GOD GAVE US LANDFILLS FOR A REASON:

Despite decades of exhortations and mandates, it's still typically more expensive for municipalities to recycle household waste than to send it to a landfill. Prices for recyclable materials have plummeted because of lower oil prices and reduced demand for them overseas. The slump has forced some recycling companies to shut plants and cancel plans for new technologies. The mood is so gloomy that one industry veteran tried to cheer up her colleagues this summer with an article in a trade journal titled, "Recycling Is Not Dead!"

While politicians set higher and higher goals, the national rate of recycling has stagnated in recent years. Yes, it's popular in affluent neighborhoods like Park Slope in Brooklyn and in cities like San Francisco, but residents of the Bronx and Houston don't have the same fervor for sorting garbage in their spare time.

The future for recycling looks even worse. As cities move beyond recycling paper and metals, and into glass, food scraps and assorted plastics, the costs rise sharply while the environmental benefits decline and sometimes vanish. "If you believe recycling is good for the planet and that we need to do more of it, then there's a crisis to confront," says David P. Steiner, the chief executive officer of Waste Management, the largest recycler of household trash in the United States. "Trying to turn garbage into gold costs a lot more than expected. We need to ask ourselves: What is the goal here?"

Recycling has been relentlessly promoted as a goal in and of itself: an unalloyed public good and private virtue that is indoctrinated in students from kindergarten through college. As a result, otherwise well-informed and educated people have no idea of the relative costs and benefits.

They probably don't know, for instance, that to reduce carbon emissions, you'll accomplish a lot more by sorting paper and aluminum cans than by worrying about yogurt containers and half-eaten slices of pizza. Most people also assume that recycling plastic bottles must be doing lots for the planet. They've been encouraged by the Environmental Protection Agency, which assures the public that recycling plastic results in less carbon being released into the atmosphere.

But how much difference does it make? Here's some perspective: To offset the greenhouse impact of one passenger's round-trip flight between New York and London, you'd have to recycle roughly 40,000 plastic bottles, assuming you fly coach. If you sit in business- or first-class, where each passenger takes up more space, it could be more like 100,000.

Even those statistics might be misleading. New York and other cities instruct people to rinse the bottles before putting them in the recycling bin, but the E.P.A.'s life-cycle calculation doesn't take that water into account. That single omission can make a big difference, according to Chris Goodall, the author of "How to Live a Low-Carbon Life." Mr. Goodall calculates that if you wash plastic in water that was heated by coal-derived electricity, then the net effect of your recycling could be more carbon in the atmosphere.

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