Over the last few decades artists have been engaging in various ways with both the ‘natural’ environment and ecological issues. This paper introduced some of the controversies and debates confronting artists, critics, historians and theorists engaged with these concerns. It explored some problems of definition, and the complex and differing ways in which art – in particular installation art - mediates these issues to a wider audience. After looking briefly at artistic legacies in the work of Smithson, Beuys and others, this paper considered Roni Horn’s site specific work, Library of Water in Stykkishólmur, 2007, Iceland as an installation which can evoke multiple meanings and musings on the effects of climate change.