The BBVA Foundation Frontiers of Knowledge Award in the Climate Change category goes, in this fifteenth edition, to James C. Zachos and Ellen Thomas for their seminal contributions to the identification of a major natural event in the fossil record that provides a compelling analog for anthropogenic climate change.
This event, known as the PaleoEocene Thermal Maximum (or PETM), took place about 56 million years ago. Zachos and Thomas convincingly demonstrated that the PETM was characterized by 5-6ºC of warming and coincided with the release of massive quantities of CO2 and/or methane into Earth’s atmosphere, resulting in major extinction of deep-sea organisms and ocean acidification.
The PETM demonstrates the implications of a major perturbation of the global carbon cycle; one similar in magnitude to what is happening today. Zachos and Thomas’s analyses of marine and terrestrial records, made available through the painstaking efforts of international drilling programs, help bound Earth’s surface temperature sensitivity to increases in greenhouse gases; reveal the multi-millenary time scale over which natural processes remove carbon from the atmosphere; and contextualize present-day changes with respect to the geological past.