologist at Imperial College London and founder of WWA.
The report also includes four recommendations to better protect society from extreme weather phenomena and the impacts of climate change by 2025: a faster exit from fossil fuels, developing better early-warning systems, more accurate reporting of heat-related deaths, and international funding to help developing countries better cope with climate-related disasters.