Indicators have been proposed for the Sustainable Development Goals from the UN's Sustainable Development Solutions Network:
Indicators and a Monitoring Framework for Sustainable Development Goals: Launching a data revolution for the SDGs
Such indicators are, of course, vital if we are to have a handle on success and progress. There is much of interest in here and the whole thing is an informative read – clearly and obviously the product of much careful thought.
I read the Education section  with particular interest and the indicators suggested are mostly sensible as far as they go. For example,
- Primary completion rates for girls and boys
- Percentage of children (36-59 months) receiving at least one year of a quality pre-primary education program
- Percentage of children under 5 experiencing responsive, stimulating parenting in safe environments
- Tertiary enrollment rates for women and men
But when it comes to sub-goal 4.7 which you'll remember is:
"by 2030 ensure all learners acquire knowledge and skills needed to promote sustainable development, including among others through education for sustainable development and sustainable lifestyles, human rights, gender equality, promotion of a culture of peace and non-violence, global citizenship, and appreciation of cultural diversity and of culture’s contribution to sustainable development"
... you find this as the draft indicator:
4.1. [Percentage of girls and boys who acquire skills and values needed for global citizenship and sustainable development (national benchmarks to be developed) by the end of lower secondary] – to be developed
To be developed, indeed. Indicators are usually said to have to be SMART:
Specific – target a specific area for improvement.
Measurable – quantify or at least suggest an indicator of progress.
Assignable – specify who will do it.
Realistic – state what results can realistically be achieved, given available resources.
Time-related – specify when the result(s) can be achieved.
But how SMART is Percentage of girls and boys who acquire skills and values needed for global citizenship and sustainable development (national benchmarks to be developed) by the end of lower secondary?
There are two problems here. One is to identify the skills and values needed for global citizenship and sustainable development; the other is to measure their acquisition (by age 16). The first needs conceptual coherence which I fear is lacking (though attempts will be made). The second needs a mechanism which is wholly lacking. You might think if only there were a secondary subject (compulsory of course) called global citizenship and sustainable development. Only in your dreams, and my nightmares.