Nonlinearities in the Earth system

The complex non-linear physical, chemical, and biological interactions among the components of the Earth System are becoming an increasingly important focus in global change research [1]. These interactions between atmosphere, oceans, ice, and land are driven externally by the solar input of heat, and internally by geologic activity and the myriad processes that control the behaviour of each sub-system (Figure 1). Human activity is an integral component of these interactions. At the 3 rd IGBP Congress, Banff, Canada, a working group entitled “Development of Earth System models to predict non-linear responses/ switches ” was convened to review our understanding of this nonlinear system. The session built upon an earlier IGBP workshop entitled “Non-linear responses to global environmental change: critical thresholds and feedbacks”, held at Duke University, North Carolina, USA, in May 2001. At these meetings, a diverse group of scientists confirmed that each component of the Earth System itself includes complex non-linear feedbacks, in addition to the non-linear interactions between the components. This article draws on the above two meetings to discuss the implications of Earth System complexity for Earth System research, modelling, and prediction. The complexity of the Earth System’s behaviour makes it extremely difficult to accurately forecast the future of the Earth System, and presents a major challenge to the global change research community. New mathematical approaches to assess non-linear behaviour have been explored in recent years to address the problem. Such approaches are taking advantage of advances in the theory of chaotic behaviour and deterministic and stochastic predictability. The goal is to develop techniques for prediction of a system in which many of the components, processes, and thresholds are uncertain or even unknown. As such, one of the main conclusions of the above-mentioned IGBP meetings was the recognition that the evaluation of key vulnerabilities and sensitivities of the Earth System to human

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.