Last season, 60 Minutes witnessed the migration of monarch butterflies. Scientists are now using tiny, solar-powered radio tags to track individual butterflies and learn more about their migration.

"What we're seeing is things like extreme heat waves, levels of temperature change in Antarctica we've never seen before and didn't expect to see. We're seeing the ice retreating at a rate we'd never ...

Scientists are flocking to Iceland to investigate an increasingly crucial question: Will melting glaciers accelerate and intensify earthquakes and volcanic eruptions? William Brangham reports. PBS ...