GEOGRAPHY

Terrestrial vegetation dynamics feedback enhances the Holocene rapid climate change event


As a typical interglacial period, the Holocene is generally a period of relatively warm and stable climate, but it is constantly interrupted by a series of rapid (or extreme) climate change events, threatening the human living environment. The Holocene has accumulated at least 10 rapid climate change (RCC) events. However, the explanation of the causal mechanism of Holocene RCC events has been controversial.

Recently, Li Xinzhou, a researcher-level senior engineer and his collaborators at the Institute of Earth Environment, Chinese Academy of Sciences, collected and sorted out a variety of high-resolution geological records in East Asia, and used the public earth system model CESM to complete four sets of Holocene transient numerical experiments with dynamic vegetation (DV), non-dynamic vegetation (nDV), orbital forcing (ORB) and vegetation forcing (VF), and carried out “simulation-record” direct comparison. The results show that the DV experiment can reproduce the 8 RCC events of the Holocene in northern China, and the occurrence time and change amplitude are very consistent with the geological record, and the simulation results show that these 8 RCC events are common in the northern hemisphere, while other experiments only simulate one or two rapid climate change events, or there is a large deviation between the time of rapid climate change events caused by other forcing factors and the geological record.

Percentage change in annual precipitation for 8 Holocene RCC events and their collective mean (MRE). (Photo courtesy of the Institute of Global Environment)

This study suggests that the dynamic evolution of terrestrial vegetation and its feedback is a key factor in the occurrence of Holocene RCC events. The difference between DV and nDV tests showed that dynamic vegetation feedback could cause a significant decrease in precipitation and a significant drop in temperature during almost all RCC events. In this paper, the mechanism explanation of RCC event change and its close relationship with terrestrial vegetation feedback is given from the aspects of dynamic degradation of terrestrial vegetation, anomalous albedo on the surface and balance of terrestrial radiative balance. It is worth mentioning that forcing factors such as the dynamic evolution of the high-latitude ice sheet and the debris (freshwater injection) of the North Atlantic ice raft were not considered in this study, but the DV experiment accurately simulated 8 RCC events in the Holocene, indicating that land vegetation, as a key factor in the exchange of matter and energy between land and atmosphere, its dynamic anomalies and their feedback to climate may play a key regulating role in the long-term evolution of climate, and should be fully considered in future climate predictions.

The above research results were recently published online in the internationally renowned journal npj Climate and Atmospheric Science, and Li Xinzhou was the first/corresponding author of the paper. This work follows the previous paper published in Communications Earth & Environment to propose that dynamic vegetation feedback causes long-term evolution of Holocene precipitation, and to strengthen the rapid climate change events of the Holocene for the dynamic evolution of terrestrial vegetation and its response to climate. (Source: Yan Tao, China Science News)

Related paper information:https://doi.org/10.1038/s41612-023-00457-5



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