In 1979, Her Majesty’s Inspectors of Schools [HMI] published a supplementary working paper on environmental education as part of their reporting on Curriculum 11 – 16 in England. The paper was written after Tbilisi, and it references both this and other Unesco and Council of Europe publications (1976 to 1978), as well as influential UK documents from the Schools Council, NAEE, the government, and authors such as Carson, Watts, and Martin & Wheeler. The document begins by stating that environmental education is to be regarded …
as a function of the whole curriculum, formal and informal … furthered through established subjects and by courses in environmental science and environmental studies which in varying degree are interdisciplinary. There is a common purpose in these to foster an understanding of the processes and complex relationships which effect environmental patterns, together with a sensitivity to environmental quality and a concern for the wise and equitable management of the earth's resources.
So, there's both a liberal education approach (foster understanding) and a more value-orientation:
foster a ... concern for the wise and equitable management of the earth's resources
This seems remarkably similar to the focus and phraseology of the 2011 expert group report to DfE that an aim of the curriculum ought to be to …
promote understanding of sustainability in the stewardship of resources locally, nationally and globally.
Perhaps they had a copy to hand – or is this just an idea coming round again?