The need to define sustainability and identify meaning and scientific foundations of the concept has been compelling during the last decades. Systems approach has been largely contributing to describe the reality in which we live and understand how to measure the progress of human action towards sustainable development. Professor Sven Erik Jørgensen directly and indirectly stimulated scientific advancements in the field of sustainability definition and evaluation. His work, especially focussing on the wide view of systems sciences, of which he has always been one leading promoter, was also interestingly devoted to study the relationships between human behaviour, society, policy, education and the environment at the global level.

Inspired by this view, we present and discuss a list of aspects that can be crucial in the attempt of evaluating the sustainability/unsustainability of our development models, and reflecting the multidimensional and interconnected nature of the concept. In particular, we focus on the global dimension of sustainability; the need of holistic approach, that considers relations within and among different systems at different scales; the use of intensive and/or extensive indicators for investigating sustainability; and, in more practical terms, the need of data and knowledge to feed evaluation tools. The focus on these needs will contribute to a better understanding and diffusion of the concept of sustainability under a systems perspective.

在过去的几十年中，定义可持续性，确定概念的含义和科学基础的需求一直很迫切。系统方法在很大程度上描述了我们所生活的现实，并了解了如何衡量人类在实现可持续发展方面的进展。Sven ErikJørgensen教授直接和间接地刺激了可持续性定义和评估领域的科学进步。他的工作特别是专注于系统科学的广泛视野，他一直是系统科学的主要推动者，他的工作也有趣地致力于研究全球范围内人类行为，社会，政策，教育与环境之间的关系。

受此观点启发，我们提出并讨论了一系列方面，这些方面对于评估我们的开发模型的可持续性/不可持续性以及反映概念的多维性和相互联系的性质至关重要。特别是，我们专注于可持续性的全球层面；整体方法的需要，该方法考虑了不同规模下不同系统内部和之间的关系；使用密集和/或广泛的指标来调查可持续性；从更实际的意义上讲，需要数据和知识来提供评估工具。在系统的角度下，对这些需求的关注将有助于更好地理解和传播可持续性的概念。