[gmack]

Wait, they fly airplanes full of diapers to the West Coast!? I wonder what quantity of jet fuel exhaust gets spewed into the atmosphere, just so you can get diapers the next day. Even with the increased per-worker efficiency, is the overall environmental impact worse or better than cloth systems, or simply getting them from the corner store?

[ars]

Cloth diapers are worse for the environment compared to disposable, no matter how you get it.

(Disposable uses landfill space of which we have unlimited quantities, but cloth uses water which is in short supply. Also cloth uses more energy.)

But it's easy to tell if this method is better or worse for the environment: You have to pay for jet fuel, or truck fuel, or whatever. All forms of energy cost about the same. If it's cheaper to get it delivered via next day air, then it must have used less energy.

[pbhjpbhj]

See my other comment: http://news.ycombinator.com/item?id=1429494

Provided the nappies get re-used, you have a moderately good washing machine and don't tumble dry all the time then cloth are better - it's a very detailed study.

In addition if one has an A+ rated washer always line dries, reuses nappies for a second child (eg we bought ours 2nd hand on ebay and reused them and will sell them on or use them as clean-up cloths) then cloth nappies are substantially better.

>If it's cheaper to get it delivered via next day air, then it must have used less energy.

This appears to be specious reasoning. A company can charge more or less for delivery for competition purposes the actual cost of transportation is usually obscured. I can fly the 200mi to my in-laws more cheaply than taking the train, I don't believe it uses less energy to fly.

See for example http://www.seat61.com/CO2flights.htm which gives a figure of 90% CO2 saving by train (CO2 emission correlating with energy expense seems reasonable).

[ars]

If trains use 90% less energy, then why aren't they 90% cheaper? I mean the cost to run a train is almost entirely fuel, and the same is true for an airplane. (There is some staff, but it's about the same for both.)

So without even reading the study I'm already sure it's wrong.

And I found it - they assumed a load factor of 100% for trains, but 72% for airplanes. When actually in the real world airplanes are pretty full and trains are not - but they run them anyway. And trains will probably use more fuel if they were full, so their entire study is worthless.

(They do it a lot in the study - they use realistic or worse case number for planes and cars, but best case numbers for trains. And explain it by saying "This is how we can make the rail system better.")

Oh, and BTW the study they rely on doesn't say 90% anywhere. They just pulled that number out of thin air.

[pbhjpbhj]

>And I found it - they assumed a load factor of 100% for trains, but 72% for airplanes. When actually in the real world airplanes are pretty full and trains are not - but they run them anyway. And trains will probably use more fuel if they were full, so their entire study is worthless.

Fair enough, I can't be bothered to check your analysis, just like I cherry picked the citation. However assuming that the trains are full and aeroplanes aren't isn't really a problem here. Most long distance trains I've been on here are standing room only (except in 1st class). I've been on a few half full flights though most of the budget airlines are pretty good at getting full capacity.

There is a lot of competition in internal flight routes here but none on train routes. Train routes are monopolies. They do very strange things with train pricing - sometimes my MiL can get to us cheaper (via London, about 750km as the crow flies, 1 ticket) than we can visit the next town (about 20km, 4 tickets). Flights are priced using a scarcity model that makes early bookings almost the same as the taxes and later bookings as much as traditionally priced airlines.

[btilly]

If it's cheaper to get it delivered via next day air, then it must have used less energy.

Big if. No shipper ever reveals their true costs to you, they always build in some margin. An amusing illustration of this is UPS. Internally 2-day shipping costs more than overnight (they have to pay for warehouse space to keep the packages around for a day), but they charge more for 1-day.

In the case of Diapers.com, no option is provided to let you get any other kind of shipment speed. That's because they see their competition as regular retail stores. And the cost savings of eliminating the retailer are enough that they can justify much higher shipping costs.

For a realistic comparison see http://en.wikipedia.org/wiki/Fuel_efficiency_in_transportati... (and keep in mind that the true costs for transporting stuff by aircraft can depend more on volume than weight).

[xal]

Do you have some more information on this? Our first will arrive within the next 2 weeks and this sounds really interesting.

[ars]

Oh, this is a massive debate, and more emotional than rational. "But cloth should be better! It just seems like it should be better!"

Wikipedia is probably as good an introduction as any: http://en.wikipedia.org/wiki/Cloth_diaper#Debate

Also, cloth diapers cause more rashes. (Unless there is an allergy to the disposable one, in which case it causes more.)

[pbhjpbhj]

>cloth diapers cause more rashes.

