Scientific literacy is key to understanding sustainability. Concepts like concentrations, thresholds and feedback loops are probably the most important concepts we can get across to our kids, and frankly, much of the adult US population!
Data literacy and media literacy are also critical. People can manipulate data to try to prove their own perspective. This 4 min animated Ted video shows you what to look for in a graph to see if it is (or someone is being) misleading.