Western disturbances (WD) and Indian Summer Monsoon (ISM) are two key atmospheric phenomena driving the complex hydroclimate over India, subsequently influencing the winter and monsoon season of the subcontinent. In recent decades, the WDs have been increasingly observed in the monsoon season, potentially enhancing their interaction with the Indian Summer Monsoon. This interaction is prone to high-impact precipitation extremes (such as the Uttarakhand flood 2013, Himachal Flood 2023) over Northern India and the Himalayan region, potentially impacting the water security and disaster preparedness of the region. Despite their importance, the role of climate change in modulating these WD–ISM precipitation extremes remain underexplored. To address this crucial gap, the study investigates the shift in WD occurrences during the monsoon season and their co-occurrence with extreme precipitation events for the period 1950-2024 over the Hindu Kush Himalayan region using multiple precipitation datasets, including ERA5, CPC, MSWEP and the WD track dataset (developed by Hunt et al. 2018). Additionally, a probabilistic climate attribution framework has been applied in this research using CMIP6 model simulations to compare the occurrence of such extremes in factual (recent) and counterfactual (pre-industrial) climate conditions. Preliminary findings indicate a significant increasing observed trend of ~0.054 events per year (p=0.002) in the occurrence of WD-associated monsoon extreme systems during 1950–2024, with a more pronounced rise in recent decades. Subsequently, a significant upward tendency (p

Extreme event attribution studies are becoming increasingly prominent, with nearly 1,000 analyses conducted to date and many more expected as operational attribution services are being launched. While the field is growing rapidly, this proliferation raises an important question: how can we ensure that each study meaningfully contributes to our understanding of climate change impacts, rather than merely adding to a growing volume of isolated results? Just as in broader climate science, it is essential to understand how different lines of evidence combine, to translate this surge of activity into robust, cumulative knowledge.This keynote examines what causal links climate scientists can legitimately make, how these links are established, and how uncertainty shapes—but does not preclude—robust conclusions. Drawing on more than a decade of experience from World Weather Attribution (WWA), it uses event attribution studies as a central example of scientific causal reasoning. Event attribution assesses whether and to what extent human-induced climate change hasaltered the likelihood or severity of specific extreme weather events. Such studies have become routine, with heatwaves dominating in Europe and globally and heavy rainfall studies concentrated in parts of Asia and North America, while major gaps remain in the rest of the world.Recent findings highlight that often, differences between datasets explain more variance than the precise definition of an event. This has implications for the added value of further quantitative attribution in well-studied regions and for identifying when new analyses are scientifically necessary, and in general for the meaningfulness of granular climate information.

The climate crisis is increasingly contributing to a mental health crisis. Policy and practice inadequately account for the mental health costs of climate change and the mental health benefits of climate action. The climate and mental health field is expanding rapidly but unevenly. Connecting Climate Minds (CCM), a global initiative, aimed to develop a guiding vision to ensure investment in and implementation of future research aligns with lived experience needs and appropriately informs policies. CCM convened 1184 contributors with diverse expertise across 126 countries, through 21 online and in-person dialogues. Their insights produced a Global Research and Action Agenda for climate change and mental health. This paper outlines the 53 research priorities structured into four high-level themes (impacts, risks and vulnerable groups; pathways and mechanisms; mental health benefits and risks of climate action; mental health interventions). It also outlines how to implement research and translate evidence to action.

In early 2026, an exceptional extreme weather events struck Southern Africa. Following heavy and persistent rains, rivers within the region exceeded their alert levels, causing large-scale flooding in South Africa, Mozambique, Zimbabwe and Eswatini. In January 2026, Mozambique’s National Institute of Meteorology (INAM) reported that several regions received record-breaking 24-hour rainfall, surpassing their annual averages. Notably, Gaza (Massangena station) recorded 271.9 mm on January 11, Maputo (Maputo Observatory) saw 213 mm on January 19, and Inhambane (Massinga station) reached 253 mm on January 10. The combination of very intense rainfall over a short period, together with high vulnerability and exposure, led to the worst flooding in Mozambique in 25 years. This led to severe socioeconomic losses, characterized by loss of life, casualties, and extensive damage to critical infrastructure in the region. At seasonal timescales, large parts of the study regions experienced record-breaking surface weather associated with the influence of La Nina setting up favourable circulation patterns for heavy rainfall. This study analyses the atmospheric and oceanic patterns linked to the event, as well as the influence of climate change, using reanalysis and gridded observational datasets. Using a probabilistic attribution approach, we found that the heavy rainfall was an exceptionally rare event in today’s climate, characterized by a high local return period. Furthermore, human-induced climate change and the weak La Niña increased the intensity and frequency of events of this magnitude. This study contributes to an improved process-understanding of extreme weather events in the region with implications for adaptation and disaster risk management.

