Climate change added 41 days of dangerous heat in 2024, caused 'unrelenting suffering': WWA report

Human-caused climate change added an average of 41 days of dangerous heat in 2024, harming human health and ecosystems, according to a report by World Weather Attribution and Climate Central.

The analysis suggests 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 ofrelentless heatwaves, drought, wildfires, storms and floods.

Key findings of the report include:

● The world experienced an average of 41 extra days of dangerous heat in 2024 due to human-caused warming.

● Climate change intensified 26 of the 29 weather events studied by World Weather Attribution thatvkilled at least 3,700 people and displaced millions.

● Climate change had a stronger influence than El Niño on many extreme weather events.

Dr Friederike Otto, lead of WWA and Senior Lecturer in Climate Science at Imperial College London, said: "The impacts of fossil fuel warming have never been clearer or more devastating than in 2024. We are living in a dangerous new era.

“Extreme weather killed thousands of people, forced millions from their homes this year and caused unrelenting suffering. The floods in Spain, hurricanes in the US, drought in the Amazon, and floods across Africa are just a few examples.

"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.

”This year is set to be the hottest on record. The first six months saw record-breaking temperatures, extending the streak 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 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.

 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. The heat also fuelled heatwaves, droughts, fire weather, storms and heavy rainfall causing floods throughout the year.

 In total, 219 events met WWA’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 2000 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 fuelled Helene 200-500 times more likely and increased its devastating rainfall by 10%, the scientists found. Just two weeks later, the US southeast was hit again by Hurricane Milton and a rapid analysis found it was also intensified by fossil fuel warming.

Climate change is threatening irreversible changes to ecosystems, 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. 

Climate change made the hot, dry and windy conditions that drove the wildfires during June about 40% more intense, the scientists found. 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. When Risks Become Reality: Extreme Weather In 2024 is the first annual report published by WWA and Climate Central.

Julie Arrighi, Director of Programmes at the Red Cross Red Crescent Climate Centre, said: “Another devastating year of extreme weather has shown that we are not well prepared for life at1.3-1.5°C of warming.“Our studies continue to show the need to enhance preparedness for extreme weather to reduceloss of life and damages.

“In 2025, it's crucial that every country accelerate efforts to adapt to climate change.”

Ben Clarke, Researcher at the Centre for Environmental Policy, Imperial College London,said: "This annual report reads like a failed scorecard. "The world is not cutting emissions and preparing for climate change quickly enough. The consequences are record-breaking extreme weather events that cause deaths, displacement ,and loss of livelihoods.

"Of course, it doesn’t have to be like this. Investing in renewable energy and adaptation will make the world a safer, more sustainable place to live."

Joyce Kimutai, Research Associate at the Centre for Environmental Policy, Imperial College London, said: “Africa continues to bear the brunt of climate change. It has contributed the least emissions but is experiencing the worst impacts of extreme weather.

“This year was no different and African governments are having to reach deeper and deeper into their pockets to respond to disasters that are getting worse as the climate warms.

"In 2025, rich countries need to start delivering the climate finance they've promised to help Africa cope with extreme weather."

Joseph Giguere, research associate at Climate Central, said: "Almost everywhere on Earth, daily temperatures hot enough to threaten human health have become more common because of climate change.

"In many countries, residents are exposed to additional weeks' worth of heat reaching risk thresholds that would be virtually impossible without the influence of global warming."

Daniel Gilford, climate scientist at Climate Central, said: "Research shows that climate change is making hurricanes stronger. Human-caused ocean warming is boosting hurricane maximum wind speeds, allowing them to reach a full category higher, on average, which means they are more destructive than they would have been in a world without carbon pollution.”

Regina Rodrigues, Professor of Physical Oceanography and Climate, Federal University of Santa Catarina, said: “Severe droughts in the Amazon basin are becoming more frequent and severe due to climate change.

“We fear they might push the forest irreversibly to a drier state, leading to a reduction of moisture flow and carbon sink, as well as loss of biodiversity. ESN