What does unsustainable mean?
Unsustainable describes something that cannot be maintained or continued over time without serious consequences. Its common modern use concerns practices, systems, and patterns of consumption or growth that draw on resources faster than those resources can be replenished, damage ecosystems, or weaken the conditions on which future activity depends. The word also has a broader meaning: any arrangement, claim, or situation that is unable to endure. In public debate, the term often carries a warning rather than a merely neutral description, signalling that a system is likely to fail or cause harm if its present course continues. It is common in environmental, economic, and policy contexts in both formal and informal English. The adjective is more specific than simply saying that something is bad because it focuses on the inability of a course of action to remain viable over time. The related noun unsustainability names the condition itself, while sustain and sustainable provide the positive form and the underlying root.
adjectiveUnable to be maintained or continued over time, especially without depleting resources, damaging ecosystems, or undermining future viability.
- Describing a practice, system, or level of activity that cannot continue over time without depleting resources, damaging ecosystems, or causing unacceptable harm.
- Unable to be sustained, maintained, or kept in existence.
"The council rejected the proposal because its reliance on scarce water would make it unsustainable."
"Rapid growth based on finite resources is ultimately unsustainable."
"The judge described the government's argument as financially unsustainable."
The 1987 Brundtland Report helped make sustainable development a global goal; its uncomfortable opposite is progress that quietly consumes the conditions on which it depends.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does unsustainable come from?
The adjective was formed by adding the prefix un- to sustainable. Sustainable in turn combines sustain with the suffix -able; sustain comes through Old French sustenir from Latin sustinere, meaning “to hold up” or “sustain,” ultimately associated with the Latin elements sub- and tenere, “to hold under.” The English family includes related forms such as sustenance and sustainability.
Related word forms
How unsustainable is actually used
Common in environmental, economic, business, and policy discourse, but also used informally for any arrangement that is likely to fail. It is a gradable adjective: it can describe degrees of long-term viability rather than only absolute failure.