Figure 1

The stalagmite δ18O record of the East Asian monsoon from Sanbao Cave in China3 (A) and a synthetic reconstruction of millennial variability over the same time period24 (B) compared with the composite, detrended (C) and original and time series of δ18O from three stalagmites from Huagapo Cave in Peru (D). December insolation at 10°S35 (E) is also shown. For the detrended Huagapo record (C) a composite of the three samples was constructed and a 9th order polynomial fit was subtracted from it to remove orbital scale variability (and see Fig. S2).