Applied sustainability is the application of science and innovation to meet human needs while indefinitely preserving the life support systems of the planet.
A more refined definition would be called just applied sustainability: the application of science and innovation to ensure a better quality of life for all, now and into the future, in a just and equitable manner, whilst living within the limits of supporting ecosystems.
The relationship between applied sustainability and sustainability is analogous relationship between applied science (engineering) and basic science. Whereas science is the effort to discover, understand, or to understand better, how the physical world works, with observable physical evidence as the basis of that understanding. Applied science is the application of knowledge from one or more natural scientific fields to solve practical problems.
Applied sustainability is essentially sustainability engineering – by utilizing natural laws and physical resources in order to design and implement materials, structures, machines, devices, systems, and processes that meets human need while preserving the environment forever. Applied sustainability is made up of work in engineering, policy, and education – whatever methods are necessary to conserve the world for our children.
Sustainability, itself, is a term that is often confused because in its most basic form it is a characteristic of a process or state that can be maintained at a certain level indefinitely. When used in the context of development, as sustainable development, it is a pattern of resource use that aims to meet human needs while preserving the environment so that these needs can be met not only in the present, but in the indefinite future. The most evolved definition of sustainability is that of just sustainability - “the need to ensure a better quality of life for all, now and into the future, in a just and equitable manner, whilst living within the limits of supporting ecosystems”.
Appropedia, and the appropriate technology housed here, is a primary example of applied sustainability.