page_title: Subboreal
section_title: Climatic evolution
hierarchical_section_title: Subboreal / Climatic evolution
context_page_description: The Subboreal is a climatic period, immediately before the present one, of the Holocene. It lasted from 3710 to 450 BCE.
context_section_description: The climate was generally dryer and slightly cooler (by about 0.1 °C) than in the preceding Atlantic but still warmer than today. The temperatures were 0.7 °C higher than during the following Subatlantic. Consequently, in Scandinavia the lower limit of glaciers was 100 to 200 m higher than during the Subatlantic. On the whole, the oscillating temperatures slightly receded in the course of the Subboreal by about 0.3 °C.
  In the Aegean, the beginning of the Subboreal was marked by a pronounced drought, centered around 5600 years BP. Of far greater importance as the coming to an end of the African Humid Period, reflected in the lakes of subtropical Africa (like Lake Chad) experiencing a rapid fall in their water levels. During the interval 6200 to 5000 years BP, drier conditions were in southern Mesopotamia, causing great demographic changes and probably instigating the end of Uruk.
  In Germany, a drastic climatic cooling can be observed around 5000 varve years BP in the maars of the Eifel. In the preceding interval lasting from 8200 till 5000 varve years (Holocene Climatic Optimum), the July temperatures were on average still 1 °C higher. At the same time, the January temperatures were rising and the yearly precipitation increased.
  In Northern Africa and in the Near East, the interval from 4700 to 4100 years BP had renewed and lasting dry conditions, as is indicated by lake level minima. Between 4500 and 4100 years BP, monsoonal precipitations weakened, a possible cause for the upheavals that led to the end of the Old Kingdom of Egypt.
  The Levant shows a similar climatic evolution. The dry conditions prevailing in Mesopotamia around 4200 years BP probably resulted in the downfall of the Akkadian Empire.
caption: Temperature variations during the Holocene
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