Past records of ocean acidification - the Palaeogene hyperthermals
Lead Research Organisation:
University of Bristol
Department Name: Earth Sciences
Abstract
Since the discovery of fire and the development of agriculture, humans have been releasing carbon dioxide (CO2) to the Earth's atmosphere. We have known about the effect that burning of fossil fuels and deforestation has on the amount of CO2 in the atmosphere as well as its influence on global temperatures for many years now. However, the CO2 we put in the atmosphere does not all just stay there / because CO2 reacts with water, about a third of current fossil fuel emissions is removed by the ocean. This effect would be really helpful for us in preventing more extreme global warming from taking place, except ... in past few years scientists have realized that because CO2 dissolved in seawater creates a weak acid, we are causing the pH of the ocean to steadily decrease in a process known as 'ocean acidification'. There are currently about 380 molecules of CO2 in the atmosphere for every million of all gases combined ('parts per million' or ppm). Atmospheric CO2 is predicted to steadily increase in the coming decades, reaching 450-550 ppm by the year 2050 / a concentration that our Planet has not experienced in at least the past 3 million years. As atmospheric CO2 increases, so does the rate at which it will dissolve in seawater, forcing the pH of the surface ocean lower and lower. It is likely that ocean pH will reach values seen only rarely since the time of the Dinosaurs. Most organisms alive in the ocean today have never experienced such a large change in all their evolutionary history. Is this important? From laboratory experiments it seems that ocean acidification will affect marine organisms, particularly those that make shells and skeletons out of calcium carbonate, because calcium carbonate minerals become less stable as waters become more acidic and will eventually dissolve. If we fail to control CO2 emissions to keep ocean pH change within the limits calcifying organisms can cope with in the future, we may see dissolution of their shells, slower growth, failure to reproduce, dwarfism, or reduced activity, with impacts further the ecosystem. Unrestricted industrial activities may even push these organisms over an ecological precipice and cause extinctions. So what is going to happen in the future? In the geological past, organisms normally had thousands to millions of years to adapt and evolve in response to global environmental change. Although the global environmental change we are causing now is many hundreds of times faster, it would still take laboratory experiments conducted over decades to tell us whether marine organisms will be able to adapt to ocean acidification. By the time we know the answer, it may be too late! Luckily, there is an alternative path; one that lies hidden in rocks. The geological record, stored in the mud at the bottom of the ocean is packed with millions of microfossils that record how much change organisms can tolerate and how much is too much. We will take samples of ancient sediments that have been drilled from the ocean floor, analyse these samples using a range of state-of-the-art techniques involving detailed laboratory analyses, and apply complex computer models to help make complete sense of the numbers. This will tell us how the pH of the ocean changed in the past. By linking this information with observations of ecosystem changes and species extinctions will provide vital clues to what changes in marine ecosystems we might expect in the future if we do not make much greater efforts to curtail our greenhouse gas emissions now.
Publications
Foster LC
(2013)
Surviving rapid climate change in the deep sea during the Paleogene hyperthermals.
in Proceedings of the National Academy of Sciences of the United States of America
Hönisch B
(2012)
The geological record of ocean acidification.
in Science (New York, N.Y.)
Turley C
(2010)
The societal challenge of ocean acidification.
in Marine pollution bulletin
Description | Predicting the impact of ongoing anthropogenic CO2 emissions on calcifying marine organisms is complex, due to the synergy between direct changes (acidification) and indirect changes through climate change (e.g., warming, changes in ocean circulation and deoxygenation). Laboratory experiments, particularly on longer-lived organisms, tend to be too short to reveal the potential of organisms to acclimatise, adapt or evolve, and usually do not incorporate multiple stressors. We studied two examples of rapid carbon release in the geological record, Eocene Thermal Maximum 2 (ETM-2 ~53.2 Ma) and the Paleocene Eocene Thermal Maximum (PETM ~55.53 Ma), the best analogs over the last 65 Ma for future ocean acidification related to high atmospheric CO2 levels. We use benthic foraminifers, which suffered severe extinction during the PETM, as a model group. Using Synchrotron Radiation X-ray Tomographic Microscopy (SRXTM), we reconstruct the calcification response of survivor species and find, contrary to expectations, that calcification significantly increased during the PETM. In contrast, there was no significant response to the smaller ETM-2, which was associated with a minor change in diversity only. These observations suggest that there is a response-threshold for extinction and calcification-response, while highlighting the utility of the geological record in helping constrain the sensitivity of biotic response to environmental change. |
Exploitation Route | We have contributed and continue to do so to the MCCIP partnership to inform end users of our science about the results. We have contributed to the IPCC report WGII to inform policy makers about the unexpected outcomes of our research. The PI was lead author of the ocean chapter (AR5 WGII Chapter 6) which included a historical view on climate change impacts on marine ecosystems. |
Sectors | Environment |
