Event type:
Seminar, Virtual event
Organised by:
Pal(a)eo PERCS
Event status:
EVENT CLOSED
About Pal(a)eo PERCS
Pal(a)eo PERCS (Paleo EaRly Career Seminars) is a weekly seminar series that promotes and features work by early career researchers who are working in the broad field of “Pal(a)eo” sciences (e.g., -ntology, -ecology, -oceanography, -climate). PERCS is intended as a venue to share research, strengthen the global community, and facilitate collaboration between the Paleo sciences. All paleo- researchers and fans are enthusiastically welcome.
About this seminar
As the concentration of atmospheric carbon dioxide (pCO2) continues to rise along with the increasing demands from our growing population, we need to understand the precise relationship between pCO2 and climate (aka climate sensitivity) to brace for the future.
Over the past one million years, pCO2 has shown a striking relationship with temperature, as recorded in air bubbles trapped in ice cores. However, beyond the one-million-year ice core record, we must rely on proxies to reconstruct pCO2, i.e. physically preserved materials which reflect an environmental parameter. Developing and calibrating proxies remains a challenge, with different proxies suggesting different values throughout time. To provide geologic context for climate sensitivity, we need to better constrain proxy uncertainty.
Here, we apply this proxy over the mid-Miocene Climatic Optimum (16.9 to 14.7 Ma) for several reasons: 1. It may be an analogue for the near future, 2. It seems to behave differently than other climates in time, and 3. It has highly varied pCO2 estimates during this time. We use a refreshed approach to reconstruct pCO2 from the stable carbon isotopic fractionation that occurs during photosynthesis.
Possibly providing a more universal pCO2 proxy (both in time and location) in the geologic record, we develop and test the potential of the organic geochemical compounds that are many by most phytoplankton: phytane, a degradation product of the vital pigment chlorophyll that can be found in all photoautotrophs e.g. plants and algae and cholestane, a degradation product of cholesterol found in all (and only) eukaryotes.
This refreshed approach, combined with global temperatures, is used to calculate climate sensitivity. We find that this period is not in fact exceptional and its climate sensitivity is firmly within the standard IPCC estimates, thus resolving the enigma of the warm mid-Miocene.
The seminar will begin at 1.30pm UTC.
Speaker
Dr Caitlyn Witkowski, University of Bristol, UK
Registration
An access link will be emailed to all those subscribed to the mailing list prior to the seminar.
Venue
All seminars will be hosted via Zoom.
Accessibility
All Pal(a)eo PERCS seminars are closed captioned. If you require any other particular accessibility accommodations to be put in place, please do get in touch with the committee, who will be happy to accommodate those as best they can.
Contact
Please contact the Pal(a)eo PERCS steering committee via [email protected] with any enquiries.