New approaches to constructing age models: OxCal4

When looking at past changes in the climate and their impact on the environment, timing is all-important. This is not so much because we want to know exactly when something happened but because we want to know how fast and in what order the changes occurred. For this reason, very well dated records, such as ice-cores, play a major role in our understanding of past climate. For most environmental records we need to make use of less precise dating methods, such as radiocarbon or Uranium series, sometimes in conjunction with relative dating information from varves or deposition-rate models. In order to improve overall dating precision, assumptions are also sometimes made about the synchronous nature of climate change—assumptions that can result in circular reasoning when we come to interpret the results.