Descent into the Icehouse
Lead Research Organisation:
University of Southampton
Department Name: Sch of Ocean and Earth Science
Abstract
For the majority (~80 %) of the last 600 million years or so the planet was considerably warmer and wetter than today, and largely ice free - it was in what is known as a 'greenhouse climate state'. The alternate mode, like today, where ice caps blanket both poles - a so called 'icehouse state', is a relatively rare condition for the climate system to be in. Over the last 600 million years the transitions between the two states tend to be rapid and each had dramatic consequences for life on Earth. The most recent of these fundamental climate transitions began around 50 million years ago and culminated at ~34 million years ago at the Eocene/Oligocene boundary with the rapid growth of the Antarctic Ice Sheet. Due to the nature of the rock record, this most recent transition is the best studied and most well documented of the greenhouse to icehouse switches, but nonetheless the processes responsible are still much debated. The most popular hypothesis is that it was caused by a decline in the atmospheric concentration of CO2 - an important greenhouse gas. Although it has been recently confirmed that the final rapid switch at the Eocene/Oligocene boundary was associated with a dramatic decline in CO2, it has also been suggested that CO2 may not have been the main driver of the overall transition. There are instead a number of potential candidates that fall broadly into two camps - either this climate transition was driven purely by processes internal to the Earth (such as uplift of the Himalaya, ocean circulation, or volcanic outgassing of CO2) or it involved some, or all, aspects of the Earth surface, including biology, that can serve to cause and amplify change in a number of important ways. Due to the burning of fossil fuels, atmospheric CO2 concentrations may reach values typical of the greenhouse world of the Eocene by the end of this century. It is therefore becoming imperative to better understand the role of CO2 in driving these natural cycles of Earths climate, and consequently, the principal aim of this proposal is to determine the main driver of this most recent and dramatic switch in climate state. We will achieve this using a multidisciplinary approach that has aspects of both new data collection and computer modelling. The new data we will generate will involve revised estimates of CO2 concentrations and globally widespread estimates of ocean temperature, environmental parameters that cannot be directly determined for the past. We will study the fossil remains of sea-dwelling microscopic organisms, the foraminifers and coccolithophorids. These organisms are very abundant in the mud on the floor of the oceans, providing an invaluable archive of past ocean climate data, and by looking at the chemical composition of their shells or the organic compounds they biosynthesise we can determine how warm or how acidic the ocean was. And from such parameters, we can also deduce how much CO2 was in their environment. Armed with this improved understanding of how the climate system evolved leading up to the greenhouse-icehouse transition we can better investigate the natural processes that caused the change. Given the complex nature of the climate system this is best done with a variety of sophisticated computer modelling approaches. Crucially, it is only by guiding these computer simulations with the new data we have generated that we can isolate which of the myriad of potential processes was responsible for triggering this fundamental shift in climate and better determine how they impacted the evolution of life.
Organisations
Publications
Holden P
(2013)
Controls on the spatial distribution of oceanic d<sup>13</sup>C<sub>DIC</sub>
in Biogeosciences
Lunt D
(2012)
A model-data comparison for a multi-model ensemble of early Eocene atmosphere-ocean simulations: EoMIP
in Climate of the Past
Lunt D
(2016)
Palaeogeographic controls on climate and proxy interpretation
in Climate of the Past
Von Der Heydt AS
(2016)
Lessons on Climate Sensitivity From Past Climate Changes.
in Current climate change reports
Henehan M
(2016)
A new boron isotope-pH calibration for Orbulina universa, with implications for understanding and accounting for 'vital effects'
in Earth and Planetary Science Letters
Edgar K
(2015)
Assessing the impact of diagenesis on d11B, d13C, d18O, Sr/Ca and B/Ca values in fossil planktic foraminiferal calcite
in Geochimica et Cosmochimica Acta
Gutjahr M
(2017)
Very large release of mostly volcanic carbon during the Palaeocene-Eocene Thermal Maximum.
in Nature
Pälike H
(2012)
A Cenozoic record of the equatorial Pacific carbonate compensation depth.
in Nature
Anagnostou E
(2016)
Changing atmospheric CO2 concentration was the primary driver of early Cenozoic climate.
