Instrumental climate data only extend back to the mid-19th century, at best, which means that the anthropogenic climate change signals we are chasing are in most cases longer than the available climate records. A wealth of climate history can be extracted from geologic archives such as corals, deep-sea sediments, cave stalagmites, lake deposits, tree rings, and ice cores. Recent advances in research techniques mean that paleoclimate data have approached the resolution and fidelity of instrumental climate data. This is especially true in many remote regions of the world, where long, high-quality instrumental climate records are often lacking. Using meticulously calibrated climate “proxies”, paleoclimatologists construct centuries- to millennia-long timeseries of climatic histories. They use such records to quantify the range of natural climate variability, investigate the mechanisms of past global climate change events, and gauge the accuracy of computer simulations of past climate changes made under a variety of different climate forcings. The ultimate goal of paleoclimate research is to help identify the strengths and weaknesses of global climate models – models that are charged with projecting the future impacts of anthropogenic climate change. Such projections (and their uncertainties) are arguably the most important input for cost-benefit analyses designed to critically assess the consequences of climate change adaptation and/or mitigation strategies.
Our group’s mission is to uncover the mechanisms of global climate change, both natural and anthropogenic, in order to inform projections of future climate change. We focus primarily on the generation of new high-resolution records of past tropical Pacific climate variability from corals and cave stalagmites, with an emphasis on the last decades to centuries. Through the thoughtful combination of climate models and data, we seek to characterize natural climate variability in this region and identify climate trends that are associated with anthropogenic climate change.
Thanks to NSF grants AGS-0645291, OCE-0752091, and AGS-1203785, and NOAA grant NA11OAR4310165. Field support provided by The Nature Conservancy, Norwegian Cruise Lines, the WAITT foundation, and the Palmyra Atoll Research Consortium.
Learn more about my research on my web-page.
Dr. Kim Cobb, Georgia Tech