A WORLD WITH ICE

50 million years of cooling

Over the last 50 million years, Earth has cooled down from a warm, ice-free world to its current state with polar ice caps. Ice only started to accumulate in Antarctica around 30 million years ago, while the Arctic ice sheet did not start forming until roughly 5 million years ago

Cooling of Earth after the PETM

• X-axis: Millions of years
• Y-axis: Temperature
• Grey area 1: Antarctic ice sheet
• Grey area 2: N. hemisphere ice sheet
• Dashed line: Current average global temperature
• Arrow 1: India-Asia collision
• Arrow 2: Circumpolar current
• Arrow 3: Isthmus of Panama

The warm Earth 50 million years ago

Polar ice caps over the last 2 million years