LEATHER INDUSTRY DATA SHOWS US IT IS FAR MORE IMPACTFUL THAN EVEN SYNTHETIC ALTERNATIVES.
The Leather Panel has shared a study that begins counting emissions after the slaughterhouse section of the leather supply chain. Included emissions here are energy use in tanneries, chemical outputs and their emissions, transportation, and so on. In this case, CO2e emissions (emissions of various gasses translated to the common unit of carbon) for leather equal 17.0kg of CO2e per square meter of leather produced.
In comparison, artificial leather’s total supply chain has an impact of 15.8kg of CO2e per square meter. As you can see, even allowing the leather industry's unreasonable assumption of no impact from animal farming, faux leather's entire life cycle produces fewer emissions.
Leather Panel’s shared study chooses to include end-of-life incineration in the impact of faux leather. It’s illogical to include incineration for synthetics but not for animal leather, and while faux leather won’t effectively biodegrade, neither will animal derived leather to the point of total decomposition – even in controlled climate study conditions shared by leather tannery groups. In an accurate comparison, synthetic leather would have even less emissions than cow skin leather.
Elsewhere in their report, the Leather Panel shares an impact estimate which includes farm emissions – this is a fairer estimate of leather’s impact, and again comes from their own reporting. Here, the carbon footprint of cow skin leather is found to be 110.0kg of CO2e per square metre, making cow skin leather nearly 7 times more climate impactful than synthetic leather by the square metre.
THE CARBON COST OF OUR LEATHER JACKETS, SHOES AND BAGS
So how many kilograms of CO2e are in our leather jackets, bags, and shoes?
After asking creators of these products how much leather is required for them, we have all the numbers we need to work this out.
By multiplying the CO2e/m2 emissions of both faux and cow skin leather respectively, with the material requirements for each product, we see exactly how our fashion choices contribute to the climate crisis.
If you’re someone who has heard that vegan leather is worse for the environment, or if you’re interested in the ongoing safety of the ecological world, these calculations may be worth your consideration when next designing or buying these goods.
All calculations on this page have been verified by Faunalytics.
Bag leather requirements from e-mail correspondence with Sans Beast (0.914m2), shoe leather requirements averaged from data from Russell Moccasin Co, as well as Willy Moc Handcrafted Shoes (boots 5-8sq ft, shoes 3-5 sq ft, averaged and converted to m2), jacket leather requirements based on e-mail correspondence with Moore & Giles Inc (10-15sq ft, averaged and converted to m2).
“Would you rather the skins were just tossed into landfill?”
Based on the data, our answer is yes, and here’s why: throwing a cow hide in the garbage has a smaller climate impact than turning it into leather.
Yes, the carbon that is biologically stored in untanned cow hides if sent to landfill would produce some methane emissions as they rotted, but it’s nowhere near as much CO2e created when we chemically transform those skins into leather (which will eventually be discarded or incinerated anyway).
This holds true even when we factor in the footprint of a synthetic alternative assuming someone may opt for that instead.
In fact, just the processing and tanning of raw skins into leather is about as impactful as producing faux leather itself.
For the sustainable fashion community that is rightfully concerned with waste, this is quite counterintuitive. Why we should throw something away instead of using it is a tough sell.
Scroll down for our calculations.
*DATA FOR LANDFILL EQUATIONS
Is the impact of sending hides to landfill worse or better than the impact of using hides to turn them into leather? (Sources below)
Total emissions from sending unprocessed hides to landfill (in kg of CO2e / m2 of hide)
= Total emissions from turning hides into leather – Emissions from leather processing + Emissions in landfill
= 110 – 17 + 1.152
= 94.152 kg of CO2e / m2 of unprocessed hide in landfill
Total emissions from turning hides into leather = 110kg of CO2e / m2 (Source: Leather Panel)
Difference in emissions (i.e., leather – landfill)
= Total emissions from turning hides into leather – Total emissions from sending unprocessed hides to landfill
= 110 - 94.152
= 15.848 kg of CO2e / m2
Additional sources and calculations:
Emissions from leather processing = 17kg of CO2e / m2 (Source: Leather Panel)
Emissions in landfill
= CO2 emissions per square metre of hide x methane-carbon mass ratio
=CO2 per tonne of hideHides per tonne Hides per square metreMethane-carbon mass ratio
= 624163.93 14.411612
= 1.152 kg of CO2e / m2
CO2 per tonne of hide in landfill
624kg of CO2 is emitted per tonne 1000 kg of putrefied hides (Source: Leather Panel).
Hides per tonne
An average cow hide weighs 6.1kg (Source: UNESCO).
1000 / 6.1 = 163.93 hides per tonne.
Hides per square metre
An average cow hide is 47.5 square feet or 4.41 square metres (Source: Leather Hide Store)
= 1 hide per 4.41 square metres
Methane-carbon mass ratio
In order to turn data which refers only to carbon into data which is aligned with the rest of our data -- measured in CO2 equivalent emissions -- we need to account for how carbon would turn into methane in the process of breaking down in landfill (Source: U.S. Environmental Protection Agency). Methane and carbon have different atomic masses, 16 and 12 respectively (Source: National Library of Medicine: Methane; Carbon).
Verified by Faunalytics, calculated by Emma Hakansson, and written by Joshua Katcher and Emma Hakansson