CLIMATE CHANGES OF THE LAST 2 MILLENNIA INFERRED FROM BOREHOLE TEMPERATURES - RESULTS FROM THE CZECH-REPUBLIC .2.

Borehole temperature logs are indicators of the temperature variations associated with the past climate change. Temperature-depth records fr om 98 holes drilled on the territory of the Czech Republic were invert ed to assess the ground surface temperature history. For most borehole s the climatic episodes over the two past millennia were identified, i ncluding warmer period around 400 A.D., followed by colder times betwe en 700-1000 A.D., the Little Climatic Optimum with its culmination aro und 1250 +/- 50 A.D., and the Little Ice Age with a temperature minimu m at 1650 +/- 30 A.D. Since the beginning of the 19th century a genera l warming has dominated the climate pattern interrupted by several sho rt-term oscillations, The characteristic times of the minimum (min) an d maximum (max) alternating extremes are: max 1730 +/- 20, min 1780 +/ - 10, max 1820 +/- 10, min 1880 +/- 10, max 1935 +/- 7, min 1943 +/- 5 , max 1976 +/- 3 A.D. The results are in good agreement with the long- term meteorological observations and proxy climatic records. As to the recent general warming trend (last about 30 yr), there exists a certa in geographical pattern of regions where the rate of warming was parti cularly intense or where it was relatively weaker possibly indicating a certain impact of human activities, The highest amount of warming of 2.6-2.8 K were obtained for the industrial regions of the Praha, nort hern Bohemia and Ostrava coal basins, while the lowest warming of 0.07 -0.6 K corresponds to the southwestern and southern slopes of the Bohe mian Massif, areas are generally forested.