Join us for a seminar with Dr. Zhengyu Liu, Byrd Center PI and Department of Geography Professor. The seminar is titled "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. A new analysis of tropical-subtropical mean-annual SST reconstruction produces a cooling trend, after using a method to filter the seasonal bias signal in the original annual SST reconstruction. The conundrum is likely resolved over the ocean.
