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The document argues that the 2022 Brisbane and 2022/23 Kimberley floods were made more likely and impactful by human-caused climate change, specifically through increased ocean temperatures, more frequent multi-year La Niña events, and higher atmospheric moisture. It concludes that while the frequency of some weather systems may decrease, the intensity of rainfall and flooding is expected to increase, potentially leading to prohibitive costs for protection and insurance in flood-prone zones.

The study finds that anthropogenic climate change approximately tripled the probability of the April 2026 heatwave in northwestern India and Pakistan, making it about 1°C hotter than it would have been in a preindustrial climate. Analysis indicates that extreme heat is occurring earlier in the season, with the likelihood and intensity of April events increasing more rapidly than those in May. This trend extends the period of dangerous heat exposure for hundreds of millions of people, compounding risks to health, agriculture, and the economy. The report also highlights systemic vulnerabilities, noting that heatwaves are not officially declared disasters in India and Pakistan, which limits access to relief funding.

The report finds that anthropogenic climate change has significantly increased the probability of dangerous humid heat during the 2026 FIFA World Cup compared to 1994. Using Wet Bulb Globe Temperature (WBGT) as a metric, the analysis indicates that more games are expected to exceed the 26C and 28C thresholds recommended by FIFPRO for cooling breaks and postponement, respectively. While air-conditioned stadiums may mitigate risks for players, spectators at outdoor events remain vulnerable. The study concludes that without substantial adaptation and rapid mitigation of fossil fuel use, hosting summer tournaments in the northern hemisphere will become increasingly hazardous.

The report analyzes a record-shattering heatwave in the southwestern United States and northern Mexico in March 2026, finding that such an event would have been virtually impossible without anthropogenic climate change. Using a combination of observation-based data and climate models, the study estimates that the intensity of 1-in-100-year March heat events has increased by 2.6°C and their likelihood has increased by a factor of approximately 800. The document highlights the extreme vulnerability of non-acclimatized populations and the risk of accelerated snowmelt in the Sierra Nevada and Colorado mountains.

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.

The document identifies a shift from outright climate denialism to 'strategic skepticism,' where influential entities—including fossil fuel companies and right-wing populist movements—undermine climate action by questioning the economic efficiency and causes of climate change. It highlights that policymakers are primary targets of this disinformation, which is disseminated through social media, corporate sustainability reports, and interpersonal networks. The report argues that this environment erodes public trust in climate science and creates a cycle of political inaction. To combat this, the authors recommend standardized carbon reporting legislation, legal action against 'greenwashing,' the creation of multi-stakeholder coalitions, and the enhancement of scientific and media literacy for both the public and officials.

The document explains attribution studies—which use climate models to determine if and how much human-induced climate change affected a specific event—and provides guidance on reporting various extreme phenomena. It details how global warming increases the probability and intensity of heatwaves and heavy precipitation globally, while the effects on droughts, wildfires, and tropical cyclones vary by region or specific metric. It emphasizes that while climate change influences the risk and intensity of these events, human factors like land use and water management also contribute to whether an event becomes a disaster.

The Climate Central Temperature Attribution System (CC-TAS) Version 1.0 operationalizes a multi-method framework to attribute temperature events to anthropogenic climate change. It utilizes two empirical methods (median-scaling and quantile-scaling) and a model-based method using CMIP6 simulations. To improve upon previous frameworks, CC-TAS incorporates high-resolution CFS reanalysis temperatures, ERA5 reanalysis for scale factors, and skew-normal parameterized distributions. The system introduces the 'occurrence ratio' (OR) as a primary metric to assess both warm and cold events, which is then converted into a conservative categorical 'Climate Shift Index' (CSI) for public mapping, primarily focusing on the contiguous United States.

The report concludes that the June 2021 Pacific Northwest heatwave was virtually impossible without human-caused climate change, estimating it as a 1-in-1000 year event in the current climate. The analysis indicates the event was approximately 2°C hotter than it would have been in a pre-industrial climate and would have been at least 150 times rarer without anthropogenic warming. Future projections suggest that in a world with 2°C of global warming, such an event would occur every 5 to 10 years and be another degree hotter. Meteorological drivers included an 'omega-block' high-pressure system and dry antecedent soil conditions, while natural variability modes like ENSO and PDO played little to no role.

