Compared to sustainable development, sustainability is mostly examined in a completely different context by representatives of science, even though the concepts of sustainability and sustainable development are sometimes used synonymously even in academic literature.

Based on a review of relevant literature sources, it can be concluded that the concept of sustainability is not uniform, but rather a dynamically changing and expanding one. The experts dealing with the topic try to explore the characteristics of the definition of sustainability based on the specific aspects of different scientific fields.

However, most authors agree that the issue of sustainability is multi-, inter- and transdisciplinary in nature and that most disciplines need to contribute directly and indirectly to answering the complex questions of sustainability. Elliott specifically emphasises that the impact needed to effect real, systemic change can only be made through interdisciplinary integration.2

Some authors provide a definition of sustainability based on the complex systems theory,3 for example according to Walker and his co-authors, the sustainability of social-ecological systems depends on the trichotomy of flexibility, adaptability and transformability.4According to another theory, sustainability is a characteristic of networked systems that is transmitted through networks in complex organisational systems, changing (increasing or decreasing) at each step.5

In recent years, analytical discourse on sustainability has been characterized by the debate between two perspectives: strong and weak sustainability. Representatives of the former support the full preservation of natural values in the face of economic development. Strong sustainability is primarily a specific principle of ecological economics, which is based on the assumption that the economy is a subsystem of nature, which imposes limits on the physical growth of the economy.6 This also means that human activities and economic systems must be operated within the limits of the planet. The substitutability of natural capital and man-made capital has ultimate limits and at least a part of natural capital must be maintained in order to achieve sustainability.7

On the other hand, for representatives of weak sustainability, the maintenance of economic systems is the priority.8 The basic premise of weak sustainability is that man-made and natural capitals can be replaced and that both economic growth and sustainable use of resources can be realized, that is, permanent prosperity becomes attainable over time.9 This so-called Porter hypothesis deserves special attention because it assumes that there can be win-win solutions for both the economy and the environment.10 This concept is closer to neoclassical economics, according to which the inefficient use of natural resources is the cause behind environmental problems.11

In some contexts, sustainability also means that certain institutions of human society (states, organisations, operating mechanisms) are able to survive in the long term. That is, their existence is not unsustainable. According to Richard Heinberg, it is reasonable to treat sustainability as a kind of reference frame for determining the time horizon of sustainability.12 In this context, it includes a global spatial dimension and an infinite temporal dimension that requires consideration of long-term impacts and global interactions.

The mention of future generations in Heinberg’s work may mean two things: that sustainability can be interpreted within long time frames; and that the living conditions and needs of the upcoming generations must also be taken into account during evaluation.