4000 B.C.

Millennia:	5th millennium BC 4th millennium BC 3rd millennium BC
Centuries:	40th century BC 39th century BC 38th century BC 37th century BC 36th century BC 35th century BC 34th century BC 33rd century BC 32nd century BC 31st century BC

The Neolithic This box:
↑ Mesolithic
Fertile Crescent Heavy Neolithic Shepherd Neolithic Trihedral Neolithic Pre-Pottery (A, B) Qaraoun culture Tahunian culture Yarmukian Culture Halaf culture Halaf-Ubaid Transitional period Ubaid culture Byblos Jericho Tell Aswad Çatalhöyük Jarmo Europe Arzachena culture Boian culture Butmir culture Cardium Pottery culture Cernavodă culture Coțofeni culture Cucuteni-Trypillian culture Dudeşti culture Gorneşti culture Gumelniţa–Karanovo culture Hamangia culture Khirokitia Linear Pottery culture Malta Temples Ozieri culture Petreşti culture Shulaveri-Shomu culture Sesklo culture Tisza culture Tiszapolgár culture Usatovo culture Varna culture Vinča culture Vučedol culture Neolithic Transylvania Neolithic Southeastern Europe China Peiligang culture Pengtoushan culture Beixin culture Cishan culture Dadiwan culture Houli culture Xinglongwa culture Xinle culture Zhaobaogou culture Hemudu culture Daxi culture Majiabang culture Yangshao culture Hongshan culture Dawenkou culture Songze culture Liangzhu culture Majiayao culture Qujialing culture Longshan culture Baodun culture Shijiahe culture Yueshi culture Tibet South Asia Mehrgarh Bhirrana Neolithic Philippines Jade culture
farming, animal husbandry pottery, metallurgy, wheel circular ditches, henges, megaliths Neolithic religion
↓ Chalcolithic

Holocene Epoch This box:
↑
Holocene
Preboreal (10.3–9 ka) Boreal (9–7.5 ka) Atlantic (7.5–5 ka) Subboreal (5–2.5 ka) Subatlantic (2.5 ka–present)

The 4th millennium BC spans the years 4000 through 3000 BC. Some of the major changes in human culture during this time included the beginning of the Bronze Age and the invention of writing, which played a major role in starting recorded history.

The city states of Sumer and the kingdom of Egypt were established and grew to prominence. Agriculture spread widely across Eurasia. World population in the course of the millennium doubled, approximately from 7 to 14 million people.

farming, animal husbandry
pottery, metallurgy, wheel
circular ditches, henges, megaliths
Neolithic religion

Based on studies by glaciologist Lonnie Thompson, professor at Ohio State University and researcher with the Byrd Polar Research Center, a number of indicators shows there was a global change in climate 5,200 years ago, probably due to a drop in solar energy output as hypothesized by Ohio State University.

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Wikipedia