Response of climate to solar forcing recorded in a 6000-year delta O-18 time-series of Chinese peat cellulose

Previous studies have shown that the oxygen isotope ratio (delta(18)O) of p lant cellulose can serve as a sensitive proxy indicator of past climate, bu t its application has mainly been restricted to tree-rings. Here we present a 6000-year high-resolution delta(18)O record of peat plant cellulose from northeastern China. The delta(18)O Variation is interpreted as reflecting changes in regional surface air temperature. The climate events inferred fr om the isotope data agree well with archaeological and historic evidence. T he record shows a striking correspondence of climate events to nearly all o f the apparent solar activity changes characterized by the atmospheric radi ocarbon in tree-rings over the past 6000 years. Spectral analysis of the de lta(18)O record reveals the periodicities of around 86, 93, 101, 110, 127, 132, 140, 155, 207, 245, 311, 590, 820 and 1046 years, which are similar to those detected in the solar excursions. We consider these observations as further evidence for a close relationship between solar activity and climat e variations on timescales of decades to centuries. Our results also have i mplications for distinguishing between natural and anthropogenic contributi ons to future climate change.