Historical Paleoclimatology

A better understanding of how present climate can change and increased awareness of the full range of climate variability are crucial to improve forecasting of weather, climate and extreme events. However without records of wind, temperature, rainfall, humidity and other weather characteristics, accurate descriptions of past climate are difficult. Scientists working in the field of paleoclimatology have turned to natural records of climate, such as the sediments at lake bottoms, the widths of tree rings, and the chemicals stored in glacial ice or coral reefs to piece together a story of Earth's climate before the era of instrumental measurements of climate and weather conditions. A subfield of paleoclimatology, historic paleoclimatology, reconstructs past climate conditions from historical references and documentary evidence, such as church records, harvest dates, or harbor ice-free dates. This approach was used by the study's international team of nine researchers while working in Spain's General Archive of the Indies (Archivo General de Indias). For the first time, scientists turned to the sailing records from Manila galleons to learn about past climate.

"This idea started with the knowledge that these voyages had taken place, and that there are very few observations of climate before 1800," said Henry Diaz, a lead researcher for the project who works at NOAA's Physical Sciences Division. "We were thrilled to find that these records could give us a unique look at climate of the Pacific Basin during the few hundred years prior to large-scale weather observing."