I've now had time to read UNESCO's Issues and trends in Education for Sustainable Development [A. Leicht, J. Heiss and W. J. Byun (eds)]. Chapter 10, Monitoring ESD: lessons learned and ways forward by Ashley Stepney Lockhart (pps. 215 – 232) stood out for me, particularly this on p. 219:
"Much of what informs better policy-making and practice is the result of evaluation of a specific, contextualized educational process, not simply test scores. Lower test scores may provide information about a group of learners’ general knowledge and skill in ESD, if the questions truly correspond to common principles in the subject and not a supposed proxy version such as geoscience. [FOOTNOTE]. Lower test scores may suggest that changes are needed to inputs, but do not provide clues as to how to make those changes or the underlying motivation, aside from improving test scores. Improving test scores has little to do with real ESD learning or advancing sustainable development; test scores are only an indication of competence."
"It is not appropriate to equate subjects that may teach about the natural environment with ESD. For example, in geoscience or earth science, learning focuses on areas such as plate tectonics and physical and chemical processes from inside the Earth’s surface that affect its crust. It does not focus on human-made problems such as climate change, etc."