The term sustainability refers to an ethical and moral principle of action that relates to the regeneration of natural resources and the mindful use of social and economic resources. Sustainability is an interdisciplinary cross-sectional topic, as it consists of the combination of the topics ecology, economy and social issues. Accordingly, the variety of sustainability topics is large: the fight against poverty, hunger and climate change as well as the provision of quality education and clean water can be found in the diverse range of topics. One of the numerous and sometimes very different definitions comes from the economist Iris Pufé. She defines the term as follows:

“Sustainability describes the use of a regenerable system in such a way that that system retains its essential properties and its stock can be regenerated naturally.” (1)