Final answer:
Scientists use proxies like ice cores, tree rings, and fossils to detect climate change prior to written records. These methods reveal past climate patterns and help construct a detailed history of Earth's climate and atmospheric composition.
Step-by-step explanation:
To detect climate change prior to written records, scientists use various indirect measures or proxies such as ice cores, tree rings, glacier size, pollen counts, and ocean sediments.
These proxies help build a picture of Earth's past climate, indicating temperature and precipitation patterns before written history began. Notably, analyzing tree rings provides an annual record of climate variations, as each ring corresponds to one year of growth, which can be influenced by climate conditions.
Similarly, ice cores can contain trapped air bubbles that preserve a timeline of atmospheric composition, including greenhouse gas concentrations from hundreds of thousands of years ago.
Additionally, the geological record includes other types of evidence like fossils and sediment cores. For instance, fossilized remains of foraminifera (microscopic marine organisms) can tell us about past sea temperatures depending on the orientation of their shells.
Such interdisciplinary efforts, combining history and paleo-science, allow for a more comprehensive understanding of the effects and causes of historical climate change events.