A xeri-what? If you live in an arid region, planting a xeriscape-landscaping with plants...

Think of a photocopy of a photocopy of a photocopy. With every successive copy, the quality deteriorates. That is essentially what happens when some products-plastics, for instance-are recycled: the process "downcycles" them into an inferior new material. And because it degrades every time, that material will eventually become waste, even though you've tried mightily to keep it out of a landfill by recycling. A plastic soda bottle, for instance, cannot be recycled to make another soda bottle; instead, the lower quality plastic that results is suitable for only limited purposes, including plastic lumber, carpet padding, and fleece jackets (and those resulting products are rarely, if ever, recycled themselves). By contrast, an aluminum can is infinitely recyclable, and can be used to make new aluminum cans over and over again.

It has been shown that the air inside homes is often more polluted than outdoor air. Maybe you...