Climate

Climate change is intensifying extreme weather events and placing increasing pressure on global water resources, particularly in regions with high climatic variability such as Mexico. However, long-term changes in precipitation patterns and their implications for water resource vulnerability remain insufficiently characterized. This study analyzes historical precipitation trends from 1950 to 2018 and evaluates their implications for water resource vulnerability in the Lerma Santiago River System, one of Mexico’s most critical hydrological systems. A longitudinal analysis of nearly seven decades of precipitation data was conducted. Data quality and homogeneity were ensured using the RHtestV4s tool, and climate extremes and trends were assessed with the RClimDex package following ETCCDI guidelines. The findings indicate a significant decline in annual precipitation, with reductions of approximately 15% in downstream areas. Consecutive dry days increased by nearly 20%, while consecutive wet days decreased by about 10%. Although rainfall intensity has increased, events are concentrated over fewer days, amplifying water-scarcity risks. These climatic pressures are further compounded by dam construction, which restricts water availability. The results highlight the high vulnerability of the Lerma Santiago River System to combined climatic and anthropogenic stresses, underscoring the urgent need for integrated, multi-scale water and climate management strategies to enhance regional resilience.

Since early 2023, severe to exceptional drought has developed in southern coastal Australia, with dam levels falling as stream flows plummet. The wet season, April to September, reflects the most equatorward position of the mid-latitude westerly wind regime that brings rain-bearing systems to southern coastal Australia. Climatologically, an upper-level tropospheric split-jet is present in the Australia–New Zealand region. This is evident in the subtropical jet (STJ) location when the 1965 to 1995 u-component of the 250 hPa wind anomaly, relative to 1991 to 2020, is located above northern tropical Australia, and the weaker polar-front jet (PFJ) branch anomaly spans the mid-latitudes south of Australia. Permutation testing revealed a statistically significant decrease in the 2016 to 2025 wet season mean precipitation across southern Australia. Compared with the 1965 to 1995 u-component wind anomaly at 250 hPa, the 2006 to 2015 decadal anomaly still shows the split jet with the STJ branch over northern tropical Australia and the PFJ in the mid-latitudes of the Australia–New Zealand region. However, there is a dramatic change in position and structure of the STJ branch of the split jet, between the 1965 to 2015 and the 2026 to 2025 anomalies. The split jet structure has shifted approximately 10° poleward, causing rain-producing systems to track south of the Australian continent. The reduced precipitation can generate more frequent and intense droughts, with greatly reduced stream flows and dam levels. Historically, the low precipitation warm season follows from October to March when heatwaves, combined with pre-existing dry conditions, often create catastrophic bushfire conditions.

Sub-Saharan Africa faces intersecting challenges of water scarcity, climate-induced migration, and gender inequality, all of which have profound implications for health. These overlapping stressors, compounded by fragile socioeconomic conditions, contribute to heightened vulnerability, particularly among women, whose mobility is often restricted by gender norms, increasing their exposure to health risks. Despite the growing recognition of these challenges, the interconnected impacts on physical and psychosocial health remain underexplored. Understanding these overlapping issues supports integrated interventions and aligns with SDGs 3, 5, 6, and 13. The study aims to inform inclusive, context-specific policy responses that address the compounded health vulnerabilities of marginalized populations in Sub-Saharan Africa through climate-resilient and gender-responsive strategies. This study employed a mixed-methods approach combining a narrative review with key informant interviews to examine these linkages. Findings were thematically analyzed using systems thinking and a nexus approach to identify key patterns. It found that water stress, migration, gender inequality, and health outcomes are deeply interconnected in the region, with women disproportionately bearing the impacts. Gender norms amplify risks, leading to adverse physical, nutritional, and psychosocial health outcomes. Addressing these challenges requires integrated, gender-transformative, and cross-sectoral interventions that strengthen resilience, equity, and sustainable development in the region. This study underscores the urgency of adopting nexus-oriented, gender-transformative, and integrated policy and health responses within climate adaptation and development planning.