Climate change-fuelled extreme weather events in 2025 across the world pushed millions close to the “limits of adaptation”, finds a leading global report, affecting vulnerable and marginalised populations disproportionately.
The report. by International World Weather Attribution, founded in 2014 by climate scientists Friederike Otto and Geert Jan van Oldenborgh and the non-profit Climate Central, attempts to analyse climate events in detail, going beyond broad phenomena.
The 2025 report identifies a total of 157 events across the world that met its “trigger” criteria.
Unique criteria
The report has “unique criteria” specific to the distinct impacts of every hazard type: floods, storms, droughts, heatwaves, fires and cold spells. “For example,
our threshold for floods is met if any of the following criteria are met: more than 100 deaths, more than a million people affected, more than 50% of total population affected, or a declaration of state of emergency or disaster on national or state level. These thresholds ensure the methodology captures the most impactful events around the world,” the report says. “In 2025, a total of 157 events met our trigger criteria, with triggers for floods (49) and heatwaves (49) occurring more frequently, followed by storms (38), wildfires (11), droughts (7) and cold spells (3). From these, we studied 22 events (Figure 1), comprising 3 in Africa, 7 in the Americas, 5 in Asia, 6 in Europe and 1 in Oceania,” it adds.
Detailed climate analysis
The report analyses in detail the precise impact of climate change on weather phenomena. For example, it examines the effect of climate change on the 7-day extreme heat situation that Sudan experienced in February 2025.
A series of charts show Sudan’s comparable temperature “before climate change” — 36 degrees Celsius; ,“today at 1.3 degrees Celsius of warming” — at 40 degrees Celsius, and the projected with 2.6 degrees Celsius of warming — at 42 degrees Celsius.
Several deaths were caused due to the heat, directly and indirectly.
The report also present’s how often Sudan experienced such an event before and after climate change. Before climate change it was a 1 in a 1600-year event; today it is a 1 in a 2-year event and around 2100, with 2.6 degrees Celsius warning, it is likely to be a yearly occurrence.
Similarly, for Hurricane Melissa, the
most devastating cyclone of 2025 that had a landfall in Jamaica, the report says that the landfall maximum windspeed increased by 5 metres/second. The hurricane caused 102 deaths.
Asia disasters
In Asia, the report focuses on the floods in Pakistan, Sri Lanka and Indonesia, and on the drought in Central Asia, particularly Iran.
“Global temperatures were exceptionally high throughout the year. Although natural modes like El Niño Southern Oscillation were in a cooler phase, global warming made 2025 one of the warmest years on record,” says the report. “Heatwaves have become measurably more intense since the Paris Agreement was signed, with some events now up to ten times more likely to happen than in 2015,” it adds.
The year 2025 shows the increasing risks “already present” at approximately
1.3°C of anthropogenic warming and argue for the compelling need to transition from fossil fuels, the report underlines.
“Each year, the risks of climate change become less hypothetical and more brutal reality,” said Friederike Otto, Professor in Climate Science at the Centre for Environmental Policy at Imperial
College London and co-founder of World Weather Attribution.
Data inequality
Even as the most vulnerable parts of the world bear the biggest impact of extreme weather events, the same inequality is reflected in climate science, with less data being available on these areas and climate
models having restrictions.
India, according to other analyses, was amongst the worst affected by extreme weather events.
The Delhi-based think tank Centre for Science and Environment (CSE) published an analysis stating that in India, extreme weather was recorded on 331 of the 334 days in the first 11 months of 2025. The figures had shot up from 295 days in 2024 and 292 in 2022.
Due to these events, at least 4,419 deaths had occurred in 2025, a sharp rise from 3,006 such deaths in 2022.
India events
Extreme weather events in India included heatwaves, coldwaves, lightning, storms, cyclones, cloudbursts, heavy rainfall, floods and landslides.
“2025 showed us that we are now in a persistent new era of dangerous, extreme weather. This year we have also seen a slide into climate inaction, and the defunding of important climate information initiatives,” said Theodore Keeping, Researcher at Imperial College London. “The evidence of the severe, real impacts of climate change are more clear than ever, and it is
essential that action is taken to stop fossil fuel emissions, and to help the world’s most vulnerable to prepare for the devastating impacts of increasingly extreme weather,” Keeping added.
“There is nothing in natural climate models that can explain why 2025 was this hot. While factors like El Niño can cause temporary fluctuations in global temperatures, they still don’t explain the sustained warmth we saw this year,” said Sjoukje Philip, Researcher at the Royal Netherlands Meteorological Institute.
“The continuous rise in greenhouse gas emissions has pushed our climate into a new, more extreme state, where even small increases in global temperatures now trigger disproportionately severe impacts,” Philip added.