Wanna buy a car that’s gentle on the environment? Then don’t buy a new hybrid. Are you buying organic food because it’s good for the environment? If so, you’re making a mistake.

Those are just two of the 10 claims made by the writers at “Wired” magazine in its lead story: “Inconvenient Truths: Get Ready to Rethink What it Means to be Green.” Using facts, fresh insight and airtight logic, they challenge 10 popular assumptions about green living and suggest better alternatives.

One guarantee: whether you’re a tree hugging environmentalist or a cigar chomping Hummer driver, you’ll be surprised.

Do you want to live in America’s “greenest” city? Then head to Manhattan. According to Wired’s Matt Power, “A Manhattanite’s carbon footprint is 30 percent smaller than the average American’s.” Most residents work there, nearly two-thirds walk, bike or take public transit to work. They also live in tall apartment buildings that are more efficient to heat and cool. And no one has a lawn, which means no lawnmowers that emit 11 cars worth of pollution per hour.

Are air conditioners bad for the planet? Actually, they’re more environmentally friendly than heaters.

If a snowbird in Palm Desert wants his home to be 70 degrees and it’s 100 outside, the air conditioner has to change the temperature by 30 degrees. If he stayed home in Boston, where it’s 10 degrees, his heater would have to change the temperature by 60 degrees. His old home emitted 14 times more carbon dioxide than his air conditioned place out west.

How much better for the planet is organic food than chemically treated food? It’s not. Organic food leaves a deeper carbon footprint. Let’s start with milk. Writer Joanna Pearlstein points out that it takes 25 organic cows to make as much milk as 23 conventionally raised cattle. Reason? Organic cows aren’t beefed up (sorry, bad pun) with hormones. Organic cows also generate 16 percent more greenhouse gases than their counterparts.

Ditto for beef, because organic steers take longer to get bigger, which means they spend more time polluting. What about grass-fed beef? They create nearly twice the methane as a cow on a grain diet. That’s something they don’t tell you at Whole Foods.

Finally, fruits and vegetables. Natural fertilizers deliver lower than average crop yields, which require more land. And organically grown strawberries trucked here from California or Mexico leave a far deeper carbon footprint than local produce grown with pesticides.

Will preserving old growth forests help reduce warming? No. Old growth trees actually contribute to warming.

It’s all about the math. A tree breathes in, so to speak, about 1,500 pounds of CO2 in its first 55 years. Then it takes in lesser amounts until it eventually burns or rots out, which is inevitable. When that happens, all that CO2 gets released.

Forests are famous for being natural air fresheners, but some Canadian forests actually release more carbon than oxygen because of all these decomposing old growth trees. So if your goal is to diminish the carbon footprint of trees, Wired suggests cutting down old, decaying trees and planting lots of new ones.

Finally, if you want to buy a car that’s good for the environment, what’s better than a hybrid?

A used car. Making a new Prius requires 113 million BTUs (British Thermal Units, a standard energy measurement). A used car already is made, so its “carbon debt” already paid. Wired suggests that if you buy a 10-year old Tercel, which gets 35 mpg, a Prius will have to drive 100,000 miles before it starts leaving a smaller carbon footprint. This explains the enthusiasm people suddenly have for the old 49-horsepower Geo Metros.

What Wired has done is point out that living green is not the same as feeling green. The gap between the two is surprisingly wide.

John Carlson hosts a daily radio program with KOMO 4’s Ken Schram each weekday at 9 AM on AM 570 KVI. He also broadcasts daily radio commentary on KOMO 1000 news. E-mail him at jcarlson@fisherradio.com or johncarlson@komoradio.com

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