What is the formal structure of CHANS (Science of Coupled Human and Natural Systems) and how do we develop it as a basic science?  Are the dynamics of human-infiltrated ecological landscapes lawful in interesting ways?  Can insight be gained by broadening CHANS historically, taxonomically, and astronomically to the more general class of intelligent species in ecological landscapes?
As we form our MAHB node at Boston University, we are thinking about the fundamental dynamics of human-natural coupling.  Our primary research instruments to start, are studies of coastal marine area management (e.g. http://www.science2action.org), a working group on nonlinear dynamics, and a team (MIMES-MIDAS) developing computational approaches to the spatial and temporal dynamics of ecosystem service flows and tradeoffs.  We have just received a bit of funding that will facilitate collaboration between our team and the Natural Capital Project, Gaines and Halpern’s group at the Bren School (UCSB) and the ARIES team at Conservation International.  
There is already a good deal of attention to diagnostics for CHANS (e.g. for marine see Coral Health Index, Ocean Health Index, Healthy Reefs Initiative) but we should also be developing a rigorous theoretical framework.  Perhaps that is just “ecology” and we should abandon other pretense, but we suspect that people are strange enough in their ways of dealing with the biosphere that they merit special attention.  You might, e.g. expect that sentience will lead divergently to either very smart or very stupid (Vonnegutian) behavior.  The latter may reduce simply to an individual- vs. group-benefit game.
While most of what has to be done immediately to make society sustainable is already known and simply wants immediate application, it is possible that formal study of CHANS could accelerate the process and generate new options and strategies.