Sunday, March 23, 2014

Study finds Medieval Warm Period in Tibet was warmer than the year 2000 & the Sun controls climate

A paper published in 2013 reconstructs temperatures of the Tibetan Plateau over the past 2,500 years and finds "temperatures during the Medieval Warm Period were slightly higher than the modern period in this region. Further, our temperature reconstructions...can be well correlated with solar irradiance changes, suggesting a possible link between solar forcing and natural climate variability, at least on the northern Tibetan Plateau."

Solar activity reconstruction on top graph correlates with temperature reconstruction on bottom graph. Note the year 2000 at at the left side of this graph. 
Multiple reconstructions show the Medieval Warm Period was warmer than the end of the 20th century.


HE YuXin1, LIU WeiGuo2*, ZHAO Cheng1, WANG Zheng2, WANG HuanYe2, LIU Yi3,
QIN XianYan3, HU QiHou3, AN ZhiSheng2 & LIU ZhongHui1*

Considerable efforts have been made to extend temperature records beyond the instrumental period through proxy reconstructions, in order to further understand the mechanisms of past climate variability. Yet, the global coverage of existing temperature records is still limited, especially for some key regions like the Tibetan Plateau and for earlier times including the Medieval Warm Period (MWP). Here we present decadally-resolved, alkenone-based, temperature records from two lakes on the northern Tibetan Plateau. Characterized by marked temperature variability, our records provide evidence that temperatures during the MWP were slightly higher than the modern period in this region. Further, our temperature reconstructions, within age uncertainty, can be well correlated with solar irradiance changes, suggesting a possible link between solar forcing and natural climate variability, at least on the northern Tibetan Plateau.

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