in Nature
Description | We have explored the causes of the "descent into the ice house" - the latest transition from greenhouse climate state to ice house climate state. We have found that changes in the position of the continents was not an important part of this transistion instead it was caused by a decline in the levels of atmospheric CO2. Furthermore, by determining the CO2 content of the atmosphere 34 to 50 million years ago we are able to determine that climate sensitivity was similar in the geological past as encapsulated in climate models. |
Exploitation Route | The results of this project will feed into the next and future reports of the IPCC. these reports have a large reach. We have held a display of the work related to this project at Ocean and Earth Day held at NOCS. This event attracted >3000 members of the public. This research will be of great interest and use to palaeoclimate scientists seeking to understand the climate of the Eocene and for climate modellers seeking to test their models on warm climates of the past. Beyond the academic users (reached through standard publication routes) we have engaged members of the public through our website (url below) and in contributing to a number of well visited blogs (http://www.skepticalscience.com/Carbon-Dioxide-the-Dominant-Control-on-Global-Temperature-and-Sea-Level-Over-the-Last-40-Million-Years.html#commenthead http://www.scienceomega.com/article/759/off-balance-the-co2-and-sea-level-seesaw) Our work was also highlighted in Editors choice in Nature climate change, featured on BBC, Daily Mail and other online sources. |
Sectors | Environment |
URL | http://www.thefosterlab.org/blog/2016/4/25/ancient-marine-sediments-provide-clues-to-future-climate-change |
Description | This research has contributed to the knowledge base regarding the causes and consequences of climate change. It has also directly fed into the latest IPCC report (of which PI Foster was a contributing author) |
First Year Of Impact | 2011 |
Sector | Environment |
Impact Types | Policy & public services |
Title | Boron, oxygen and carbon isotopes, and trace element ratios in planktic foraminifera of different ODP Sites across the Middle Eocene Climatic Optimum |
Description | This dataset contains measurements of d11B, d13C and d18O, as well as the elemental ratios Magnesium/Calcium, Aluminium/Calcium, Strontium/Calcium from planktic foraminifera from six different ODP sites. |
Type Of Material | Database/Collection of data |
Year Produced | 2019 |
Provided To Others? | Yes |
URL | https://doi.pangaea.de/10.1594/PANGAEA.909432 |
Description | Ocean and Earth Day 2013 |
Form Of Engagement Activity | Participation in an open day or visit at my research institution |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Public/other audiences |
Results and Impact | Interacted and answered questions relating to the Descent into the Icehouse and palaeoclimate in general. Visits to website increased |
Year(s) Of Engagement Activity | 2013 |
URL | http://descentintotheicehouse.org.uk/a-fantastic-ocean-and-earth-day-at-national-oceanography-centre... |
Description | Ocean and Earth Day 2014 & 2015 |
Form Of Engagement Activity | Participation in an open day or visit at my research institution |
Part Of Official Scheme? | No |
Geographic Reach | Regional |
Primary Audience | Public/other audiences |
Results and Impact | The general public were engaged with at the National Oceanographic Centre Ocean and Earth Day. The activity involved a stall where future climate change was put in it geological context. |
Year(s) Of Engagement Activity | 2014,2015 |
Description | Public Engagement |
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 | Media (as a channel to the public) |
Results and Impact | Following the publication of Foster et al. 2017 in Nature Communication we engaged with the media, through The Conversation (https://theconversation.com/we-are-heading-for-the-warmest-climate-in-half-a-billion-years-says-new-study-73648) which has >50K reads. Our work was also picked up by the mainstream media (e.g. https://www.theguardian.com/environment/climate-consensus-97-per-cent/2017/apr/17/humans-on-the-verge-of-causing-earths-fastest-climate-change-in-50m-years) and popular science literature (https://www.newscientist.com/article/2126776-co2-set-to-hit-levels-not-seen-in-50-million-years-by-2050/) and podcast (https://www.scientificamerican.com/podcast/episode/climate-420-million-years-ago-poised-for-comeback/) |
Year(s) Of Engagement Activity | 2017 |
URL | https://theconversation.com/we-are-heading-for-the-warmest-climate-in-half-a-billion-years-says-new-... |
Description | Public engagement via involvement in article for National Geographic Magazine |
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 | After appearing in the magazine I was contacted by several members of the public for dicussion Following my featuring in National Geographic the following additional activities arose: Blog for Skeptical Science (http://www.skepticalscience.com/Carbon-Dioxide-the-Dominant-Control-on-Global-Temperature-and-Sea-Level-Over-the-Last-40-Million-Years.html#commenthead) Blog for Science Omega (http://www.scienceomega.com/article/759/off-balance-the-co2-and-sea-level-seesaw) |
Year(s) Of Engagement Activity | 2013 |
URL | http://descentintotheicehouse.org.uk/as-the-planet-warms-the-sea-rises-how-will-we-face-the-danger-o... |
Description | Royal Society Discussion Meeting on hyperthermals |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | We held a Royal Society discussion and satellite meeting on Hyperthermals: rapid and extreme global warming in our geological past. The meeting was open to the public and we had over 100 attendees. |
Year(s) Of Engagement Activity | 2017 |
URL | https://royalsociety.org/science-events-and-lectures/2017/09/hyperthermals/ |
Description | Royal Society MP-Scientist pairing scheme 2011-12 |
Form Of Engagement Activity | A formal working group, expert panel or dialogue |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Policymakers/politicians |
Results and Impact | PI Gavin Foster was involved with the Royal Society MP-Scientist pairing scheme. Gavin was paired with MP for Romsey and Southampton North Caroline Nokes. Caroline visited NOC in Feb 2012, Gavin went to westminster in Nov 2011. |
Year(s) Of Engagement Activity | 2011,2012 |
URL | http://descentintotheicehouse.org.uk/caroline-nokes-mp-visit-at-noc/ |
Description | School visits (as part of University of Bristols ChemLabS outreach program) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Schools |
Results and Impact | The presentation sparked questions and discussion afterwards Nothing reported |
Year(s) Of Engagement Activity | 2014 |
Description | Scientists on the Road |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Schools |
Results and Impact | Children asked many questions of the scientists involved. Increase in website hits and follow up communication |
Year(s) Of Engagement Activity | 2013 |
URL | http://descentintotheicehouse.org.uk/scientists-on-the-road-travel-to-science-festivals/ |