Search Climate Insights Directory

The report finds that human-induced climate change increased the intensity and likelihood of heavy rainfall associated with Hurricane Milton in central Florida. Using the IRIS model, the analysis indicates that climate change increased the frequency of storms with Milton's wind speeds by approximately 40%, meaning the storm would have likely made landfall as a Category 2 rather than a Category 3 hurricane without global warming. Additionally, sea surface temperatures along Milton's track were 1°C warmer than in a world without climate change, making such temperatures 400 to 800 times more likely. The report also assesses Florida's adaptation measures, noting that while building codes are among the toughest in the US, the state's planning remains largely reactive and fails to adequately address social vulnerabilities in low-income and minority communities.

The study assesses the 2018 heatwave in Northern Europe using observational data and climate models to determine the role of human-induced warming. It finds that the probability of such an event has increased across the region, with the most significant increases in probability estimated in Ireland, Denmark, and the Netherlands. While the heat was most extreme in the high Arctic (northern Finland), where it exceeded historical records, the risk ratio was more easily quantified in southern regions. The authors conclude that anthropogenic climate change made these heatwaves more likely, though the exact magnitude of the increase is harder to quantify in Scandinavia due to high natural variability.

The report investigates the May 2022 extreme rainfall event in Eastern Northeast Brazil, which caused 133 deaths and displaced over 25,000 people. Observational analysis indicates that 7-day and 15-day rainfall events of this magnitude are exceptionally rare in the current climate, with return periods of approximately 1-in-500 and 1-in-1000 years, respectively. While climate models exhibited systematic errors in precipitation magnitudes for this specific event, the authors conclude that human-caused climate change is at least partially responsible for increasing the likelihood and intensity of such rainfall. The study further highlights that structural vulnerabilities, including unplanned urbanisation in low-income neighbourhoods and an infrastructure deficit, significantly exacerbated the disaster's impact.

The study concludes that the June 2019 heat wave in France was made at least five times more likely due to human-induced climate change. Observational data suggests a much higher increase in probability and a temperature rise of approximately 4ºC compared to a century ago, though climate models generally show lower trends and systematic biases in representing heat wave variability.