Though non-parents seem to regard changing diapers as the worst parental duty, new moms and dads quickly get used to the mechanics of a diaper freshening. One thing many of them never get used to: the gnawing guilt they feel throwing the diapers into a landfill. That guilt is not misplaced: Although experts quibble over whether cloth or disposable diapers have more of an impact on the environment, it’s clear that one of the downsides of disposables is that they linger long after they’re no longer doing their job.