Several years ago, the UK Environment Agency published a paper examining the lifecycle impacts of disposables and cloth diapers, as used by children for the first couple years of life. At that time (2008), their analysis concluded that cloth could make less impact than disposables. Their analysis hinged, however, on the washing and drying choices made by the cloth users. Those that washed with 60 degree Celsius water instead of 90 and line-dried instead of using a clothes dryer made considerably less impact. Those that made all the wrong choices, though, drove cloth to a point where it was worse than disposables.
The trick, though, is choosing which thing you're going to focus on. Their study (as any European study of that time would) focused largely on CO2 emissions. It's not a bad standpoint, really, as it probably best captures the impact of the manufacturing and transportation phases. It captures the energy usage by cloth users to clean the diapers.
Despite their efforts to clarify the disparate impacts of both types, it becomes increasingly difficult to compare. Cloth diapers don't really go to landfill, as they wind up becoming rags and things after they've served their duty as diapers. But, cloth diapers use way more water than do disposables. Disposables use way more petroleum because of transportation and the fact that they're made from plastic (which is petroleum based).
The point of all this? I think it's good to question one's impact on society and the world around them. I think it's also important to realize that there aren't often clear-cut answers. I posted similar analysis to this here a couple of years ago, but I'll give it another go. Consider:
I live in a house built in 1940, in which the original plumbing fixtures are in fine functional condition. This means five U.S. gallons of water get used every time someone flushes a toilet in this house. Conversely, we have newer high-efficiency laundry machines. I can't find exact numbers for our model washer, but the
California Energy Commission says newer models use 14-27 gallons of water. For conversation and easy math, I'll say ours uses 20 gallons per wash. I think I'd be fair in suggesting the average person uses a toilet about five times per day-once in the morning, once after breakfast, once after lunch, once after dinner, and once before bed.
In my (admittedly anomalous) house, toilet usage per hypothetical person would amount to 25 gallons of water per day. We all know many diapers can hold more than one go. Supposing disposables, that's 25 gallons of water not going down the drain. Supposing cloth diapers, let's say three per day in total, and that one can wash about three days' worth in one cycle. So, instead of 75 gallons of water, we're now talking about 20 gallons of water. Even supposing brand new fixtures, we're still not talking about much difference. A new high-efficiency toilet can use as little as 1.2 gallons per flush. Times five flushes, that's six gallons per day, 18 gallons per three days. That compares to our 20 gallons to wash the cloth diapers.
So like I say, it's not really all that clear cut in the end. Do you worry about filling the landfills? Do you worry about water usage? Do you worry about petroleum usage? Depending upon how you answer these choices, you as a diaper user can tailor your choices to match your ethical concerns. At least, you can make informed choices when you do decide to indulge.