In early 2016, Kenya experienced a whiplash between two opposing extreme events: extreme heat in March followed by heavy rainfall in April. In particular, the North-East region (Mandera, Wajir, Isiolo, Marsabit, and Samburu counties) endured an ‘ultra extreme’ 20-day heat event, defined using the Heat-Wave Magnitude Index daily (HWMId), followed closely by a 4-day heavy rainfall period. This type of compound event, which involves a succession of individual events, is termed a ‘temporally-compounding event’ and can be particularly devastating as the initial event ‘preconditions’ the human and physical environment, thereby exacerbating the impacts of the second event.There is a dearth of literature on compound events in East Africa, despite their increasingly common nature. Here we present an attribution methodology to disentangle the mechanisms driving temporally-compounding events to fill this gap. While attribution studies are still predominantly performed on individual extreme events, those which do consider compound events tend to focus on co-occurring multivariate events. The attribution of temporally-compounding events is, however, still in its infancy.There are an additional range of factors to consider when attributing the drivers of a succession of hazards when compared to an individual extreme event. We build upon existing proposed methodologies to navigate these complicating factors, such as deciding between univariate or multivariate thresholds for event definitions, and deciding the ‘reasonable’ time interval between the cessation of the first event and the instigation of the second.This research aims to contribute to the shared understanding of the interactions between the mechanisms driving compound events, specifically temporally-compounding events, within an East African context. This improved understanding can be used to inform locally-specific compound event definitions which can ultimately inform effective early-warning systems. By determining the relative contributions of anthropogenic climate change and natural variability on the 2016 Kenyan event, this research also hopes to lay the foundation for future attribution studies on compound events in the region.

From October 2020 to early 2023, Eastern Africa experienced five consecutive failed (SPEI -2.6) rainy seasons, resulting in the worst drought in 40 years. This led to harvest failures, livestock losses, water scarcity, and conflicts, leaving approximately 4.35 million people in need of humanitarian aid. To understand the role of human-induced climate change in the drought, we analysed rainfall trends and the combined effect of rainfall deficit with high temperatures in the Southern Horn of Africa covering parts of southern Ethiopia, southern Somalia, and eastern Kenya. We employed various climate models and observations to assess changes in 24-month rainfall (2021–2022), and seasonal rainfall; both the (March-April-May, MAM) ‘long rains’ and (October-November-December, OND) ‘short rains’ in 2022. We also contextualised the event in terms of vulnerability and exposure to understand how these elements influenced the magnitude of the impacts. Our analysis shows that anthropogenic influence on the combined effects of low rainfall and high evapotranspiration caused by higher temperatures made the drought exceptional, leading to major crop and pasture losses and water shortages. Our results also show a decline in rainfall during MAM and an upward trend during OND, which is attributable to climate change. Despite the wetting trend in OND season, the drought years concluded with successive La Niña conditions, typically linked with below-average rainfall in the region during that season. We do not find a trend in the 24-month precipitation. The assessment on vulnerability and exposure highlights the need for enhanced preparedness of government drought management systems and international aid infrastructure for future severe and prolonged droughts. The study's findings, combined with climate projections that indicate increased heavy precipitation in the region, underscore the pressing necessity for robust adaptation strategies that can address both wet and dry extremes. The impacts of climate change in Eastern Africa necessitate investments in adaptive measures and resilience building that can evolve with emerging climate signals.

While event attribution has made considerable progress in the last two decades, event impact attribution, which calculates the attributable share of impacts from extreme weather events, remains challenging. Impacts result from the interaction between the intensity of hazards, the exposure of affected areas and the vulnerability of individuals, infrastructures and the environment. Across different types of extreme weather events, impacts and world regions, a wide range of datasets and approaches need to be considered to tackle this complex and interdisciplinary field of research. Here, we aim to develop simple methods that can be deployed rapidly and globally to estimate attributable impacts in the aftermath of extreme weather events. We will present initial work on attributing direct economic impacts from tropical cyclones and on an updated global physical asset database used in this context. This initiative produces near-real-time results that can be communicated in a timely manner to a broad audience, raising awareness about the impacts of extreme weather and the role of climate change. It ultimately seeks to provide valuable information on losses and damages and levels of adaptation, which can be instrumental for policymaking, climate justice and preparing societies for future extremes.

