Search Climate Insights Directory

A World Weather Attribution study examines the role of climate change and natural variability in the devastating floods of November 2025 across Sri Lanka and the Malacca Strait. While observational data indicate a significant increase in the intensity of extreme 5-day rainfall events—up to 160% in Sri Lanka and 50% in the Malacca Strait due to a 1.3°C rise in global temperatures—climate models failed to consistently capture these trends, preventing a definitive quantitative attribution. The study also notes that La Niña and a negative Indian Ocean Dipole contributed between 5% and 13% to the rainfall in the Malacca Strait, while rapid urbanization and infrastructure failures exacerbated the humanitarian impact.

A super-rapid attribution study by World Weather Attribution finds that human-induced climate change has significantly increased the likelihood and intensity of a five-year drought in Iran and the Tigris-Euphrates basin. The analysis shows that while low-rainfall years are natural to the region, the current 'extreme' to 'exceptional' drought conditions would have been very rare in a pre-industrial climate. The study highlights that warming increases evaporative demand, prolonging droughts and compounding the effects of socio-economic stressors like unsustainable groundwater extraction and water-intensive agriculture.

An event attribution study on the October 2025 floods in eastern Mexico found that the onset of La Niña heightened the likelihood and intensity of heavy rainfall. While climate models and observational datasets showed conflicting trends regarding the long-term impact of climate change on regional rainfall, the study emphasizes that vulnerability was amplified by rapid urbanization, informal settlements, and chronic underinvestment in indigenous and rural communities.

Hurricane Melissa, a Category 5 storm, caused widespread destruction and 61 deaths across Jamaica, Haiti, and the Dominican Republic in October 2025. Analysis indicates that climate change increased the likelihood of the extreme conditions that fueled the storm by a factor of about 6 and increased the intensity of associated rainfall by more than 9%. In Jamaica, 5-day rainfall events are now about 30% more intense and twice as likely, while in eastern Cuba, intensity increased by 50% and frequency by a factor of 9. The storm's maximum wind speeds are estimated to be approximately 7% more intense due to warming. Despite financial risk strategies like catastrophe bonds, damages in Jamaica are estimated to be at least an order of magnitude larger than available finance.

The report highlights that while projected warming has decreased from 4°C in 2015 to 2.6°C today, this level of warming still results in significantly more frequent and intense heat days. It notes that extreme heat waves have become more likely since 2015, with some events now 10 times more likely. Despite the expansion of early warning systems, the report argues that adaptation finance is insufficient to keep pace with the rising costs of inaction on extreme heat.

The 2025 fire season in Spain and Portugal saw extreme burned areas, with Spain experiencing its worst fires in 30 years and Portugal burning 260,000 ha. These events coincided with the most intense heatwave on record in Spain. Analysis indicates that a 1.3°C increase in global temperatures since preindustrial times has made these extreme fire-conducive weather conditions approximately 40 times more likely, transforming an event that would have occurred once every 500 years into one expected every 15 years.

A research paper by World Weather Attribution finding that climate change made the extreme fire weather conditions of 2025 in Türkiye, Greece, and Cyprus approximately 10 times more likely and significantly more intense.

A research analysis by World Weather Attribution finds that human-induced climate change made a July 2025 heatwave in Norway, Sweden, and Finland approximately 2°C hotter and at least ten times more likely than in a preindustrial climate. The event caused significant strain on healthcare systems, disrupted reindeer grazing and Sámi livelihoods, and led to increased drowning deaths and wildfires. The report highlights that current winter-focused building designs in the Nordic region are inadequate for rising temperatures and that similar heatwaves are now twice as likely as they were during the previous major event in 2018 due to a global warming increase from 1.1°C to 1.3°C.

An event attribution study by World Weather Attribution found that human-induced climate change, primarily from fossil fuel combustion and deforestation, has increased the intensity of 30-day maximum rainfall in northern Pakistan by approximately 15%. The study highlights that while the event had a return period of about five years, the resulting high death toll—300 fatalities nationwide as of August 3, 2025, including 140 children—was exacerbated by rapid urbanization, informal settlements, and poor building code enforcement. The report emphasizes a significant funding gap for adaptation, noting that Pakistan requires US$152 billion for adaptation between 2023 and 2030, much of which remains unfinanced.

The study analyzed rainfall events in Colombia and Venezuela, finding that the June 2025 floods were not meteorologically extreme, with return periods of 10 and 3 years respectively. While some data suggests a slight decrease in rainfall likelihood and intensity in a cooler climate, high uncertainty remains due to model disagreement and a lack of high-quality in-situ weather data in northern South America. The report emphasizes that vulnerability is exacerbated by informal urbanization, deforestation, and socio-economic instability, necessitating increased investment in weather monitoring and climate resilience to manage both droughts and intense downpours.

