Dendrochronological Paleoclimate Reconstruction for Monsoon Asia

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With an objective of reconstructing paleoclimate over the past 500 years diagonally across Monsoon Asia, a series of field search for and subsequent increment core sampling from old trees was conducted at a total of 32 sites in Kamchatka Peninsular, Japan, Laos and the Nepal Himalayas, resulting in a total of some 1800 increment cores from some 900 individual trees. The longest core was obtained from Fokienia hodginsii of apparent age of over 1000 years located in Northern Laos.A series of analysis of ring-width variation in response to local climate for each sampling site and subsequent conversion of ring-width index using site specific transfer functions resulted in paleoclimate reconstruction of past 300 yrs for Eastern Nepal, 285 yrs for Western Nepal, 420 yrs for Central Kamchatka, 210 yrs for Southern Kamchatka and 240 yrs for Island of Shikoku, Japan. The 700-yrs reconstruction for Northern Laos is yet to come due to difficulty from limited number of samples and more or less obscure rings. Comparison of these local reconstructions revealed a regionally integrated trend of global warming appearing definitely and as early as two centuries ago in Kamchatka to show later and less definitely southward, ending up virtually no existent in the Himalayas. This regional trend of the past global warming is consistent with projected future trend of definite warming in higher latitudes with increasingly less warring in lower latitudes.