Today's editorial  in the New York Times, nominally about the "Occupy Wall Street" movement, is well worth reading.
In terms of understanding the sustainability challenge we all face, it's grossly incomplete. (Of course, so is any writing shorter than book-length-plus-appendices.) But as a brief account of the economic, and the resulting socio-political, unsustainabilities that obtain, it's pretty good. Thus, it implies some of the societal constraints under which we must undertake to solve environmental problems. Or, if you prefer, the societal problems we need to solve while operating within a strict set of environmental constraints. And, of course, it focuses only on this society, this (national) economy.
Greenhouse gases are only one element of the real problem set. And, perhaps, not even the element it's most important our students understand.