This is a caring travellers conundrum which I feel represents a painful dilemma: Is it better to negatively affect certain living beings in the short term or the whole planet in the long term. In this case geese killed for their lightest insulating feathers; down, or more synthetic materials; plastic, in the world. Maybe by comparing how down is collected to the impact of the alternatives on the environment we can make an educated and sensitive decision.
But first lets make a comparison of the two in terms of their qualities and benefits in a finished sleeping bag. Down feathers are one of natures great moments, they are beautiful to look at and can simply hang in the air, they weigh so little we can not tell if we are holding one in our hand or not. They are so effective at insulating that no man made object can match it weight for weight. Each down feather is made up of many filaments which radiate from their central shaft, this creates loft which allows for air to be trapped and warmth kept in.
The alternatives to down are made from synthetic (man-made) materials mimicking natures design; polyester fibres set in wiggly single threads or fanned out designs. Some are better than others but nothing as yet matches down for insulation by weight or compression. Meaning that your sleeping bag can be lighter and smaller with down. But bear in mind that down can absorb a lot of water and is very slow at drying out, while polyester can dry out quickly.
A more detailed comparison, pitting natural down against its polymer imitators, can be found here (Source sierratradingpost.com/lp2/down-vs-synthetic-guide)
Where is down coming from?
In most cases down is plucked from geese killed for their meat, therefore down could be seen as a byproduct. Apparently some are plucked alive, (Source pleasebekind.com/clothes.html) which must be like having your hair pulled out, conversely it is possible to collect down from the ground or nest after it has naturally fallen off the bird.
About 65% of down is coming from Asia (Source downbuyingguide.com) where avian consumption is high, and animal living conditions are often poor. The rest are coming from Europe where “Fois Gras” and other ‘delicacies’ are made from geese and ducks by force feeding. So there is a fair degree of suffering in the donors life.
Yet the very highest quality down comes from mature birds in the wild who moult it naturally when the weather warms and it is collected from the ground or nests. The down from Eider geese in Norway is collected by this method, it’s more labour intensive and Eider down is more expensive partly for this reason. It is positive to see there is an “ahimsa” (non-violent) solution, because generally birds are killed around 4 months old.
A clarifying (over rationalising?) question might be “How many geese are needed to make a down sleeping bag?”
An approximate answer will be 8, although it is actually quite complicated to calculate exactly. Down is measured in “fill power” per weight, the fill power is higher for down that creates more loft, meaning it fills more space for its weight. Typically these range from 400-700 inches per ounce. Because down varies in “fill power” the number of geese needed to make the down sleeping bag also varies.
Wild Eider in Norway produce around 1.5oz (42g) per nest per year. (Source en.m.wikipedia.org/wiki/Down_feather) This is the highest quality down so a light weight filling would be possible. If your bag is taking 300g then it would take 8 birds. (8x42g=336g)
Presumable more weight of down will be collected from a dead bird or one plucked alive (which thankfully is outlawed and represents only 1% of all “harvested” down (Source en.m.wikipedia.org/wiki/Down_feather)). But the fill power from a young bird will be less and more weight will be needed, I’m guessing that this may balance out and 8 birds may still be enough but it could be many more.
So what should we do if we need a new sleeping bag; synthetic or down?
A synthetic bag generally will be heavier and larger when packed than a down bag of equivalent warmth, but maybe not by much if you use the latest technologies. If you get your bag wet you’ll be glad you bought a synthetic. Down bags usually cost more than synthetic.
From a practical perspective down is better unless you’re going to be in a wet climate.
If your bag is filled with regular down the geese will most likely have led a factory farming life and have been killed in the first few months of their existence. From the animal rights perspective down is an inexcusable abuse of an animals right to a free and natural existence.
A down bag will remain functional longer than a synthetic one, the plastic is more fragile than feathers, and the down once disposed of will return to nature quicker, while the polyester components will take thousands of years to break down fully. From an environmental perspective down is better; its components will return to nature easily. (Although the nylon shell of your bag will be blocking drains and filling the gills of a blue whale for millennia.)
A more ethical solution would be to ensure that the down filling your sleeping bag was collected from wild geese living a natural life, or a polyester filled bag made from recycled plastic. If you know of anyone manufacturing a sleeping bag to either of these ethical criteria let us know in the comments.
A down sleeping bag is the superior choice for most situations, being lighter smaller and warmer. It also has a lower impact on the environment as a whole. If you are able to live with knowing that the beings who grew the downy feathers that will keep you warm lived short torturous lives then it is a clear favourite. The alternative is to continue our addition of polymers to the world's ecosystems. This is continuing at a pace already and perhaps one more sleeping bag of polyester is negligible. What do you think?
I hope the exploration of this issue was informative and useful, feel free to leave comments, corrections and feelings below.