Heat-related deaths occur throughout the summer months, peak during heatwaves, and are affected by temperature and exposed populations’ sensitivities to meteorological conditions. Previous studies found that climate change is increasing heat-related mortality worldwide. We build on existing epidemiological methods to shed light on the adverse effects of climate change on human health. We address limitations in existing methods and apply refined approaches to assess heat mortality attributable to human-induced climate change in Zürich, Switzerland, over 50 years (1969–2018) including a case study of summer 2018. Our methodological refinements affect how counterfactual climate scenarios are derived, and facilitate accounting for changing vulnerability, and assessing impacts during and outside heatwaves. We find nearly 1,700 heat-related deaths attributable to human-induced climate change between 1969 and 2018. Declining vulnerability to heat avoided at least 700 heat-related deaths. The approach described here could be applied elsewhere to quantify the effect of climate change on other health outcomes.

While the field of event impact attribution is still relatively nascent, diverse methodologies and datasets are starting to be used to put numbers on the share of additional impacts that occur due to climate change during extreme weather events. The growth of this body of evidence has implications for climate litigation as these studies can be starting points for legal cases centred around specific climate change impacts, such as heat-related mortality or economic costs of extreme weather. As we work towards operationalising a tracker that will provide timely estimates of losses and damages from extreme weather events globally, we aim to present results from our initial rapid studies conducted over the past year. We will reflect on the potential implications of the increasing availability of loss and damage information and the broader need for communication and awareness raising around these issues. We also plan to highlight prevailing methodological challenges and areas of research to be advanced in the near future that are relevant for legal efforts.

Researchers have examined how extreme weather experiences influence climate change attitudes, beliefs, and behaviors, with mixed results. However, limited research has explored how extreme weather experiences may affect climate-related perceptions and behaviors among climate activists. Given the significant role activism plays in climate action, as well as frequent dropout and burnout among activists, it is important to understand to what extent, how, and why extreme weather may influence individual climate activism. This study explores reported influences of extreme weather experiences on climate perceptions and activism through interviews with 33 Australian adults who directly experienced bushfires and previously engaged in climate activism. All participants felt more vulnerable to climate change after experiencing bushfires. Fifteen participants (45%) increased their activism; 13 (39%) maintained the same activism level; and 5 (15%) decreased their activism. Participants who increased their activism sought to share their bushfire stories with news media, policymakers, and through artistic projects. Climate activism helped several participants cope with bushfire-related trauma, whereas several other participants reduced their activism because their experiences undermined self-efficacy (perception that one can act on climate change). These findings show the divergent ways individuals may respond to extreme weather experiences and have implications for climate action mobilization strategies.

Capsule summary. Extreme temperatures in the UK (July 2022) and India/Pakistan (Spring 2022) are confidently attributed to climate change using an automated system. Similarly attributable extremes occurred frequently worldwide in 2022.

Event attribution methods are increasingly routinely used to assess the role of climate change in individual weather events. In order to draw robust conclusions about whether changes observed in the real world can be attributed to anthropogenic climate change, it is necessary to analyse trends in observations alongside those in climate models, where the factors driving changes in weather patterns are known. Here we present a quantitative statistical synthesis method, developed over 8 years of conducting rapid probabilistic event attribution studies, to combine quantitative attribution results from multi-model ensembles and other, qualitative, lines of evidence in a single framework to draw quantitative conclusions about the overarching role of human-induced climate change in individual weather events.

In the 2022 summer, western–central Europe and several other regions in the northern extratropics experienced substantial soil moisture deficits in the wake of precipitation shortages and elevated temperatures. Much of Europe has not witnessed a more severe soil drought since at least the mid-20th century, raising the question whether this is a manifestation of our warming climate. Here, we employ a well-established statistical approach to attribute the low 2022 summer soil moisture to human-induced climate change using observation-driven soil moisture estimates and climate models. We find that in western–central Europe, a June–August root zone soil moisture drought such as in 2022 is expected to occur once in 20 years in the present climate but would have occurred only about once per century during preindustrial times. The entire northern extratropics show an even stronger global warming imprint with a 20-fold soil drought probability increase or higher, but we note that the underlying uncertainty is large. Reasons are manifold but include the lack of direct soil moisture observations at the required spatiotemporal scales, the limitations of remotely sensed estimates, and the resulting need to simulate soil moisture with land surface models driven by meteorological data. Nevertheless, observation-based products indicate long-term declining summer soil moisture for both regions, and this tendency is likely fueled by regional warming, while no clear trends emerge for precipitation. Finally, our climate model analysis suggests that under 2 ∘C global warming, 2022-like soil drought conditions would become twice as likely for western–central Europe compared to today and would take place nearly every year across the northern extratropics.

