Southern High Latitude Vegetation Response to Rapid Climate Change at the Cenozoic Greenhouse to Icehouse Transition

Lead Research Organisation: Northumbria University
Department Name: Fac of Engineering and Environment

Abstract

PROJECT SUMMARY As a result of continuous burning of fossil fuel, the global environment is facing a crisis stemming from rapidly rising concentrations of carbon dioxide and other greenhouse gases in our atmosphere. Assuming greenhouse gas emissions at or above current rates, carbon dioxide will reach nearly triple the pre-industrial concentrations by the end of this century. This is expected to raise global mean temperatures to a level not seen for more than 32 million years. According to the latest assessment of the Intergovernmental Panel on Climate Change, the high latitudes will experience the largest temperature increases, resulting in a rapid melting of polar ice-sheets and global sea level rise. For a further understanding of potential changes that our world may undergo in the future, it is vital to study environmental changes during past warm periods and across major climatic thresholds. The proposed research project will reconstruct past vegetation of Antarctica and southern Australasia during the Eocene (ca 55-34 million years ago). The Eocene is a geological time period of exceptional warmth, with atmospheric CO2 concentrations exceeding triple the pre-industrial levels. The project will reconstruct past vegetation by analysing pollen in sediments deposited during Eocene times. Vegetation provides detailed information on a number of important environmental parameters, such as annual temperature and precipitation, length of growing season, minimum and maximum temperatures, and soils. Of particular interest for this study are very short-lived time intervals during the early and late Eocene, during which carbon dioxide concentration and temperatures changed rapidly. For a full understanding of their climate forcings and mechanisms, the analysed sediments must have a high time resolution and unambiguous dating control, in order to relate them to respective past climate events. The marine cores 1171 and 1171, taken offshore Tasmania as part of the International Ocean Deep Drilling Programme Leg 189, as well as Eocene rock outcrops at Cape Foulwind in New Zealand, have been chosen for the proposed study, as they provide an unprecedented opportunity to produce high resolution pollen records for Antarctica and adjacent sub-polar regions. The data will be interpreted in a global context and related to Arctic palaeoenvironmental reconstructions by integrating them into the global GIS database TEVIS (Tertiary Environment and Vegetation Information System). The TEVIS dataset will be compared with a number of simulations using the cutting edge Hadley Centre climate model (used within the climate assessment reports of the Intergovernmental Panel of Climate Change IPCC). By combining regional high-resolution pollen analyses with global data-model comparison, this proposed study will foster a deeper understanding of how the terrestrial environments and polar ice sheets responded, and might respond in the future, to rapid changes in temperatures and atmospheric CO2 concentration. By indicating weakness and strength, the data-model comparison will also contribute to the improvement of climate models that we rely upon for simulating future climate change.

Publications

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Salzmann, U. (2012) Early to Middle Miocene vegetation and climate at the Wilkes Land margin in The 56th Annual Meeting of the Palaeontological Association, Dublin

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Salzmann, U. (2012) Early to middle Miocene vegetation and climate at the Wilkes Land margin, East Antarctica in The Micropalaeontological Society Annual General Meeting 2012, Keyworth, Nottingham, 11-13 November 2012

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Sangiorgi, F. (2012) Middle Miocene environmental and climatic evolution at the Wilkes Land margin, East Antarctica in American Geophysical Union Fall Meeting

 
Description We analysed pollen and spores in marine sediments taken by the Integrated Ocean Drilling Program Expedition 318 to
the Wilkes Land margin (East Antarctica) and established a unique record of climate cooling and Antarctic vegetation change from a subtropical, highly diverse Eocene rainforest to an Oligocene cold temperate forest and an impoverished Miocene sub-Antarctic shrubland. The pollen record suggests that temperatures were higher than in the Ross Sea region (i.e. Andrill, Cape Roberts) and the Wilkes Land margins were possibly one of the last refugia for temperate forest taxa on Antarctica during the Late Oligocene.

We also developed a new approach in identifying reworking in Eocene to Miocene pollen records from offshore Antarctica, using red fluorescence.Our study provides an essential new tool required to accurately reconstruct Cenozoic terrestrial climate change on Antarctica using fossil pollen and spores.

We additionally developed a new global vegetation and terrestrial climate reconstructions of the Priabonian (late Eocene; 38-33.9 Ma) and Rupelian (early Oligocene; 33.9-28.45 Ma) to further investigate the terrestrial response to climate change at the Eocene - Oligocene transition (EOT; ca. 34-33.5 Ma). Estimated temperatures using a Nearest Living Relative approach did not indicate global cooling and reconstructed biomes, using a new statistical approach, did not show an equatorward zonal shift at the EOT. Our terrestrial based climate reconstructions are in stark contrast to many marine based climate estimates and raise new questions on the nature and extent of terrestrial global climate change at the EOT.
Exploitation Route Our terrestrial based climate reconstructions are in stark contrast to many marine based climate estimates and raise new questions on the nature and extent of terrestrial global climate change at the EOT. Our new apporach using fluorescence microscopy provides an essential new tool required to accurately reconstruct Cenozoic terrestrial climate change on Antarctica using fossil pollen and spores.
Sectors Education,Environment,Other

 
Description Outcomes of this project have been used for research informed teaching projects at university and during public lectures. Publications of key findings of this project are still under review.
First Year Of Impact 2014
Sector Education
Impact Types Cultural

 
Description Contribution to IPPC 2013 report
Geographic Reach Multiple continents/international 
Policy Influence Type Gave evidence to a government review
Impact The Working Group I contribution provides a comprehensive assessment of the physical science basis of climate change including summary for policy makers
URL http://www.ipcc.ch/index.htm
 
Description NERC Palaeoclimate Forum NCAS
Geographic Reach National 
Policy Influence Type Participation in advisory committee
Impact To identify the requirements and priorities for maintenance and development of the UK National Capability in global paleoclimate modelling over the next 3-5 years, in the context of the wider NERC strategy for Earth System Modelling
 
Description Earth and Environment, University Leeds 
Organisation University of Leeds
Department School of Earth and Environment
Country United Kingdom 
Sector Academic/University 
PI Contribution Collaboration with Prof. Alan Haywood, University Leeds
Collaborator Contribution Climate Modelling
Impact see publication list
Start Year 2010
 
Description GNS New Zealand 
Organisation GNS Science
Country New Zealand 
Sector Public 
PI Contribution Collaboration with Dr. Ian Raine, GNS New Zealand
Start Year 2011
 
Description University Utrecht, Dept. Earth Sciences, Faculty of Geosciences 
Organisation Utrecht University
Department Department of Earth Sciences
Country Netherlands 
Sector Academic/University 
PI Contribution Collaboration with Prof Henk Brinkhuis, Dr Francesca Sangiorgi et al.
Start Year 2010
 
Description Interview and article in New Scientist 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Interview and article in New Scientist
Year(s) Of Engagement Activity 2016
URL https://www.newscientist.com/article/2087207-seabed-core-reveals-how-lush-antarctica-changed-to-icy-...
 
Description NERC Palaeoclimate Forum, Birmingham, UK 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? Yes
Geographic Reach National
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact To identify the requirements and priorities for maintenance and development of the UK National Capability in global paleoclimate modelling over the next 3-5 years, in the context of the wider NERC strategy for Earth System Modelling

see report
Year(s) Of Engagement Activity 2011
 
Description Public Talk at Museum 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Open public talks a Natural History Society Newcastle
Year(s) Of Engagement Activity 2012,2015