Temperature Notes

Neolithic Times    4070 BC
  • mean average 12-13° C, around 2.5° C higher than today (5500 - 3500 BC). Climate C 20th.

  • (Qualifier: temperatures in the first part of the C 20th were about 1° C higher than in the middle of the century.)

    Roman Times:  warmer than now, vines grown for wine in SE England.

    After the 1st century AD there is evidence of a progressive rise in sea level.
    AD 400 to 1000. The important invasions of western Europe by the Huns and the Goths may have been generated by deteriorating climatic conditions in central Asia. Radiocarbon dating and studies of the ancient Chinese literature have disclosed that, when the glaciers of central Asia were large, the meltwaters fed springs, rivers, and lakes on the edge of the desert, and human communities flourished. When there was a warm phase, the water supply failed and the deserts encroached.
    Approximately AD 1000-1250 the worldwide warm-up that culminated in the 10th century and has been called the early Medieval Warm Period or the "Little Climatic Optimum".
    This interval, extending roughly from AD 1250 to 1500, corresponds to the Paria Emergence in the eustatic record and has
    been called one of the "little ice ages" by certain authors.
    Little Ice Age (1500-1850). Throughout most of what is commonly called the Little Ice Age (1500-1850) the mean solar activity was quite low, but positive fluctuations occurred around 1540-90 and 1770-1800.
    The year 1850 started a brief warming trend that persisted for 100 years. It also approximates a critical turning point in climatic,
    sea level, glacial, and sedimentologic records.
    The Earth now is on a long-term cooling trend of the glacial-interglacial cycles and is likely to continue so for several thousand
    years, but there are numerous modulating influences, meteorologic, geologic, and man-made.

    Geochronology: The Interpretation and Dating of the Geologic Record.

    Copyright (c) 1996 Encyclopaedia Britannica, Inc.(extracts only). a, Inc.(extracts only).