Neil Pederson, Lamont-Doherty Earth Observatory (image) The Earth Institute at Columbia University Share Print E-Mail Caption Annual tree rings vary in relation to moisture and temperature, and can be read like a book. Study co-leader Neil Pederson of Lamont-Doherty Earth Observatory takes a cross section from a dead tree that may be well over 1,000 years old. Credit Kevin Krajick/Earth Institute, Columbia University Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.