1. Cornell Tree Ring Laboratory; Cornell University; Ithaca NY 14853 USA
2. NASA/GISS, 2880 Broadway, New York, NY 10025; USA and Lamont-Doherty Earth Observatory; Palisades NY USA
3. University of Heidelberg; Heidelberg Germany
4. Indiana University − Southeast; New Albany IN USA
5. W.M. Keck Carbon Cycle AMS Laboratory; University of California at Irvine; Irvine CA USA