Paleoclimate: The History of the Earth System
The USGCRPbudget includes $27 million in FY 2001 for the study of the Earth’s amazingly complex climate and environmental history (see Table 9). This element of the USGCRP focuses on providing a quantitative understanding of how the environment has changed in the past and defining the envelope of na...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.388.6555 http://www.gcrio.org/ocp2001/ocp2001_sec7.pdf |
| Summary: | The USGCRPbudget includes $27 million in FY 2001 for the study of the Earth’s amazingly complex climate and environmental history (see Table 9). This element of the USGCRP focuses on providing a quantitative understanding of how the environment has changed in the past and defining the envelope of natural environmental variability within which the effects of human activities on the planet’s biosphere, geosphere, and atmosphere can be assessed. Paleoenvironmental records are derived from a wide variety of natural archives— such as: lake and ocean sediments, tree rings, wind-blown deposits, coral, and ice cores—as well as historical documents. Chemical, isotopic, and ecological analyses of these records have demonstrated that the natural climate system has varied locally and globally over a far greater range than can be inferred from relatively short-term instrumental records. In most locations, instrumental records might provide 100 years of climate data, whereas an ice core might provide an annual climate record of 10,000 to 30,000 years (more than 400,000 years in Antarctica). Understanding the natural environmental changes of our planet on long timescales (years to millennia) provides the context for understanding today’s climate dynamics and elucidating the effects of natural versus anthropogenic influences. Reconstructing past climate records offers an enhanced understanding of mechanisms that control the Earth’s climate system and, together with insight from numerical modeling exercises, provides a foundation for anticipating how the planet might respond to future environmental perturbations. |
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