THE CLIMAP PROJECT (Climate: Long range Investigation, Mapping, and Prediction), run by the World Data Center for Paleoclimatology, first published its oceanic map in 1981. Although nominally meant to map ocean conditions, the project gave insight into global warming, due to the fact that oceanic conditions in a region distant from the ice sheets were largely dependent on greenhouse gases. Therefore, a model of the conditions thousands of years ago compared to current conditions could provide evidence for human-caused global warming.
Although CLIMAP is frequently cited as a useful resource for mapping oceanic conditions during the last glacial maximum, several of its claims are controversial and, perhaps, misestimates. Unfortunately, collecting sediment core samples from the Pacific Ocean is quite expensive; therefore, re-collecting the data or obtaining more samples is difficult and unlikely.
The World Data Center for Paleoclimatology is based in Boulder, Colorado, and operated by the National Climatic Data Center (NCDC) in Ashe-ville, North Carolina, along with the National Data Center for Meteorology. The NCDC is part of the National Environmental Satellite, Data, and Information Service (NESDIS), a part of the National Oceanic and Atmospheric Administration within the U.S. Department of Commerce. Its mission is to: "provide access and stewardship to the nation’s resource of global climate and weather related data and information, and assess and monitor climate variation and change," and is self-proclaimed the "world’s largest archive of climate data."
Within the NCDC, there are six branches for data: Land-Based; Marine; Paleoclimatology; Satellite; Upper Air; and Weather/Climate, Events, Information & Assessments. The Paleoclimatology branch manages the World Data Center for Climatology and the Applied Research Center for Climatology; it also deals with CLIMAP. Paleoclimatology is the study of climates before the current era, when accurate, high technology instrumentation was not available. Therefore, paleoclimatologists reconstruct models of climates from such data sources as corals, ice cores, ocean and lake sediments, and tree rings; these data sources are called natural proxy sources.
CLIMAP was based on research during the 1970s (the International Decade of Ocean Exploration) and 1980s, focusing on mapping the Earth’s climate during the period of the last glacial maximum (approximately 18,000 years ago). Researchers for the CLIMAP Project collected numerous sediment core samples, and generated detailed maps of the climate 18,000 years ago, with information such as glacial patterns and vegetation zones. The core samples were from anywhere between 24,000 and 14,000 years ago; during this period, the climate was assumed to be relatively constant and stable.
After thorough analysis, the CLIMAP scientists predicted that the sea surface temperatures (SST) in the tropics were only three or fewer degrees C cooler than they are today; this estimate is considered by most Earth scientists to be inaccurate. Many scientists instead support the theory that the tropical SSTs have since dropped closer to 5-6 degrees C. How this discrepancy arose is unknown.
