Climate Through Human History

Reconstructing Past Climates - Historical and Archaeological Data

Historical documents contain a wealth of information about past climates. Observations of weather and climatic conditions can be found in farmers' logs, travellers' diaries, newspaper accounts, and other written records. When properly evaluated, historical data can yield both qualitative and quantitative information about past climate.

These sources are less precise, but are more abundant and can extend several centuries in the past.

The example on the left demonstrates how historical grape harvest dates were used to reconstruct summer temperatures (April - September) in Paris from 1370 - 1879. [From Bradley, 1990; based on data Le Roy Ladurie and Baulant, 1980.]

Historical documents must be interpreted with care - understand background of diarist and observers (not used to the particular climate of the region).

Archaeological data - examine relationship between climatic changes and fluctuations in settlement and cultivation limits. Care must be taken not to apply a simple "cause and effect" approach (climate change could be only a background influence).