I'd heard the contrary (we use both cloth and compostable disposables), any citations?

I can see how those using strong washing detergents could have problems, we use ecover and haven't had nappy rash problems (anecdotal I know).

[ars]

Yes, here: http://emedicine.medscape.com/article/801222-overview

[asmosoinio]

This British study calls it roughly a break-even, mostly depending on the energy spent on drying the diapers.

http://publications.environment-agency.gov.uk/pdf/SCHO0808BO...

[pbhjpbhj]

From http://publications.environment-agency.gov.uk/pdf/SCHO0808BO...

>The average 2006 disposable nappy would result in a global warming impact of approximately 550kg of carbon dioxide equivalents used over the two and a half years a child is typically in nappies. The global warming impact from disposable nappies use has decreased since the previous study due to manufacturing changes and a 13.5 per cent reduction in the weight of nappies.

and then for cloth nappies

>For reusable nappies, the baseline scenario based on average washer and drier use produced a global warming impact of approximately 570kg of carbon dioxide equivalents. However, the study showed that the impacts for reusable nappies are highly dependent on the way they are laundered. Washing the nappies in fuller loads or line-drying them outdoors all the time (ignoring UK climatic conditions for the purposes of illustration) was found to reduce this figure by 16 per cent. Combining three of the beneficial scenarios (washing nappies in a fuller load, outdoor line drying all of the time, and reusing nappies on a second child) would lower the global warming impact by 40 per cent from the baseline scenario, or some 200kg of carbon dioxide equivalents over the two and a half years, equal to driving a car approximately 1,000 km.

FWIW we buy compostable disposables to limit landfill impact (contrary to another comment landfill area is not infinite) and bought our "real" nappies on ebay and have then reused them. We don't tumble dry nappies (UK) and practice what's considered early potty training which reduces cleaning requirements¹.

---

¹Clearly reducing nappy changing as much as possible and reducing the period of nappy wearing has a great impact.

[ars]

Why focus just on global warming? Water shortage is a far far far larger problem. I know it's not you, but this obsession with global warming is horrible. There are far worse problems.

And landfill space is infinite. The earth is enormous. There are just political objections to landfills so they keep them in short supply. For example you could fill old coal mines with landfill and never run out of space. You could undo mountaintop removal by filling it with dilute garbage, then a deep layer of topsoil.

There really is an infinite amount of space - we can't make more garbage than there is matter on the earth. So whatever material we make, we automatically have room to bury it.

[pbhjpbhj]

The linked analysis is really good and considers water usage. Water is also used to create disposable nappies as well as irrigating cotton plantations.

>And landfill space is infinite. The earth is enormous.

Landfill pollutes, run-off kills wildlife and poisons water supplies. Methane produced, as well as other decomposition gases (eg mercury bearing or radioactive gases) makes close habitation a problem. Of course methane is currently related to adverse global climate change and landfill is one (if not the?) largest source of human-produced methane.

Topsoil is certainly not limitless either, good topsoil is costly; it takes time and a proper mix of organic matter to make. You can hide your non-degradable plastics and heavy metal contaminant laced electronics under as big a heap of topsoil as you like, they're not going to magically turn into soil nutrients.

[melling]

Sorry, the futuristic rail system will arrive a little later. Two steps forward, one step back. Right-sizing the boxes goes a long way towards using extra capacity. If you don't need them the next day, is shipping them in tractor trailers that much better?

[potatolicious]

> "is shipping them in tractor trailers that much better?"

Also, having the product carried the entire way in bulk, large-scale transport filled to the brim seems a might more efficient than little single-occupancy vehicles all converging on a retailer miles from their own homes.

I suspect we'd all save a lot of fuel if somehow all products were delivered to the home instead of forcing cars and SUVs onto the road to retrieve them piecemeal.

[noonespecial]

That's a really good point. UPS is relentless when it comes to route planning and fuel saving. They don't even make left turns.

I've seen old women visit 5 different grocery stores in a day to save a few cents with coupons at each.

[shard]

The lowest-environmental-impact choice is obviously no diaper at all: http://diaperfreebaby.org/

[pbhjpbhj]

It may be, but it's not obvious. For example you may have to clean a lot more clothing and effects than with a diapered baby that is being taught EC. If diapers were used for a brief time they'd be reusable for many more children and thus have a lower impact per user.

I'm not disagreeing just that these analyses are always extremely complex.

[chadmalik]

yeah the fact that the singularity guys are trumpeting this socially useless "innovation" is hilarious. gee now i get my online diaper order shipped next day! woo hoo!