Money/Time/Effort

One observation, perhaps not surprisingly, is that as in many endeavors, money may be an aid. It is useful in purchasing recycled paper goods and prettily packaged kitchen cleansing products.

It procures solar panels and garden implements and Priuses.

(Professor’s joke: If one Prius is good, heck, I’ll take three!”) If one does not have money, time may prove useful; or energy, industry, creativity. And in a pinch (see "A Select Cadre of Undergraduates"), other people.