Spotlight on the trailblazers hunting for climate solutions

NPR’s Climate Week coverage includes a story about an app taking on food waste and a report on a group of health-care workers who are reducing their industry’s carbon footprint. This week’s In Conversation examines how the AR-15 became the most popular rifle in the U.S. — and what that rise tells us about where we go from here. Vox explains why that $7 latte is $7.