Pollen-based quantitative climate reconstructions for Australia, Last Glacial Maximum to present

Studies of palaeoclimate records help us understand how the climate has changed and evolved over the millennia. Climate models can provide explanations for these changes because they allow us to examine the impact of changes in individual climate forcings, such as greenhouse gas concentrations or orbital changes. There are uncertainties in climate model parameterisations, which makes it important to use large-scale quantitative palaeoclimate reconstructions to evaluate the results. Such evaluations have been largely focused on the northern hemisphere; there have been next to no evaluations of simulated climate changes in Australia because of the lack of continent-wide quantitative palaeoclimate reconstructions for model evaluation. This lack partly reflects the need to evaluate the decisions and assumptions involved in making quantitative palaeoclimate reconstructions in the specific context of Australia, as these decisions and assumptions affect the quality of the reconstructions. The aim of my thesis is to provide quantitative climate reconstructions over the past 22,000 years for Australia. In chapter 2, I make a thorough evaluation of the techniques and decisions involved in performing quantitative palaeoclimate reconstructions using the modern analogue technique on modern pollen samples from Australia. The methodology resulting from this chapter is used in chapter 3 to perform reconstructions of regional climates from the Last Glacial Maximum to the present day. Chapter 4 uses these reconstructions to evaluate state-of-the-art climate model simulations of Australia.