The notion of ‘sustainability’ is an old one, even if variations of this term have been used to express the same aspects in various disciplines/sectors and languages (e.g., in forestry, agriculture, and ecology). However, in the age of globalization, especially since the 1980s, its meaning has become much more widely used and interpreted in many contexts. We focus here on research areas (and then science-based policies) grounded on the narrower concept of ‘environmental sustainability’ and the broader concept of ‘sustainable development,’ which have become the foundations of more or less independent scientific disciplines. The former, in essence, means socio-economic development that ‘ab ovo’ takes into account environmental conditions and stringent requirements for protecting the natural environment and (sustainable) use of its resources. In contrast, in the latter approach, the broad system of interactions between social, economic, and environmental processes are considered, albeit more generally, with the priority on (sustainable) social development besides striving for ‘harmony’ among these three pillars/dimensions of (sustainable) development.