Weather records, in some form or another, go back to early human civilizations. There are, however, other longer-term records captured in nature. Today, scientists read these proxy weather sources in an effort to better understand the causes of previous climate changes and make forecasts about our future climate.
Tree ring sections provide excellent climatic histories of specific regions, usually going back several hundred years. Generally, the rings are thicker in warm, wet growing seasons and thin during periods of drought. They can also display evidence of wildfires.
Glacial ice is an excellent environmental record keeper. Formed in seasonal layers, each band conveys information about the climatic conditions that existed when the ice formed. The air bubbles trapped in the ice are particularly valuable, as they provide direct samples of past atmospheric compositions. Some ice cores provide climate information dating back more than 100,000 years.
The rock record is another window that allows scientists to look into prehistoric climates. Sedimentary rocks are valuable sources of information as they often capture the environmental character of a region from millions of years ago. Their composition, as well as the fossils found within them, can indicate the rise and fall of ancient sea levels.
The diverse research of Paleoclimatology has given us a detailed view of how Earth’s climate has changed throughout its long history. We have also come to understand that climate and human activities have a significant relationship. Our activities influence climate and, in turn, climate effects how we live.