Improve your own "investment environment"

On April 22, we celebrate Earth Day — a day devoted to education and action on environmental issues. As a citizen of the world, you may have a keen interest in protecting your physical surroundings. And as someone trying to reach long-term financial goals, such as a comfortable retirement, you’re probably also interested in improving your investment environment.

So here are a few suggestions:

• Respond to environmental factors. Over the past few years, we’ve had a favorable investment climate, marked by low inflation, low interest rates and generally strong corporate profits. And investors who...