A short film about an expedition to Tibet's Guliya Glacier, where scientists drilled a Stone Age ice core going back 600,000 years. Plus a report on what the ice core reveals.
Meltwater from the glaciers supplies water to 800 million people, so that loss would mean serious consequences for water management, food security, energy production.
The report shows the warming trend that's transforming the Arctic region is persisting. The Arctic shows no sign of returning to reliably frozen region of recent past decades, say scientists.
The intense wildfires in southern California are triggering air quality alerts. What do health experts know about how inhaling smoke affects human health?
A 245-million-year-old fossil horseshoe crab, recently discovered in Idaho, has been named Vaderlimulus after Star Wars' Darth Vader. It's easy to see why.