A holistic perspective on Earth system science

In a white paper published by a multidisciplinary team of top scientists in China, Earth system is defined to encompass both internal and external geospheres from solid Earth system through surface Earth system to Sun-Earth space system. Thus, Earth system covers a vast range from the core, mantle and crust through hydrosphere, biosphere and atmosphere to the outer space affected by Sun, and spans from the formation of continental crust through the formation of mountain ranges to the present landscapes in terms of time. Although significant progress has been made in studying the individual disciplines of Earth science, there is still insufficient understanding of the overall behavior and interactions between geospheres and subsystems, thus facing challenges of different types and levels.

Earth system science aims to decipher mutual transmission and coupling relationships in both energy and matter between the geospheres and subsystems at microscopic to macroscopic scales. It is an interdisciplinary field that focuses not only on the physical, chemical and biological interactions between various geospheres but also on the properties, behaviors, processes, and mechanisms of the entire Earth and its spheres. It is characterized by its globality and unity with a holistic view and a systematic view at multiple scales in both space and time.

The solid Earth system is composed of the crust, mantle, and core. Plate subduction and mantle convection are two of the most efficient means to transfer material and heat in top-down and bottom-up ways, respectively. Existing observational techniques struggle to penetrate deep into the mantle, making direct observation and data acquisition difficult. The extreme environments within Earth, such as high temperature, high pressure, and strong magnetic fields, also pose great challenges to observational equipment and scientific experiments.

The surface Earth system is rich in complex interactions and feedback mechanisms among its geospheres (such as atmosphere, hydrosphere, biosphere, pedosphere and lithosphere), leading to difficulties in understanding of its overall behavior and long-term evolution. Its behavior is significantly affected by biological activities, including human activities. The coupling between the internal and external Earth systems is complicated, leading to difficulties in distinguishing and quantifying the effects of geospherical interactions and biological activities on global environmental changes.

The Sun-Earth space system involves multiple physical processes such as solar activity, Earth’s magnetic field, atmosphere, and space weather. Solar activity significantly affects the Earth’s space environment, but existing observational and reconstruction methods and prediction models still lack precision and timeliness. It is important to improve the prediction capability of solar activity and forecast the impact of space weather disasters. However, it is challenge to decipher these factors at different scales through establishing coupled models of multiple physical processes.

Because the various processes and phenomena within and between these three Earth subsystems often span multiple scales in both space and time, their behaviors generally exhibit strong nonlinear characteristics. As a consequence, understanding these processes and products becomes complex and variable, giving rise to great challenges for theoretical modelling and numerical simulation. Therefore, the study of Earth system science requires in-depth interdisciplinary integration to jointly reveal the basic laws and operating mechanisms of Earth system.

See the article:

Zheng Y F, Guo Z T, Jiao N Z, Mu M, Piao S L, Fu S Y, Yang D H, Zhu M Y. 2024. A holistic perspective on Earth system science. Science China Earth Sciences, 67(10): 3013–3040, https://doi.org/10.1007/s11430-024-1409-8

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