Many schools closed in the spring, during the first wave of the coronavirus pandemic. Many opened in the fall. Staff Writer Jennifer Couzin-Frankel joins host Sarah Crespi to talk about what was learned in spring about how coronavirus spreads in schools that might help keep children safe as cases surge once again. Also this week: What makes leaves fall off deciduous trees when they do—is it the short, cold nights? Or is the timing of so-called “leaf senescence” linked to when spring happens? Sarah talked to Constantin Zohner, a lead scientist at the Institute of Integrative Biology at ETH Zurich, about his tree leaf timing study. Sarah also spoke with commentary author Christy Rollinson, a forest ecologist at the Morton Arboretum, about how important these trees and the timing of their leaf drop is for climate change. In the books segment, host Kiki Sanford talks with Ruth DeFries about her book, What Would Nature Do? A Guide for Our Uncertain Times. This week’s episode was produced with help from Podigy. Listen to previous podcasts. About the Science Podcast Download a transcript (PDF).