Your Eco-Delemmas, Solved

Paper or plastic bags? Cloth or disposable diapers? Aluminum cans or glass bottles? If you want to go green but are baffled by such environmental quagmires, take heart: The eco-experts behind the green news and humor Web site Grist.org get to the bottom of these and other puzzles of the universe in their new book, Wake Up and Smell the Planet.

Read on, and watch the layer of fog start to lift away.

Excerpted from Wake Up and Smell the Planet by Grist.org, edited by Brangien Davis, © 2007 Skipstone.

Driving Speed: Is 55 the Magic Number?

Every single “Tips for Saving Gas” list tells you to drive 55 mph, but is that really the magic number? By many estimates it’s pretty darn close, though each vehicle has its own speed of maximum efficiency dependent on engines, car bodies and driving conditions. Gas mileage decreases rapidly at speeds above 60; boosting your highway speed from 55 to 75 can raise fuel consumption by as much as 20 percent. Driving at steady, reasonable speeds will save both gas and money.

Cans or Bottles?

The can versus bottle dilemma is a tricky one, but a good basic rule is to drink locally bottled beer in glass bottles if you can. Manufacturing aluminum is resource-intensive. Virgin glass beverage containers are also made from an abundant natural material: sand, mixed with limestone. The transformation of sand into glass is easier and less energy intensive than the laborious journey from bauxite to aluminum.

Leave the Computer in Sleep Mode, or Shut It Down?

There’s a nasty rumor persisting in the land of PCs: It purports that leaving your computer in sleep mode all night uses less energy than turning it on and off every morning and night. But it just isn’t true! At the end of the day, turn the thing off. Or even better, hit it with a sledgehammer, pack up your desk and go work on a vegetable farm.

Paper or Plastic?

The answer (drumroll, please): neither.
It’s generally understood that the plastic bag production process generates less water and air pollution and less solid waste than paper. In addition, the bags take up less space in landfills. Of course, paper bags trump plastic in the renewable resource realm, being made from trees rather than oil or gas, and being more commonly accepted in recycling programs. Also, paper bags are biodegradable and far less likely to disturb natural ecosystems.
In the end, the quantifiable difference between paper and plastic bags is minimal. The best option? To bring your own.

By Train, or by Car?

Travelers in the U.S. take 56 percent of our long-distance trip miles in a personal vehicle. Guess how much we travel long-distance by train? One percent.
Yet according to the Union of Concerned Scientists, the train is miles better. In terms of impact on global warming, air pollution, water pollution and habitat alteration, U.S. trains definitely come out ahead of planes and cars, with better ratings in all subcategories except common air pollution and land use.

Diapers: Cloth or Disposable?

In the grand scheme of things, the debate over the relative merits of cloth versus disposable diapers, like the one over paper versus plastic bags, tends to arouse passions out of proportion to its significance.
In 2005, the U.K Environmental Agency attempted to settle the question once and for all. The verdict? It doesn’t matter. No really, it doesn’t. Both manufacturers and parents could do more to reduce their ecological impact, but the choice between cloth and disposable is one of personal preference.

Microwaves or Ovens?

The good news is, despite popular parlance, microwaves are not nuclear—and in fact, like toaster ovens, they’re an efficient way to heat small portions (like lunch). The downside? Those mysterious spatters left inside by coworkers. Microwave ovens are more efficient than our familiar old friends, the electric and gas range/oven combos. They’re also faster and use electricity more efficiently (efficiency in this instance being a measure of energy going to the food versus energy wasted).

Turn off the Engine, or Idle?

The U.S. Environmental Protection Agency National Vehicle and Fuel Emissions Laboratory and the California Air Resources Board confirm that when given the choice of idling for a few minutes or turning your car off, you should always choose the latter.

Tests comparing emissions over minute-long increments for restarted versus idled cars confirm: Idling produces more emissions. Over nine minutes, an idling car will emit double the pollutants of a car that is turned off and then restarted.