Climate change added 41 days of dangerous heat in 2024 and caused 'unrelenting suffering'
The world experienced an average of 41 extra days of dangerous heat in 2024 due to human-caused warming, new analysis has found.
The report by World Weather Attribution (WWA) and Climate Central reviews a year of extreme weather and warns that every country needs to prepare for rising climate risks to minimise deaths and damages in 2025 and beyond.
It also highlights that a much faster transition away from fossil fuels is needed to “avoid a future of relentless heatwaves, drought, wildfires, storms and floods”.
The report also found that climate change intensified 26 of the 29 weather events studied that killed at least 3,700 people and displaced millions.
"The impacts of fossil fuel warming have never been clearer or more devastating than in 2024,” says Dr Friederike Otto, lead of WWA and Senior Lecturer in Climate Science at Imperial College London.
"We know exactly what we need to do to stop things from getting worse: stop burning fossil fuels. The top resolution for 2025 must be transitioning away from fossil fuels, which will make the world a safer and more stable place.”
Millions of people were exposed to dangerous heat in 2024
This year is set to be the hottest on record - the first six months saw record-breaking temperatures, extending the streak that started in 2023 to 13 months, with the world’s hottest day in history recorded on July 22.
Globally, there were 41 extra days of dangerous heat in 2024 due to human-caused warming, the scientists found.
These days represent the top 10 per cent of warmest temperatures from 1991-2020 for locations around the world.
The result highlights how climate change is exposing millions more people to dangerous temperatures for longer periods of the year as fossil fuel emissions heat the climate.
“Extreme weather killed thousands of people, forced millions from their homes this year and caused unrelenting suffering,” says Otto.
If the world does not rapidly transition away from oil, gas and coal, the number of dangerous heat days will continue to increase each year and threaten public health, the scientists say.
Human-induced warming is triggering extreme weather events
The heat also fueled heatwaves, droughts, fire weather, storms and heavy rainfall, causing floods throughout the year.
In total, 219 events met World Weather Attribution’s trigger criteria used to identify the most impactful weather events.
The team of scientists studied 29 of these events and found clear evidence of climate change in 26. The floods in Sudan, Nigeria, Niger, Cameroon, and Chad were the deadliest event studied by the group, with at least 2,000 people killed and millions displaced.
If warming reaches 2°C, which could happen as early as the 2040s or 2050s, the regions could experience similar periods of heavy rainfall every year, the study found, highlighting how climate change is making some events a ‘new normal’.
Hurricane Helene left 230 people dead across six states in the US, making it one of the deadliest mainland US hurricanes in the last 50 years, second only to Hurricane Katrina in 2005.
Climate change made the high sea temperatures that fueled Helene 200-500 times more likely and increased its devastating rainfall by 10 per cent, the scientists found.
Climate change is threatening irreversible changes to ecosystems, as an analysis of the Amazon drought highlighted, which found the event was 30 times more likely.
The Amazon is crucial for the stability of the global climate, but human-caused warming is pushing the forest towards a drier state, which could see massive tree dieback and the release of large amounts of carbon dioxide into the atmosphere.
Further south, the Brazilian Pantanal wetland, a biodiversity home to endangered species found nowhere else on earth, experienced one of its worst wildfire seasons ever.
The hot, dry and windy conditions that drove wildfires in June were also made about 40 per cent more intense by climate change, the scientists found.
Global warming caused more harm than El Niño in 2024
Many extreme events at the start of 2024 were influenced by El Niño. However, most WWA analyses found that climate change had a larger impact than El Niño in driving these events, including the historic drought in the Amazon.
This aligns with the broader trend that as the planet continues to warm, the effects of climate change are increasingly dominating over other natural factors that influence the weather.
The report sets out four resolutions for 2025 to both tackle climate change and protect people from extreme weather: a faster shift away from fossil fuels, improvements in early warning, real-time reporting of heat deaths, and international finance to help developing countries become more resilient.