Planetary Health (ii) (and the need for a global conceptual framework)

I have 5,000 words drafted on Hodges' model and threshold concepts, for which I've yet to find a home. Staying with the previous post's theme of planetary health the paper includes the following: 

A decade ago Groffman, et al., (2006) stated that ecological thresholds can be 'troublesome' in being important but in having no practical application. Threshold concepts are not, however alone; there are also threshold questions (Halldén and Lundholm, 2009). The answers to these questions are critical to global sustainability and planetary boundaries (thresholds) - an ongoing research effort (Rockström et al., 2009).

Groffman, P., Baron, J., Blett, T., et al. (2006). Ecological Thresholds: The Key to Successful Environmental Management or an Important Concept with No Practical Application? Ecosystems, 9(1), 1-13.

Halldén, O. & Lundholm C. (2009). 25-30 August. Conceptual Change and the Complexity of Learning. Threshold Questions, Meaning making and Contextuality. Paper presented at the 13th conference European Association for Research on Learning and Instruction, Amsterdam, Holland.

Rockström, J., W. Steffen, K. Noone, Å. et al. (2009). Planetary boundaries: exploring the safe operating space for humanity. Ecology and Society. 14(2): 32. [online] URL: http://www.ecologyandsociety.org/vol14/iss2/art32/

See also:

Jones, P. (2008). Exploring Serres’ Atlas, Hodges’ Knowledge Domains and the Fusion of Informatics and Cultural Horizons, IN Kidd, T., Chen, I. (Eds.) Social Information Technology Connecting Society and Cultural Issues, Idea Group Publishing, Inc. Chap. 7, pp. 96-109.