Measles risk crossed the threshold unseen, and floods and hunting are also running ahead of the models
Three models published in Nature journals reevaluate global risk assumptions: a US transmission model shows school-level measles risk crossing epidemic thresholds, global river flood intervals vary sharply across climate zones, and hunting footprints expand into remote tropical regions.
Science··Morning
US school-level measles risk crossed the epidemic threshold unseen
A nationwide transmission model tracking vaccination records across 45 US states and Washington, DC, indicates that school-level effective reproduction numbers crossed the epidemic threshold in 2022−2023. The study, which includes data from more than 50,000 schools across 3,000 counties, shows that average susceptibility doubled to approximately 10 percent after the pandemic. The mismatch between administrative boundaries and school catchments leaves well-vaccinated counties open to spillover from neighboring districts. These localized shifts remain invisible in broader county-level aggregates, complicating the country's measles elimination status.[1]
Rivers spill at different intervals than global flood models assume
Global flood inundation models traditionally assume that rivers reach their bankfull discharge capacity once every two years. However, high-resolution machine learning analysis along the global river network finds that while the two-year estimate approximates overall magnitude, actual recurrence intervals depend heavily on the climate zone. Bankfull conditions return with a median period of 1.5 years in tropical basins and 1.8 years in temperate areas, but extend to 2.8 years in cold regions and 4.3 years in arid zones.[2]
Hunting's footprint now covers the whole tropical belt
Increased human accessibility between 2000 and 2015 has expanded hunting pressure across the entire pantropical zone, reaching previously undisturbed areas like the Amazon basin. A machine-learning model trained on 2,463 ecological sites generated standardized global maps indicating high hunting probabilities in the Brazilian Atlantic Forest, parts of West Africa, and the Indomalayan realm, including China and western India. Remote interiors in Borneo, Papua New Guinea, and Central Africa persist as the remaining refuges against this continuous deepening of localized hunting pressure.[3]
