Rich Pancost, The School of Chemistry

1. Biomolecules tell us about how climate changed in the past... and how it might change in the future Rich Pancost, The School of Chemistry

2. Outline • A bit about global warming… • What can the past tell us • First, how I study the past • Biological compounds are diverse and some compounds – particularly lipids – can be robust tracers of environmental processes • Analytical chemistry (i.e. CSI science) underpins this research • Studying a global warming event in the past

3. Global Warming

4. How should we talk about climate change? • What do we know? • What do we probably know? • What do we think? • What do we have no idea about?

5. How do we study climate change? • We try to measure changes

6. How do we study climate change? • We try to measure changes • We make computer models of climate

7. How do we study climate change? • We try to measure changes • We make computer models of climate • We study the past

8. What do we KNOW? That Carbon Dioxide and Methane Concentrations in the Atmosphere are Increasing Data from Scripps CO2 Program.

9. What do we KNOW? • CO2 concentrations are higher than they have been for 1000 yrs But how do we know what CO2 was before we could measure it? Direct measurement INDUSTRIAL REVOLUTION

10. What do we KNOW? • CO2 concentrations are higher than they have been for 650 kyr

11. What do we KNOW? • CO2 concentrations are higher than they have been for 20 MILLION years 40 million 8 million 13C versus 12C Pagani et al., 2005 Alkenone-derived pCO2 record

12. Summary That carbon dioxide and methane concentrations are higher than then at any time in the past 1 million years We think that they are higher than at any time in the past 30 million years (alkenone pCO2 proxy; Pagani et al., 2005) We think that they are not at all close to the highest levels in Earth history We think that they are changing faster than at any time in Earth history

13. What do we KNOW • CO2 concentrations are increasing due to fossil fuel burning • CH4 concentrations are probably increasing because of • Increased rice cultivation and ruminant animal agriculture • Natural gas pipeline leakage • Offset by wetland destruction • But also thawing of permafrost? • Increased production due to warmer/wetter climate? • Other greenhouse gas concentrations are also increasing • N2O • CFCs

14. What do we KNOW? That higher CO2 will cause ocean pH to decrease H2CO3 + CO32- 2HCO3- + Ca2+ H2O + CaCO3(s) CO2(aq) Calcium Carbonate Dissolves

15. What do we THINK? That lower pH will adversely affect sealife

16. What do we KNOW? That higher CO2 will cause temperature to increase.

17. Compiled by the Climatic Research Unit of the University of East Anglia and the Hadley Centre of the UK Meteorological Office What do we KNOW? • That elevated carbon dioxide WILL cause warming. • We are fairly certain that it has already caused warming • 0.6°C temperature increase over the past century • 3 hottest years on record are post-1998 • 19 of 20 occurred since 1980

18. What do we KNOW? • That elevated carbon dioxide WILL cause warming. • We are fairly certain that it has already caused warming

19. What do we THINK? That elevated greenhouse gases WILL cause warming of about 4C

20. What do we KNOW? That elevated greenhouse gases WILL cause warming That warming will cause • Sea level rise • Melting of glaciers • Increased aridity in some places and wetter conditions in others • Increased likelihood of extreme weather events • Warming will stress certain biomes

21. What do we THINK? • That warming will cause sea level rise from thermal expansion of the ocean and probably from melting of glaciers

22. What do we KNOW? • Warming will make some places drier and some places wetter

23. What do we KNOW? • There will be more hurricanes

24. So what is the debate all about? • How much will CO2 and CH4 levels increase? • What are the sinks (the ocean, trees, soil)? • How much will temperature increase? • What are the feedbacks? • How much will sea level rise? • How do ice sheets respond to climate? • REGIONAL AND LOCAL EFFECTS • Will some countries be flooded or suffer drought? • How will that affect political stability in some regions? • Or biodiversity? • How will that affect global economics

25. What can we learn from the past?

26. Based on the Permo-Triassic mass extinction event270 Million years ago

27. Has catastrophic (rapid) methane release occurred in the past? What was its impact? What do I do to study it??

28. H H H H H H H C C C C C C H H H H H H Lipid structural variability C H H

29. Lipid structural variability Eucarya Animals Flagellates Plants Microsporidia Fungi Ciliates Slime moulds Bacteria Diplomonads Green non-sulfur bacteria Archaea Sulfolobus Gram positive bacteria Thermotoga Pyrodictium Thermoproteus Nitrospira Cyanobacteria Methanobacterium Pyrococcus Thermoplasma Green sulfur bacteria Archaeoglobus Methanopyrus Halobacterium Methanococcus

30. More 13C Carbonate 98.9% 0 ‰ -8 ‰ CO2(aq) ep d13C values 1.11% -22 ‰ Biomass Kerogen -26 ‰ Lipids Less 13C Methane 13C 12C What can carbon isotopes tell us?

