Less alarmism and more solutions: That's the approach of Worldchanging (Abrams, $37), an environmental encyclopedia with an optimistic point of view. Are you looking for clear-eyed visions of a cleaner, more efficient future, one where energy bills are affordable and feeding a tuna fish sandwich to your toddler is less risky than letting him wade in shark-infested waters? Enter here. An outgrowth of the weblog of the same name, Worldchanging's 596 pages are divided into seven sections, broadly titled with names like Shelter, Planet, and Stuff.

Don't expect to flip to "H" to read up on hydrogen cars; you'll need the table of contents and the index to locate topics of interest. But simply perusing the book can be rewarding. Who would have thought to look for a device called a corporate fallout detector? It's a "blend of performance art, ethics, and technology" that scans bar codes and emits a clicking noise: the more clicks, the greater the environmental sins of the product's manufacturer. You can't actually buy one of these gizmos, but it's still good for a laugh and a glimmer of hope for a saner tomorrow.