Distinguished Lecture - Global warming or global cooling in the last 10,000 years? – the Holocene temperature conundrum

Most previous temperature reconstruction of global annual temperature shows an early Holocene warming followed by a cooling trend through the middle to late Holocene. This global cooling is puzzling because it is opposite to the expected and simulated global warming trend due to the retreating ice sheets and rising atmospheric greenhouse gases, leading to the Holocene temperature conundrum. 

Our critical re-examination of this apparent contradiction between the reconstructed cooling and the simulated warming points to potentially significant biases in both the seasonality of the proxy reconstruction and the climate sensitivity of current climate models. In this lecture, Professor Liu will discuss a new analysis of tropical-subtropical mean-annual SST reconstruction, which produces a cooling trend after using a method to filter the seasonal bias signal in the original SST reconstruction – and the conundrum is likely resolved over the ocean.

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Speaker Professor Zhengyu LIU

Max Thomas Professor of Climate Dynamics, The Ohio State University

Professor Zhengyu Liu is the Max Thomas Professor of Climate Dynamics and Professor of Byrd Polar and Climate Research Center in The Ohio State University.

Professor Liu is the Fellow of American Association for the Advancement of Science, American Meteorological Society and American Geophysical Union. He also received Vilas Associate Award-UW-Madison in 2000-2003.

His research focuses on climate dynamics, ocean-atmosphere-land interactions, dynamics of oceanic circulation, paleoclimate modelling, earth system modelling. Professor Liu has 380 publications and 77 AGU journals, on past climate, climate dynamics, climate variability and ocean-atmosphere interaction, and climate-ecosystem interactions.