Heavy rainfall in eastern Africa between late 2019 and mid 2020 caused devastating floods and landslides throughout the region. These rains drove the levels of Lake Victoria to a record-breaking maximum in the second half of May 2020. The combination of high lake levels, consequent shoreline flooding, and flooding of tributary rivers caused hundreds of casualties and damage to housing, agriculture, and infrastructure in the riparian countries of Uganda, Kenya, and Tanzania. Media and government reports linked the heavy precipitation and floods to anthropogenic climate change, but a formal scientific attribution study has not been carried out so far. In this study, we characterize the spatial extent and impacts of the floods in the Lake Victoria basin and then investigate to what extent human-induced climate change influenced the probability and magnitude of the record-breaking lake levels and associated flooding by applying a multi-model extreme event attribution methodology. Using remote-sensing-based flood mapping tools, we find that more than 29 000 people living within a 50 km radius of the lake shorelines were affected by floods between April and July 2020. Precipitation in the basin was the highest recorded in at least 3 decades, causing lake levels to rise by 1.21 m between late 2019 and mid 2020. The flood, defined as a 6-month rise in lake levels as extreme as that observed in the lead-up to May 2020, is estimated to be a 63-year event in the current climate. Based on observations and climate model simulations, the best estimate is that the event has become more likely by a factor of 1.8 in the current climate compared to a pre-industrial climate and that in the absence of anthropogenic climate change an event with the same return period would have led lake levels to rise by 7 cm less than observed. Nonetheless, uncertainties in the attribution statement are relatively large due to large natural variability and include the possibility of no observed attributable change in the probability of the event (probability ratio, 95 % confidence interval 0.8–15.8) or in the magnitude of lake level rise during an event with the same return period (magnitude change, 95 % confidence interval 0–14 cm). In addition to anthropogenic climate change, other possible drivers of the floods and their impacts include human land and water management, the exposure and vulnerability of settlements and economic activities located in flood-prone areas, and modes of climate variability that modulate seasonal precipitation. The attribution statement could be strengthened by using a larger number of climate model simulations, as well as by quantitatively accounting for non-meteorological drivers of the flood and potential unforced modes of climate variability. By disentangling the role of anthropogenic climate change and natural variability in the high-impact 2020 floods in the Lake Victoria basin, this paper contributes to a better understanding of changing hydrometeorological extremes in eastern Africa and the African Great Lakes region.

Since the UNFCCC Paris Agreement came into force after 2015 international climate policy rests on three pillars: mitigation, adaptation and loss and damage. However, while there are clear agreed-upon metrics to measure emissions, base mitigation goals against and hold countries and companies accountable to, the evidence base for the impacts of climate change to inform adaptation and loss and damage is very different. There are no agreed-upon metrics, nor are there guidelines or criteria to delineate the impacts of climate change from other drivers of losses and damages. This imbalance is reflected in the lack of ability to set and enforce goals. With a new body of scientific evidence introduced in the IPCC, we argue that this can change. Especially with an increasing number of climate litigation cases being recognised as a legitimate root to justice, and thus being given due consideration in courts, the imbalance in evidence could change and put adaptation and loss and damage on more equal footing with mitigation.

The science of event attribution is relatively nascent. While its body of knowledge is growing fast, numerous gaps remain, including on the appropriate statistical methods and the proper consideration of various degrees of vulnerabilities and exposure. We show that attributing climate change to internal displacement requires a focus on the interplay between climate and non-climate drivers of impacts via a feasibility study of the 2020 floods in Somalia. Using detailed internal displacement flow data, we describe the socio-spatial characteristics associated with the flooding event. We show that climate change has a limited role in revealing displacement impacts and magnitude following the extreme event.

Climate extremes are on the rise. Impacts of extreme climate and weather events on ecosystem services and ultimately human well-being can be partially attenuated by the organismic, structural, and functional diversity of the affected land surface. However, the ongoing transformation of terrestrial ecosystems through intensified exploitation and management may put this buffering capacity at risk. Here, we summarize the evidence that reductions in biodiversity can destabilize the functioning of ecosystems facing climate extremes. We then explore if impaired ecosystem functioning could, in turn, exacerbate climate extremes. We argue that only a comprehensive approach, incorporating both ecological and hydrometeorological perspectives, enables us to understand and predict the entire feedback system between altered biodiversity and climate extremes. This ambition, however, requires a reformulation of current research priorities to emphasize the bidirectional effects that link ecology and atmospheric processes.