I’ve been enjoying Slate’s “Green Lantern” feed:
A 1992 study from Franklin Associates estimated that producing a year’s supply of disposables, which are composed largely of plastic, consumes roughly 6,900 megajoules of energy, vs. around 1,400 megajoules for a year’s supply of cloth diapers. Yet the study concluded that cloth ended up being 39 percent more energy-intensive overall, given the electricity needed to wash load after load of dirty diapers.
That conclusion is now woefully outdated, however, given the major advances that have occurred in washing-machine efficiency (PDF). For a washing machine made in 1985, an 11-pound load of cottons washed in warm water used up 1.68 kilowatt hours of electricity and 34 gallons of water; for a machine made two decades later, the relevant figures are just 0.95 kilowatt hours and 12 gallons.
A 2005 study (PDF) by Britain’s Environment Agency took into account some of these technological advances. In making their calculations regarding cloth diapers, the study’s authors used average energy-consumption figures for machines made in 1997. They concluded that there was “no significant difference” between the environmental impact of cloth and disposable diapers. Keeping a child clad in home-laundered cloth diapers for 2.5 years emitted 1,232 pounds of carbon dioxide equivalent, vs. 1,380 pounds for disposable diapers.
So there. Also, are Priuses actually worse for the environment than Hummers? (No: but the source of the urban myth is interesting.) And, are mechanical dishwashers bad for the planet? No they aren’t:
More than 100 Europeans were observed cleaning a dozen full place-settings by hand. The German researchers found that the average hand-washer is quite the wastrel, using 27.2 gallons of water, which requires 2.5 kWh of electricity to heat. (The most careless hand-washers were Spanish and Portuguese, while the most economical were German.) An ultra-efficient machine, by contrast, used only between 3.96 and 5.81 gallons of water, and between 1 and 2 kWh of electricity.Advantage, technology. But if you read the German study carefully, you’ll see that the best hand-washers came close to matching the machine’s performance.
The feed is here.
