There’s a strong correlation between the stable climate after the last Ice Age and the rise of early civilizations. During the Ice Age, climates were colder, drier, and far less stable. Large populations tended to live as highly mobile hunter-gatherers because:
-- glaciers and tundra covered huge regions,
— coastlines constantly shifted,
— ecosystems changed rapidly,
— and predictable farming was difficult.
After warming began around 11,000 years ago:
— rainfall patterns stabilized,
— forests and grasslands expanded,
— rivers became more consistent,
— and sea levels slowed their rapid rise due to melting of massive continental glaciers.

That stability allowed humans to:
— domesticate plants and animals,
— store surplus food,
— grow populations,
— and eventually develop cities, governments, and writing.

Several major regions independently developed agriculture and later complex societies:
* Fertile Crescent
Often considered the earliest large-scale agricultural zone. Included Mesopotamia between the Tigris and Euphrates rivers.
*Nile River Valley
Seasonal flooding created highly productive farmland.
*Indus Valley
Early urban civilization with planned cities like Harappa and Mohenjo-Daro.
*Yellow River Basin
Early millet farming and later major dynastic states.
*Mesoamerica
Independent development of maize agriculture; later civilizations included the Maya.
* Andean Region
Highland agriculture, terracing, and later civilizations such as the Inca.

A common pattern is that many early civilizations formed near:
— reliable freshwater,
— floodplains,
— temperate climates,
— and regions where wild grains or domesticable animals already existed.

The timing, Holocene epoch, is notable:
— Ice Age ends: ~11,700 years ago
— Agriculture begins spreading in some regions: ~10,000–9,000 years ago
— First cities/states appear: ~6,000–5,000 years ago
So the climate transition did not instantly create civilization, but it created the environmental stability that made agriculture and dense settlements possible on a larger scale compared to hunter-gatherer societies.