Hey Mr. Green,
What's the most ecofriendly way to feed a fireplace? —Joan in Santa Fe, New Mexico

Mr. Green answers:
Fueling your fire with sustainably harvested or dead trees may be the best option, but be sure to ignite them in an EPA-approved fireplace insert or wood stove to slash those nasty particulate emissions. And sometimes, as in drier areas like yours, it's better to let dead trees rot; forests may need nutrition from these arboreal corpses.

If you're still using a dirty old traditional fireplace, opt for artificial logs made of materials that might otherwise have been wasted, such as sawdust and wood chips. Because these elements are squeezed together under pressure, the logs are denser and drier than wood, so they burn cleaner and hotter while producing less soot.

Look for manufactured logs made of wood only, and avoid those that contain paraffin, a petroleum-based byproduct with dubious emissions quality. One of the biggest brands, Duraflame, has made its logs greener by phasing out all petroleum-based waxes. Some other options include recycled-paper briquettes (simplefire.com) and logs made of recycled boxes (cleanflamelog.com) and used coffee grounds (java-log.com). If only they smelled like a fresh-brewed espresso.