Dendrochronology is the science of dating tree rings to determine past climatic conditions and environmental changes. By examining the patterns of growth in tree rings, scientists can infer information about past climate variations, such as temperature and precipitation levels. Dendrochronology is often used in combination with other dating methods, such as radiocarbon dating, to establish accurate chronologies for archaeological sites or historical events. This field of research helps scientists understand the long-term patterns of climate change and how ecosystems have responded to these changes over time.