4th millennium BC

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 4th millennium BC spanned the years 4000 BC to 3001 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 growth relaxed after the burst that came about from the Neolithic Revolution. World population was largely stable in this time at roughly 50 million, growing at an average of 0.027% per year.^[1]

^ Jean-Noël Biraben (1979). "Essai sur l'évolution du nombre des hommes". Population. 34 (1): 13–25. doi:10.2307/1531855. JSTOR 1531855. S2CID 143406315., estimates 40 million at 5000 BC and 100 million at 1600 BC, for an average growth rate of 0.027% p.a. over the Chalcolithic to Middle Bronze Age.

[1] Jean-Noël Biraben (1979). "Essai sur l'évolution du nombre des hommes". Population. 34 (1): 13–25. doi:10.2307/1531855. JSTOR 1531855. S2CID 143406315., estimates 40 million at 5000 BC and 100 million at 1600 BC, for an average growth rate of 0.027% p.a. over the Chalcolithic to Middle Bronze Age.

[1]

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