Advice on travel, technology, and recycling mythology

In the March/April 2007 issue of Sierra, Mr. Green waxes mathematical on the carbon dioxide emissions generated by air travel, gives computer users some energy-saving rules to live by, and dispels rumors about recycled paper.

Curious, concerned, or just generally confused about environmental issues of all stripes? Send your thoughts and questions directly to Mr. Green, or weigh in in the comments section.