How to be an 'environmental' investor

Next week, we observe the 45th anniversary of Earth Day. Since its inception in 1970, Earth Day has inspired millions of people to take action to improve the environment. But the lessons of environmentalism can also be applied to other areas of life — such as investing. Specifically, as an investor, you may well want to follow the “three Rs”: reduce, reuse and recycle.

Let’s see how these environmental themes can be applied to your investment habits:

• Reduce — Many of us probably own more things than we really need. In fact, if all the other people on Earth used as much “stuf...