Description | The information has been included in the IPCC WGII AR5 Chapter 6 thereby providing important constraints on the impact of climate change on past ecosystems for policy makers. The importance of rate of change has been highlighted up to the Summery for Policy makers. The information is also included on a UK scale in the MCCIP report 2014 |
First Year Of Impact | 2013 |
Sector | Environment,Government, Democracy and Justice,Other |
Impact Types | Societal Policy & public services |
Description | IPCC |
Geographic Reach | Multiple continents/international |
Policy Influence Type | Citation in other policy documents |
Description | Marine climate change impact partnership |
Geographic Reach | National |
Policy Influence Type | Citation in other policy documents |
Description | Bristol Alumni funding |
Amount | £80,000 (GBP) |
Organisation | University of Bristol |
Department | Campaigns and Alumni Relations Office (CARO) |
Sector | Academic/University |
Country | United Kingdom |
Start | 01/2011 |
End | 04/2014 |
Description | Leverhulme Grant |
Amount | £162,000 (GBP) |
Organisation | The Leverhulme Trust |
Sector | Charity/Non Profit |
Country | United Kingdom |
Start | 01/2012 |
End | 02/2015 |
Description | Leverhulme visiting Professorship Ellen Thomas |
Amount | £39,000 (GBP) |
Organisation | The Leverhulme Trust |
Sector | Charity/Non Profit |
Country | United Kingdom |
Start | 01/2013 |
End | 06/2013 |
Description | UK OA RP |
Amount | £65,000 (GBP) |
Funding ID | UK Ocean acidification Reserach Program |
Organisation | Natural Environment Research Council |
Sector | Public |
Country | United Kingdom |
Start | 09/2012 |
End | 03/2015 |
Title | EBSD on foraminifers |
Description | Assessment of quality of preservation of fossil carbonate for isotope analysis using Electron Backscatter diffraction |
Type Of Material | Data analysis technique |
Provided To Others? | No |
Impact | A paper is currently under review which would make the method accessible. |
Title | calcification data |
Description | Synchrotron based calcification data for benthic foraminifers for the PETM and ETM2 |
Type Of Material | Database/Collection of data |
Year Produced | 2013 |
Provided To Others? | Yes |
Impact | publication of data in PNAS Inclusion of finding in IPCC report |
URL | http://www.pnas.org/content/110/23/9273.abstract |
Title | d11B analysis with the NERC ionprobe facility |
Description | d11B analysis with the NERC ionprobe facility Our grant resulted in a large investment of time by the ion probe team to improve the analytical technique, move the measurements to a new instrument and improve the quality of the data. |
Type Of Material | Data analysis technique |
Provided To Others? | No |
Impact | A paper with the method and the results is currently under review |
Description | New collaboration with Baerbel Hoenisch and NSF workshop organisation |
Organisation | Columbia University |
Department | Lamont Doherty Earth Observatory |
Country | United States |
Sector | Academic/University |
PI Contribution | New collaboration with Baerbel Hoenisch and NSF workshop organisation |
Start Year | 2010 |
Description | link to dPETM |
Organisation | University of Leeds |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | We have provided data to assess the ETM2, a post ocean acidification event which augments modelling efforts at Leeds |
Collaborator Contribution | The link to the none Bristol partners in the dPETM grant (also NERC funded) resulted in additional insights from climate models into the nature of our findings. These influence the interpretation and hence usefulness of this past Ocean acidification event for policy makers |
Impact | A paper is currently under review in Paleoceanography |
Start Year | 2010 |
Description | BBC "Points West" on Ocean acidification 2010 |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | Regional |
Primary Audience | Public/other audiences |
Results and Impact | BBC "Points West" on Ocean acidification 2010, TV interview Increased awareness of the general public about the impact of ocean acidification on marine ecosystems |
Year(s) Of Engagement Activity | 2010 |
Description | Interview for BBC world on Ocean acidification 2010 |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | Interview for BBC world on Ocean acidification 2010 It is hard to assess the impact of a radio interview but there is clear evidence that the awareness of the impacts of Ocean acidification have risen due to a number of communicators of which I consider myself to be one. |
Year(s) Of Engagement Activity | 2010 |
Description | Paleo-ocean acidification and carbon cycle perturbation events |
Form Of Engagement Activity | A magazine, newsletter or online publication |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Other academic audiences (collaborators, peers etc.) |
Results and Impact | Hönisch, B., Schmidt, D.N., Barker, S. and Zachos, J. 2011. Paleo-ocean acidification and carbon cycle perturbation events. Pages News, 19(1): 35. increased awareness of this new concern of environmental impacts of CO2 |
Year(s) Of Engagement Activity | 2011 |
Description | School Visit (Grammar School Salisbury) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Regional |
Primary Audience | Schools |
Results and Impact | I gave a presentation on Ocean acidification to the largest cohort of AS and A level Geology pupils in the country with a q and A session at the end. In addition to informing the pupils I also briefed the teachers with information. questions from the students, raising curiosity, novel research disseminated. |
Year(s) Of Engagement Activity | 2013 |
Description | University of Michigan Smith Lecture, Ann Arbor |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Undergraduate students |
Results and Impact | University of Michigan Smith Lecture, Ann Arbor, to undergraduates, graduates and other academics Stimulation of discussion amongst both the undergradute and graduate students. |
Year(s) Of Engagement Activity | 2010 |