This paper argues that there is a crucial link between language and sustainability and explores in particular how the evolution of certain characteristics and functions of human language are related to it. The emphasis is on how the principal technologies of language - speech and writing - are related to our ways of being and doing, reflecting on and acting in the world and the consequences of this relationship in terms of the sustainability of our existence. The emergence of writing and its correlation with nominal language are seen as particularly significant developments in how we represent reality and thereby risk following unsustainable pathways.