| NSF Org: |
OCE Division Of Ocean Sciences |
| Recipient: |
|
| Initial Amendment Date: | February 28, 2017 |
| Latest Amendment Date: | February 10, 2022 |
| Award Number: | 1658017 |
| Award Instrument: | Standard Grant |
| Program Manager: |
Joseph Carlin
OCE Division Of Ocean Sciences GEO Directorate for Geosciences |
| Start Date: | March 1, 2017 |
| End Date: | February 28, 2023 (Estimated) |
| Total Intended Award Amount: | $262,152.00 |
| Total Awarded Amount to Date: | $262,152.00 |
| Funds Obligated to Date: |
|
| History of Investigator: |
|
| Recipient Sponsored Research Office: |
1156 HIGH ST SANTA CRUZ CA US 95064-1077 (831)459-5278 |
| Sponsor Congressional District: |
|
| Primary Place of Performance: |
1156 High St Santa Cruz CA US 95064-1077 |
| Primary Place of
Performance Congressional District: |
|
| Unique Entity Identifier (UEI): |
|
| Parent UEI: |
|
| NSF Program(s): | Marine Geology and Geophysics |
| Primary Program Source: |
|
| Program Reference Code(s): |
|
| Program Element Code(s): |
|
| Award Agency Code: | 4900 |
| Fund Agency Code: | 4900 |
| Assistance Listing Number(s): | 47.050 |
ABSTRACT
This projects provides a case study of a past climate event, called the Eocene Thermal Maximum-2 to constrain natural recovery rates of climate and ocean chemistry following massive carbon input into Earth's surface reservoirs. The study will allow new insight into past climate and ocean acidification processes that were hitherto unexplored, hence promoting the progress of science and advancing the field of climatology. Such insight is essential to providing the public, scientific leaders, and policy makers with a better understanding of the consequences of unabated CO2 emissions for global climate, ocean carbonate chemistry, and marine ecosystems. Moreover, the project integrates research and educational activities by introducing this information directly into secondary school and college curricula and popular journals. The project fosters education for graduate and undergraduate students from ethnically diverse populations, while conducting cutting-edge research at the same time. The outcome of this study will advancethe understanding of the Earth system and hence improve forecasts of future climate change, which is beneficial to society.
Specifically, proxy records will be generated and used (d13C, d18O, %CaCO3, B/Ca, d11B) in combination with numerical modeling to determine natural recovery times for carbon cycle processes, temperature, and surface ocean acidification. The study will (1) provide fundamental insight into negative climate-carbon cycle feedbacks, (2) address important gaps in data coverage and understanding of Eocene hyperthermals, and (3) constrain critical parameter values needed for future climate-carbon cycle simulations.
PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH
Note:
When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external
site maintained by the publisher. Some full text articles may not yet be available without a
charge during the embargo (administrative interval).
Some links on this page may take you to non-federal websites. Their policies may differ from
this site.
PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
Project Outcomes Report
Intellectual Merit: The overall climate sensitivity to greenhouse forcing varies from model to model thus contributing to uncertainty in projections of future warming. One strategy for testing models is to assess their skill at replicating past greenhouse gas climates, in particular, periods of extreme warming, or hyperthermals. This study was designed to provide additional observational constraints on one of these hyperthermals, Eocene Thermal Maximum 2, specifically the changes in ocean/atmosphere carbon chemistry (e.g. pH, pCO2) and SST. A related objective was to constrain the rate of recovery from the peak greenhouse conditions and the role of feedbacks using C cycle models constrained by the constraints on carbon chemistry. Applying several proxies of seawater temperatures and carbonate chemistry including carbon isotopes, the B/Ca and B isotope composition of planktonic foraminifera, we constrain the rise in surface ocean temperature to +2.5-3.0 degrees C and a drop in pH to -0.10 to -0.15, the latter consistent with less than a doubling of pCO2. This suggests a climate sensitivity on the higher end of the spectrum for climate models (i.e., 4 to 5°C per doubling). In addition, there is good agreement in the rate of recovery in our observations and models further verifying the role of rock weathering as the primary negative feedback on the C cycle.
Broader Impacts: A primary societal implication of this work is that the current ranges of estimates for global warming based on climate model ensembles, that is 3 to 4°C with each doubling of atmospheric CO2, is consistent with observations of past warming events (within error). Moreover, the time for CO2 levels to recover following a major reduction of C emissions will be on the scale of tens of thousands of years via natural processes. Accelerating recovery rates will likely require human intervention (i.e., carbon dioxide removal).
Last Modified: 06/26/2023
Modified by: James C Zachos
Please report errors in award information by writing to: awardsearch@nsf.gov.
