Glaciers are frozen records of the planet's climate history. They take thousands of years to form, shape entire valleys and support ecosystems found nowhere else.
From snow to ice
It starts with snow that never melts in summer. Layer on layer, pressure squeezes out the air and turns crystals into compact ice. Once the mass is tens of metres thick, it begins to flow under its own weight.
A river that walks
A glacier moves between centimetres and several metres a day. That motion opens crevasses, polishes rock and carries sediment; the U-shaped valleys of Norway or Patagonia are literally its signature.
Why they are crucial
- They hold around 70% of the planet's fresh water.
- Their ice cores preserve atmospheric bubbles thousands of years old: the best climate archive we have.
- They feed rivers that millions depend on across Asia and South America.
- They reflect solar radiation and help regulate global temperature.
Seeing them while they are here
Iceland, Greenland and Patagonia let you walk on ice with a certified guide and crampons. It is the clearest way to grasp the retreat: your guide will show you where the front stood ten years ago.
