The Stanly News and Press (Albemarle, NC)

Community News Network

December 10, 2013

Old-fashioned trimming for tree isn't as green as you might think

Strands of lights are ubiquitous this time of year - tangled in leafless trees, framing windows, sparkling their way to Santa's sled. They are a beaming reminder of both the warm feelings of the holiday season and the environmental costs of this time of hyper-consumption. In 2003, a paper published by the Department of Energy estimated that holiday lights accounted for 2.22 terawatt-hours of energy use per year in the United States, which roughly equals the energy consumed by 200,000 homes annually. With numbers like that, coal may be the best thing to stuff in your neighbor's twinkling stocking. He may need it.

Fortunately, Christmas lights have gradually switched over to LED in recent years. They are up to 90 percent more efficient than old-fashioned incandescent bulbs. So, should you trash your old holiday blinkers for their LED counterpart?

From an environmental perspective, it's rarely advisable to discard something that works and replace it with an energy-efficient version, since the energy required to produce your new bauble is often greater than the savings it offers once you use it. It wouldn't make sense, for example, to trash a perfectly good sedan to buy a new Toyota Prius: Producing a car takes a lot of energy, and hybrids are only about twice as energy-efficient as conventional engines.

Holiday lights, however, are an exception to the rule. A new strand of LEDs will last four or five decades, possibly the rest of your life, depending on how long you leave them on (and how long you live). They're also less likely to start a fire, which is important when you're wrapping them around a bundle of kindling like a Christmas tree. If you're still harboring an old strand of incandescent lights, the Earth begs you to ditch it and go for the LEDs. (If it's one of those multicolored, flashing strands, your neighbors would probably second the motion.)

Of course, there are more extreme options for electricity grinches. When I was a child, my favorite tree adornment was a string of popcorn. Making such a thread is a fun family activity, and you can sneak a few kernels for yourself in the process.

Is it greener than a strand of lights, though? To make this comparison, we'll have to make some assumptions.

It's hard to say how much embedded energy is in a strand of Christmas lights. However, since the lights will last 40 or 50 years, that embedded energy comes very close to zero on a yearly average. The only energy we have to attribute to the lights is the electricity, which, for a strand of larger LEDs, is 2.5 watts. If you run them four hours per day for 30 days, that means 0.3 kilowatt-hours over the course of a season. According to EPA conversion data, generating that much electricity would emit 0.44 pounds of greenhouse gas equivalents. (A carbon dioxide equivalent is all the greenhouse gases emitted, expressed in terms of the global warming potential of carbon dioxide.)

Now for the popcorn. There's very little popcorn-specific environmental data, but the variety of corn commonly grown for popping is closely related to the corn used in cornmeal. So if we just use generic corn data, our estimates will be close enough.

According to researchers at the University of Massachusetts, cultivating an acre of corn generates approximately 1,700 pounds of greenhouse gas emissions. The average farm produces 155 bushels of corn per acre. Since a bushel of shelled corn weighs approximately 56 pounds, there are around 0.2 pounds of greenhouse gas equivalents embedded in a pound of corn by the time it leaves the farm gate. For most foods, transporting, processing and cooking account for slightly more than the amount of greenhouse gas emitted during cultivation and harvest. So let's say a pound of popcorn - which is probably enough to trim a medium-size tree - would result in the production of just under a half-pound of carbon dioxide equivalents.

In other words, from an environmental perspective, there's very little difference between trimming your tree with a pound of popcorn and using a strand of LED lights. That may seem surprising, since natural, farm-raised popcorn just feels greener than manufactured lights.

But details make a difference. Old-fashioned incandescent lights would be far, far worse for the environment: They use 10 times as much electricity as LEDs and don't last nearly as long. You'll also need to store your LEDs properly and turn them off when no one will see them anyway. Of course, if you have a few extra lights, you can't eat the leftovers.

 

1
Text Only
Community News Network
  • Why do wolves howl?

    Of all the myths that dog the wolf, none is more widely accepted than the idea that wolves howl at the moon. Images of wolves with their heads upturned, singing at the night sky, are as unquestioned as a goldfish's three-second memory or a dog's color-blindness (both also myths).

    April 18, 2014

  • Biggest student loan profits come from grad students

    This week, the Congressional Budget Office projected that the federal government would earn roughly $127 billion from student lending during the next 10 years.

    April 18, 2014

  • quake.jpg Pennsylvania won’t take action following Ohio ruling on quakes, fracking

    Pennsylvania officials plan no action despite new Ohio rules on drilling that affect a seismically active area near the state line.

    April 18, 2014 1 Photo

  • Raw oysters spike U.S. rise in bacterial infections, CDC reports

    Raw oysters, so good with hot sauce, increasingly can carry something even more unsettling to the stomach: A bacteria linked to vomiting, diarrhea and pain.

    April 17, 2014

  • To sleep well, you may need to adjust what you eat and when

    Sleep.  Oh, to sleep.  A good night's sleep is often a struggle for more than half of American adults.  And for occasional insomnia, there are good reasons to avoid using medications, whether over-the-counter or prescription.

    April 16, 2014

  • Doctors to rate cost effectiveness of expensive cancer drugs

    The world's largest organization of cancer doctors plans to rate the cost effectiveness of expensive oncology drugs, and will urge physicians to use the ratings to discuss the costs with their patients.

    April 16, 2014

  • Allergies are the real midlife crisis

    One of the biggest mysteries is why the disease comes and goes, and then comes and goes again. People tend to experience intense allergies between the ages of 5 and 16, then get a couple of decades off before the symptoms return in the 30s, only to diminish around retirement age.

    April 15, 2014

  • treadmill-very-fast.jpg Tax deduction for a gym membership?

    April marks another tax season when millions of Americans will deduct expenses related to home ownership, children and education from their annual tax bill. These deductions exist because of their perceived value to society; they encourage behaviors that keep the wheels of the economy turning. So why shouldn't the tax code be revised to reward preventive health?

    April 15, 2014 1 Photo

  • Google acquires drone maker Titan Aerospace to spread Internet

    Google is adding drones to its fleets of robots and driverless cars.
    The Internet search company said it acquired Titan Aerospace, the maker of high-altitude, solar-powered satellites that provides customer access to data services around the world. Terms of the deal weren't disclosed.

    April 14, 2014

  • 25801486.jpg VIDEO: Northern California bus crash kills 10

    At least nine people died in Northern California on Thursday night, in an accident involving a bus, a car and FedEx truck. The bus was filled with high school students from Southern California who were on their way to visit a college campus.

    April 11, 2014 1 Photo

Graduation Salutes
Seasonal Content