Key Climate Intervals in the Earths Past

This chapter looks at the Earth's climate over geologic time and demonstrates when key long- and short-term changes took place. Cli-matologists have been able to reconstruct a representative climatic time line by tapping into natural storehouses of data, such as corals, ocean and lake sediments, ice cores, fossil pollen, tree rings, and other physical clues left behind from natural processes. These types of data, known as proxy data, are natural records of climate variability. Through the analysis of proxy records, scientists can extend their understanding of past climate backward in geologic time. This chapter first looks at the Earth's most ancient climates (2 million to 4.6 billion years ago), then progresses to the Pleistocene climates (10,000 years to 2 million years ago), and finally looks at the Holocene/recent climates. It also addresses what climatologists have identified as the key uncertainties.

0 0

Post a comment