Abstract

During glacial periods of the Late Pleistocene, an abundance of proxy data demonstrates the existence of large and repeated millennial-scale abrupt climate changes, known as Dansgaard–Oeschger (DO) variability as first identified in Greenland ice core records. These events are characterized by rapid warming from stadial to interstadial conditions with surface temperature changes of up to 16°, sometimes occurring within decades and hence has drawn broad attention within the science and policy-making communities alike. In this seminar, I will update you of the current understanding of the governing dynamics of DO variability, as well as its climatic characteristics. In particular, I will show that gradual changes in Northern hemisphere ice sheets, atmosphere CO2 and Earth’s orbit can directly simulate DO-like abrupt climate changes, providing a dynamic framework to understanding the origin of DO variability across time. These results further suggest that climate background is of great importance on the occurrences of abrupt climate change, of which changes however are not well considered in our future projections by climate models. In this context, some suggestions are provided to help improve reliability of our future projections, avoiding underestimation of potential climate crisis that might occur in near future.