Ok, this is arguably a bit more advanced than U101 core material but the Autodesk videos on Design for Lifetime and some of the Sustainable Design series are pretty good overviews of some of the main issues.
Here's the intro to Design for lifetime:
Now, apart from the cheesy music, the rest in the series intorduce the different cycles and processes of Green Design, Sustainable Design and Sustainable Innovation (those are T307 terms...).
A really nice way to visualise the lifecycle recycle/reuse pathways is given at the end of this next video (at about 3:46) :
And there are a few other nice ones there for the engineers in the audience...
A word of caution, though. This is very much an introduction to the topic and it definitely glosses over the real-world difficulties in actually trying to implement this in practice.
Engaging in Sustainable Innovation is difficult - necessarily so, it's a complex design thinking problem. To engage in genuinely sustainable innovation requires designers to think beyond their products or specific domains and really think about the wider implications.
For me, though, the simple examples given of designing fixings for assembly and dis-assembly are perfect examples of those little design details that make a huge difference. Just a small bit of detailed, considered design thinking is all it takes.