A rapid analysis by World Weather Attribution finds that climate change made a June 2025 heatwave in southeast England approximately 2-4°C more intense, increasing the likelihood of such an event from once every 50 years to once every 5 years. The report highlights that early-season heatwaves are particularly dangerous due to a lack of human acclimatisation and that the UK's building stock, designed for heat retention, exacerbates indoor overheating. While the Heatwave Plan for England provides a foundation for response, the Climate Change Committee notes that heat-related policies remain fragmented and lack long-term targets.

An attribution study of heavy rainfall in coastal New South Wales from May 19-22, 2025, found mixed results regarding the influence of climate change. While observational data suggests a doubling in likelihood for the wettest four-day annual event in a 1.3°C warmer climate, climate models show substantial disagreement on rainfall trends for the region. The study emphasizes the need for flexible adaptation strategies due to this uncertainty.

An event attribution study found that human-induced climate change increased the likelihood of the April 2025 extreme rainfall in the Central Mississippi river valley by approximately 40% and its intensity by 9%, though observational data suggests these increases could be as high as a factor of 2 to 5 in likelihood and 13-26% in intensity. The event caused at least 24 fatalities and estimated economic damages between $80 and $90 billion, with significant agricultural losses in Arkansas. The study highlights that while climate change amplified the event, effective early warnings from the US National Weather Service prevented a larger catastrophe, despite current staffing shortages in NWS field offices.

A study by World Weather Attribution found that human-induced climate change made a March 2025 heatwave in Central Asia approximately 4 °C hotter and three times more likely. The event saw temperatures exceeding 30 °C even at 1000m altitude, affecting regions including Kazakhstan, Uzbekistan, Turkmenistan, Tajikistan, and Kyrgyzstan. The analysis notes that climate models underestimate the recent increase in March temperatures, meaning the reported influence of climate change is a conservative estimate. The heatwave coincided with critical agricultural periods, such as the sowing of spring wheat in Kazakhstan and the flowering of export fruit crops, potentially impacting yields in a region where agriculture employs up to 50% of the workforce.

A World Weather Attribution analysis finds that human-induced climate change made the extreme heat in South Sudan in February 2025 at least 2C hotter and at least 10 times more likely. The report highlights that women and girls bear disproportionate impacts due to their roles in agriculture and unpaid care work, as well as systemic inequalities in education and health. The study notes that extreme heat exacerbates malnutrition for 860,000 children under five and increases risks for 1.1 million people in overcrowded shelters due to conflict.

The study finds that human-induced warming from burning fossil fuels made peak January Fire Weather Index (FWI) conditions 35% more probable and 6% more intense. It also notes that the dry season has lengthened by approximately 23 days, increasing the overlap between available fuel and the Santa Ana winds. While climate models show varying results on precipitation trends, the overall evidence indicates that climate change has increased the likelihood of devastating fires in the region, with disproportionate impacts on elderly, disabled, and lower-income populations, including Black residents in Altadena.

The report finds that human-induced climate change significantly increased the frequency and intensity of extreme heat globally from May 2024 to May 2025, affecting billions of people and making all 67 identified significant heat events more likely. It highlights the disproportionate impact on vulnerable populations and the systemic failure to accurately document heat-related mortality, while advocating for a combination of urban heat action plans and aggressive fossil fuel mitigation.

The document reports that human-induced warming of 1.3°C contributed to record-breaking temperatures, floods, and droughts in 2024, resulting in thousands of deaths and millions of displacements. It highlights that climate change added an average of 41 dangerous heat days globally and often overrode natural phenomena like El Niño. The report calls for a rapid transition from fossil fuels, improved early warning systems, real-time heat death reporting, and increased finance for developing countries to support adaptation.

A study by scientists from the Philippines, UK, and Netherlands found that human-induced climate change, primarily from burning fossil fuels, increased the likelihood of the potential intensity observed during the 2024 late typhoon season in the Philippines by a factor of 1.7. The analysis focused on the sequence of six storms hitting northern Luzon, including Super Typhoon Man-Yi, and found that the probability of at least three major typhoons making landfall in a single year has increased by 25% in the current 1.3°C warmed climate compared to a world without fossil fuel combustion.

A rapid analysis by World Weather Attribution indicates that heavy 1-day rainfall events in central and southeastern Spain are approximately 12% more intense and twice as likely in the current climate, which is 1.3°C warmer than preindustrial levels. The analysis focuses on the extreme precipitation event of October 29, 2024, which caused devastating floods in regions like Valencia and Catalonia, resulting in over 200 deaths. While the study used daily rainfall data over a large region—potentially underestimating the intensity of localized sub-daily extremes—the findings align with the Clausius-Clapeyron relationship and existing evidence of climate change signals in European rainfall extremes.