The report concludes that the prolonged regional heat in Siberia from January to June 2020 was effectively impossible without human influence, with a best estimate probability ratio of 99,000 compared to a 1900 climate. Such events would have been at least 2°C cooler without anthropogenic influence. For the specific record of 38°C at Verkhoyansk, the study found a confident anthropogenic shift in intensity of 1.5°C, although the probability ratio for this specific station event is of lower confidence. By 2050, the regional heat is expected to be further intensified, with a synthesis change in intensity of 4.85°C compared to 1900.

The analysis finds that anthropogenic climate change has significantly increased the probability of extreme fire weather and heatwaves in southeastern Australia, while having no attributable trend in dry extremes. Specifically, the probability of a Fire Weather Index as high as in 2019/20 has increased by more than a factor of four since 1900. Heatwaves of similar intensity are now approximately 10 times more likely than they were around 1900. While climate change increased the overall risk, the specific severity of the 2019 event was further amplified by natural variability, specifically the Indian Ocean Dipole and the Southern Annular Mode.

The study finds that the extreme two-day rainfall during Tropical Storm Imelda in September 2019 was made more likely and more intense by anthropogenic climate change. Observational data suggests the probability of such an event has increased by a factor of 2.6 since 1900, while climate model synthesis indicates a probability increase of 1.5 to 3.1 times and an intensity increase of 9% to 21%. The report also notes that rapid urban expansion and loss of impervious cover in Southeast Texas have exacerbated flooding risks for approximately 6.6 million people in the impacted counties.

The analysis concludes that human-induced climate change has made the June 2019 heatwave in France more likely and more intense. Observational data suggests that a heatwave of this intensity is occurring at least 10 times more frequently today than a century ago, with temperatures approximately 4C higher. While climate models qualitatively agree on the strong human influence, they show smaller trends and fewer severe heatwaves than observations, simulating a probability increase of between a factor of 2 and 20. The study emphasizes that early-season heatwaves in June have more severe health and organizational impacts than mid-summer events.

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.

In early July 2018, southwestern Japan experienced extreme rainfall, with some interior stations recording more than twice the usual amount for the wettest day of the year, leading to local return times exceeding 200 years. Observational data from 94 stations show a higher prevalence of positive trends in extreme rainfall probability than negative trends, suggesting a systematic influence beyond natural variability. While a single high-resolution model (EC-Earth T799) qualitatively reproduces these positive trends from 1850 to 2098, the authors state that a lack of sufficient climate models and manpower prevents a robust quantitative attribution statement. The analysis concludes that climate change likely increased the probability of such extreme rains, though the exact magnitude remains undetermined.

An international team of scientists used a multi-method attribution approach to determine that anthropogenic climate change increased the likelihood of the 2015-2017 Western Cape drought by a factor of 3.3. The drought, characterized by three consecutive years of below-average rainfall, led to a severe water crisis in Cape Town, nearly resulting in 'day zero'. The study finds that drought risk in this region scales linearly with warming, suggesting that further temperature increases will continue to raise the probability of such extreme events.

The report concludes that Olifants River flows will likely decline substantially due to a combination of projected precipitation decreases and increased evaporation driven by rising temperatures. Using IPCC data and the South African Climate Change Reference Atlas, the author finds that warming is virtually certain, while annual precipitation is very likely to decrease by 5% to 25%. Drawing on analogs from the American Southwest, the analysis argues that even modest precipitation increases would be overwhelmed by temperature-induced evaporation. The document warns that these flow reductions will exacerbate existing water quality issues, such as pollutant concentrations and harmful algal blooms, and advises against the construction of new coal-fired power plants in the region.

The study concludes that human-induced climate change had no significant influence on the occurrence of Storms Eleanor and Friederike. While observational data from the past 40 years show a decrease in near-surface wind speeds, climate models suggest a marginal increase in the probability of extreme hourly winds (0-20%) by the middle of the century due to greenhouse gases. The observed decline in storminess is attributed to factors other than climate change, such as increased surface roughness, aerosols, and decadal variability.

The analysis concludes that river flows in the Mokolo and Crocodile (West) catchments are very likely to decline due to a combination of projected precipitation decreases and increased evaporation driven by rising temperatures. Using the American Southwest as a semi-arid analog, the author argues that temperature-induced flow declines will occur even if modest precipitation increases happen. The report warns that these systems are already over-allocated and that further warming, potentially reaching 5°C under high-emissions scenarios, will exacerbate water shortages and increase the frequency of 'flash droughts'.

The document outlines five key strategies for communicating climate science: managing audience expectations about the scientific process, framing uncertainty as risk, focusing on established facts, emphasizing scientific consensus, and using visual storytelling.