31. Biomarker Geochemistry is built on a foundation of robust analytical chemistry Aim: To isolate a complex extract containing hundreds of compounds and separate it into discrete groupings of compound class amenable to GC or LC analysis Biomarker Geochemistry is built on a foundation of robust analytical chemistry Aim: To isolate a complex extract containing hundreds of compounds and separate it into discrete groupings of compound class amenable to GC or LC analysis Raw sample GC sample

32. Eluent 1 2 3 Sample Analytical Protocol • Soxhlet • Ultrasonication • Bligh-Dyer • Liquid/liquid extraction • Autoextraction Sample Extraction Total lipid extract Residue Chromatography Neutral fraction Acid fraction Polar fraction Appropriate Derivatisation GC-FID GC-MS LC-MS GC-C-IRMS

33. Relative Abundance Retention Time Analyses – Hyphenated Techniques • Flame Ionisation Detector • Mass Spectrometer • Combustion – Isotope Ratio Mass Spectrometer • Thermal Conversion – Isotope Ratio Mass Spectrometer • Gas Chromatograph • Py – Gas Chromatograph • Liquid Chromatograph

34. Long-Term Cenozoic Climate Change Temperature Adapted from Zachos et al., 2001

35. 13C-depleted carbon The Paleoene-Eocene Thermal Maximum Methane! Zachos, James, Mark Pagani, Lisa Sloan, Ellen Thomas, and Katharina Billups (2001). "Trends, Rhythms, and Aberrations in Global Climate 65 Ma to Present". Science292 (5517): 686–693.

36. Questions:1. What triggered the methane release?2. How much methane was released?3. When it became CO2, how much warming did it cause?4. What were the impacts on the climate, environment and life?

37. Questions:1. What triggered the methane release?2. How much methane was released?3. When it became CO2, how much warming did it cause?4. What were the impacts on the climate, environment and life?

38. How much warming did it cause? Zachos et al., 2006

39. Questions:1. What triggered the methane release?2. How much methane was released?3. When it became CO2, how much warming did it cause?4. What were the impacts on the climate, environment and life?

40. 31 29 33 27 25 23 21 Hydrocarbon Fraction Standard Relative Intensity 10 20 30 40 Retention Time Changes in storms? • Back to Tanzanian and New Zealand sites • Lots of biomarkers from plants washed out to sea • But how abundant are they?

41. Abundance mg g-1 Average Chain Length Fatty Acids HMW fatty acids (Higher Plant) Changes in storms? d13C (‰) Depth (m)

42. Conclusions: Implications for future climate change? • Global warming is an important concern, but we need to know more • Insight can come from studying the past • This requires the application of good geological knowledge but new approaches to study the chemistry of the rocks also helps • What have we learned about the PETM • There was a large release of greenhouse gases • This caused climate to warm by about 5C • This appears to have caused an increase in storms • But more dramatic changes – such as those discussed in the article in The Independent – are not observed • We must be cautious in how we use this approach…

43. The Cobham Lignite – a PETM terrestrial setting (With D. Steart, M. Collinson and A. Scott, Royal Holloway) Collinson et al., 2001

44. The Cobham Lignite Pancost, R. D., Steart, D. S., Handley, L., Collinson, M. E., Hooker, J., Scott, A. C., Grassineau, N. J., and Glasspool, I. J. (in press) Terrestrial Methanotrophy at the Paleocene-Eocene Thermal Maximum. Nature.

45. Methanotrophs Heterotrophs The Cobham Lignite

46. Conclusions: The Larger Picture • A wide variety of environmental processes can be studied using lipids and similar biomarkers • Modern: • AOM in the ocean and methanogenesis in wetlands • Petroleum (and other OM) degradation and preservation • Role of OM in releasing arsenic into aquifers • Extreme environments (geothermal springs) • Ancient Extreme Events • PETM • Extinction events • The change from a greenhouse climate to our current climate • This requires the skilful application of state-of-the art analytical chemistry techniques and instrumentation

47. Acknowledgements • Ian Bull and Rob Berstan (and the NERC Life Sciences Mass Spectrometry Facility) • The EU for funding the METROL programme and an EST grant (BIOTRACS) that supports A. Aquilina’s PhD studentship • The NERC for a grant to P. Pearson, R. Pancost and T. Elliott; and for supporting L. Handley’s PhD Studentship • Joyce Singano and all other members of the TDP • The Leverhulme Trust for a grant to M. Collinson, R. Pancost and A. Scott • The NZ Marsden Fund for a grant to E. Crouch, H. Morgans and R. Pancost