The declaration of the "United Nations Decade of Education for Sustainable Development" (ESD), Resolution 57/254, February 2003, provides the best yet occasion for higher education institutions (HEIs) to "green" their curricula. The idea for the Decade emerges from a progression of high-level international conferences, beginning with Stockholm, 1972, that have seen ESD thinking move from general statements of intent to increasingly detailed specifications for action. There has also been a growth in awareness that the changes to the curriculum for sustainable development must suffuse all areas of education provision. They cannot be restricted to the environmental disciplines or "ecoliteracy" modules or even to the classroom, but must be demonstrated by the whole of an HEI's approach to the world. Obstacles to implementation include: funding and perverse subsidies, departmental and disciplinary barriers, ivory-tower traditions in teaching that externalize and objectify the subjects studied and persistence of the obsolete mind-sets of the "industrial age". These barriers may mean that change in HEIs will have to be driven by external processes, such as the transformation of primary and secondary education where the fragmentation of knowledge is less entrenched. However, there now seems to be growing agreement that HEIs should equip all their students with "environmental literacy" and that sustainability should be central to concerns both in HEI curricula and in operational practice.