School of Earth and Environment, University of Leeds, UK

Introduction and the Importance of Palaeoclimatology

Prof. Alan M. Haywood

• Inspiration and approaches to palaeo

• Climate evolution - the last 80 million years

• On the shoulders of Giants...

• Problems in a post-pioneer era

• Data and model uncertainties

Talk Outline

Why Palaeoclimate?

Why?

• Uncertainties highlighted in climate prediction involve aspects of the climate that have changed in the past (e.g. ENSO).

• Palaeoclimatology can assess whether these changes are consistent with current theories of the climate system and if not, why not.

• Palaeoclimate provides a unique test-bed for models that project large changes in the future to be evaluated using true out-of-sample tests of comparable magnitude.

Inspiration and approaches to palaeo- ENSO as an example

• Shift in frequency/amplitude of El Nino

• Attribution to warming due to anthropogenic emissions of greenhouse gases?

- Policy relevant tipping elements

Adapted from Lenton et al. (2008).

Inspiration and approaches to palaeo

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10Climate Sensitivity Earth System Sensitivity

Lunt et al. (2010). Nature Geoscience

Inspiration and approaches to palaeo - Climate and Earth System Sensitivity

Last 80million yrs

Combining data and modelsa challenging relationship at times...

Modelling: On the Shoulders of Giants!The great pioneers e.g.:

Eric Barron Tom Crowley John Kutzbach Paul Valdes

• Established many of the parameters and attributes of the scientific environment in which we work

• We must now add to the tapestry and unravel complexities/contradictions and understand and

quantify uncertainties.

• Reproducing the observed record of variability and change• Reconciling palaeoclimate simulations with climate archives• Assessment of climate and earth system sensitivity

Palaeoclimatology: Grand Challenges