The fluffy interiors of puffer jackets also need to be considered. A top ethical concern is the treatment of the birds whose down and feathers are used in jackets. Reports have emerged of geese and ducks being live-plucked for down and feathers.
Certifications such as the Responsible Down Standard and the Global Traceable Down Standard are a means by which companies can assure consumers that the down in their puffer jackets was ethically sourced, using the best practice of animal care.
Each standard ensures there are no live-plucking or force-feeding practices, and that the animals providing down and feathers are humanely treated according to the five freedoms of animal welfare.
However, buying an expensive coat does not automatically mean that a company has its house in order, just as buying cheaper "fast fashion" puffer jackets need not necessarily mean that the down is unethically sourced. Whatever the price of the jacket, check first whether the company has signed up to the Responsible Down Standard.
The main alternative to down is polyester filling, such as the recycled polyester ECOdown.
Unlike duck or goose down, ECOdown does not lose its insulating qualities when wet. The flip side is that polyester down is slightly heavier than duck or goose down. Brands that use ECOdown include Trenery and HoodLamb.
There are also other natural alternatives, such as batting made from merino wool, as used by Icebreaker, or the recycled goose down used by Patagonia.
Manufacturing processes
The long supply chains through which our garments arrive can mean that labour abuses continue to occur. The 2018 Ethical Fashion Guide was released last month so look at how local brands fare in terms of supply-chain transparency.
In April, Fashion Revolution Day aimed to connect and inform the public about the issues facing the estimated 60 million garment workers worldwide.
Well Made Clothes is a website that allows you to choose clothing that aligns with your values, be they environmental, social, ethical treatment of animals, or all three.
Coat care
The final choices are those you can make as a wearer. For the bundled-up commuter, choose a high-quality garment in a hard-wearing fabric in a classic style and it will last you many seasons (real seasons as well as fashion's artificial ones).
Again, fibre matters in longevity. Wool coats have a natural insulating quality. Acrylic, a synthetic substitute for wool, can develop pilling and does not have wool's natural advantages.
Selecting a brand that will repair your damaged coat ensures that you remain motivated to care for your garment. Finally, in terms of disposal, brands such as Kathmandu and H&M offer a take-back service at the end of the garment's life (although effective recycling of these garments remains a wicked problem for retailers). High-quality coats will always be in demand at op shops.
Why not wear what you wore last winter?
Retailers might not like this, but ask yourself whether you even need a fresh coat and, if so, whether it needs to be new.
The most environmentally friendly item is the one we already own. Increasing sales of second-hand clothing result in savings in carbon emissions, waste, and water usage per tonne of clothing.
Despite the supposed vagaries of fashion, winter coats are a great example of a garment that can last for many seasons if well cared for.
However, if you seek a winter wardrobe refresh, the enjoyment of rugging up in a new coat can be experienced at a lower cost economically and environmentally by buying second-hand, whether through eBay or op shops, or swapping or buying informally through friends in your social network.
Engaging in the sharing economy through clothing renting platforms such as Lana can allow you to rent a show-stopping coat for a special night out.
Given the many considerations involved in the choice of coat — be they workers' rights, cruelty to animals, or environmental impact — all we can do is make informed choices according to personal values.
For this reason, my first stop when doing some "sustainable shopping" will always be my existing wardrobe.