Ice, in the simple physical sense, forms whenever liquid water cools below 0 °C (32 °F) at normal atmospheric pressure and solidifies into a crystalline solid called ice Ih.

What “ice” means here

  • In everyday language, ice is just frozen water, whether that is frost on the ground, cubes in a freezer, or glacier ice.
  • At Earth’s surface conditions, this frozen water most commonly takes the crystalline form called ice Ih, which is the stable structure below 0 °C at standard pressure.

When ice forms on Earth

  • Liquid water begins to freeze into ice at 0 °C under normal atmospheric pressure, so any time and place water cools below this temperature, ice can form (for example, winter lakes, snow, freezer ice).
  • Water vapour in the air can also deposit directly as ice (frost or snowflakes) when air is below 0 °C, bypassing the liquid phase.

How far back ice goes in Earth history

  • Geologically, ice on Earth has existed for hundreds of millions of years; there is evidence of major “icehouse” periods, including ancient glaciations over 600 million years ago, showing that large ice sheets and glaciers formed long before humans.
  • Over the last few million years, repeated ice ages have produced vast continental ice sheets and polar caps, so large-scale natural ice has been a recurring feature of Earth’s climate.

Humans and the history of making/using ice

  • Ancient civilizations were cutting and storing natural ice at least by around 1000 BC in China, using it to preserve food.
  • Egyptians and Indians were deliberately making ice on cold nights by placing shallow pots of water outside by around 500 BC, and Persians were storing ice in sophisticated desert icehouses (yakhchals) by about 400 BC.

Modern artificial ice

  • Large-scale artificial ice production began in the 19th century with mechanical refrigeration; by the late 1800s and early 1900s, plant‑made ice was overtaking naturally harvested ice in the commercial trade.
  • Today, ice is routinely produced in domestic freezers and industrial ice machines for food, medicine, and climate control, building on that 19th–20th century refrigeration revolution.

Information gathered from public forums or data available on the internet and portrayed here.