Scientists warn that “flying rivers” — invisible streams of moisture that carry rain from the Atlantic Ocean westward across the Amazon — are weakening as deforestation and climate change advance. That’s because the trees that are being lost are crucial to essentially passing the moisture westward. A new analysis finds southern Peru and northern Bolivia are especially vulnerable to increasing droughts. The disruption could destabilize forests, farming and hydropower, with ripple effects across South America and beyond. Experts say halting deforestation and restoring forests are key to preserving these vital systems.