DECODING THE MARINE GEOLOGICAL RECORD

The co-variation of CO₂ release with environmental changes presents a uniquely annoying challenge to the interpretation of the marine geological record, as the same processes that imprint evidence for changes in ocean acidification (decreased carbonate saturation) act to distort or even erode the record of other proxy information (e.g. carbon isotopes). Bioturbating organisms additionally impart a filter on the primary environmental information that we would like to extract, changing the phase and reducing the amplitude of the original driving signal. Here, using examples of abrupt CO₂ release and warming events (‘hyperthermals’) of the late Paleocene and early Eocene, I highlight the development and application of Earth system models to overcoming these complicating factors and ‘inverting’ deep sea marine records to extract the primary signal.