What? The northeastern part of the Qinghai-Tibet Plateau has entered the "Early Anthropocene"! ?

The relationship between environmental evolution and human activities in the northeastern Qinghai-Tibet Plateau over the past thousand years has attracted much attention from the academic community, which is crucial to understanding the beginning of the global "Anthropocene". The School of Geographical Sciences of Nanjing University of Information Science and Technology, in collaboration with the Institute of Tibetan Plateau Research and Nanjing Institute of Geography and Lake Research of the Chinese Academy of Sciences, analyzed representative paleoclimate and paleoenvironmental records in the northeastern Qinghai-Tibet Plateau and found that in the past 200 to 300 years, the impact of human activities on the environment has gradually surpassed climate factors, reaching a significant peak after AD 1950. Lake sediment indicators show that the increase in human activities has led to rapid environmental changes, which has "decoupled" the coupling relationship between climate and ecological environment. The study also established a model to determine the stratigraphic boundary of the plateau Anthropocene, pointing out that the plateau environment is transitioning from the late Holocene to the early Anthropocene. After entering the "Early Anthropocene", the signals of human activities in various sediments increased, while the paleoclimate signals gradually blurred and disappeared. The research results were published in "Science China: Earth Sciences", providing a new perspective for understanding the impact of human activities on the plateau environment.

As the impact of global human activities on the earth's environment becomes increasingly significant, how to define and evaluate the Anthropocene has become a focus of scientific attention. As the earliest human settlement area in the plateau, the interaction between environmental evolution and human activities in the northeastern Qinghai-Tibet Plateau provides a valuable research sample for exploring the Anthropocene. This paper aims to reveal the characteristics of environmental changes in the region over the past thousand years and their connection with human activities through high-resolution paleoclimate and paleoenvironmental records, and to conduct an in-depth study of the impact of these changes on the beginning of the Anthropocene.

The paper first reviewed the history of human activities in the northeastern Qinghai-Tibet Plateau and found that the region has undergone significant socioeconomic changes since the mid-Qing Dynasty. Subsequently, the research team selected a variety of sedimentary records including lake sediments, ice cores, and peat, and extracted key environmental indicators such as organic matter content and pollen A/C ratio to analyze the environmental evolution process in the region. By comparing climate change and human activity intensity in different historical periods, the dynamic changes in the impact of human activities on the environment were explored.

This paper uses a data integration method to conduct a comprehensive analysis of various sedimentary records in the northeastern Qinghai-Tibet Plateau. First, sedimentary sequences with a time resolution of 20 to 30 years were screened to ensure that the details of environmental changes can be captured. Subsequently, all data were standardized using Z-score standardization and low-pass filtering techniques to eliminate dimensional differences and highlight long-term trends. Finally, by calculating the arithmetic mean, an integrated curve containing 15 indicators was generated to reflect environmental changes in the past thousand years (Figure 1).

Fig. 1 Comparison of the integrated data of this study with changes in regional and global environmental indicators. (a) Oxygen isotope curve of stalagmites in Wanxiang Cave on the northeastern edge of the Qinghai-Tibet Plateau, representing the intensity of Asian monsoon activity; (b) z-score integrated curve of organic matter content index and A/C index in lake sediments in the northeastern Qinghai-Tibet Plateau; (c) Population change trend in eastern Qinghai; (d) Change in the proportion of coarse particles in Sugan Lake sediments in the northeastern Qinghai-Tibet Plateau, representing the frequency of sandstorms in the study area; (e) Changes in global atmospheric methane concentration in the past thousand years; (f) Changes in carbon dioxide concentration; (g) Changes in global population in the past thousand years

The study found that over the past thousand years, the impact of human activities on the environment in the northeastern Qinghai-Tibet Plateau has gradually increased, especially in the past 200 to 300 years, when its impact has surpassed that of climate factors. Since the 1950s, physical and chemical indicators related to human activities have shown an exponential growth, marking a significant manifestation of the global "great acceleration" phenomenon in the region. In addition, the study also found that the coupling relationship between climate factors and environmental changes has gradually decoupled under the influence of human activities, indicating that the region has entered the "Early Anthropocene" stage (Figure 2).

Figure 2 The start time of the Anthropocene and the stratigraphic boundary model in the plateau region. The orange dashed line in the figure represents the beginning of the Anthropocene, and the bold gears represent the dominant factors affecting environmental changes at different stages. The arrows on both sides of the climate conditions represent the ups and downs of the climate, and the arrow on the right side of the population represents the monotonic increase process.

The innovation of this paper lies in the comprehensive analysis of various sedimentary records in the northeastern Qinghai-Tibet Plateau, and the use of data integration methods to reveal the dynamic relationship between environmental changes and human activities in the past thousand years. In addition, the study also proposed an Anthropocene stratigraphic boundary model suitable for plateau areas, providing a new perspective and method for global Anthropocene research. The highlight of the paper lies in its detailed data support and in-depth theoretical analysis, which provides a valuable reference for global environmental change and Anthropocene research. By revealing the characteristics and mechanisms of environmental changes in the region, it provides a scientific basis for formulating environmental protection policies and responding to global climate change.

For more details, please read the original article

Pu Y, Wei XQ, Liu JB, Zhang K, Li BB, Wei ZD, Zhang MM, He T, Wang YJ, Shao XH. 2024. Relationship between environmental evolution and human activities in northeastern Qinghai-Tibet Plateau over the past millennium and its implications for the beginning of the Anthropocene. Science China: Earth Sciences, 54(11): 3574–3586