On August 25, a violent landslide raced down a forested hillside in Ketchikan, Alaska, killing one person and injuring three. The natural disaster followed a period of unusually heavy rain known as an atmospheric river. Scientists said that intensifying rainfall, driven by climate change, could increase the risk of landslides in the area of Southeast Alaska that includes Ketchikan. “There’s no single factor that seems to underline each of these events apart from a lot of moisture,” said Josh Roering, professor of earth sciences at University of Oregon College of Arts and Sciences.