A brief review of the coupled human-Earth system modeling: Current state and challenges

Human activities have profound impacts on climate and ecosystems via fossil fuel use and land-use changes, and environmental changes in turn affect human society. Due to strong bidirectional links between the human society and the environment, there is a need to understand the complex dynamics of coupled human-Earth systems (CHES) for mitigation and adaptation purposes. In this paper, four main feedback links between human and Earth systems are identified, and the simulated impacts of some of these feedbacks on natural and social variables based on CHES models are examined. To better understand the current state of CHES modeling, the model development history is briefly described including the implementation of several different coupling forms and approaches. The CHES models are still in a quickly developing stage facing several gaps and challenges in theoretical understanding and modeling techniques. To meet these gaps and challenges, more studies across different research communities with truly interdisciplinary collaboration are required.