Progress in global lake drilling holds potential for global change research

During the past decade, numerous international investigations of past global change have focused on particular time intervals, or “Time Streams,” suggested by the Past Global Changes (PAGES) Project of the International Geosphere-Biosphere Programme (IGBP). Time Stream 1 encompasses the last 2000 years, and Time Stream 2 encompasses at least the last 250,000 years. Geographically many of these studies have been grouped into north-south transects of continental global change records known as the Pole-Equator-Pole (PEP) transects [Bradley et al., 1995]. These continental transects have been complemented by the study of marine records included in the International Marine Global Change Study (IMAGES) transects and high-latitude ice core records such as those from the U.S. Greenland Ice Sheet Project 2 (GISP2) and the European Greenland Ice-core Project (GRIP).