A new lifecycle assessment report from Sørensen Leather shows that the environmental impact of leather is extremely small if the calculations take into account the material’s durability.

Like many companies producing and supplying leather now, Sørensen Leather has been on the receiving end of loud encouragement from its customers to provide information about the carbon footprint of its materials.

The Denmark-based company, which sources finished leather from trusted partners but runs no tanneries of its own, accepted that it would be of benefit to everyone in its supply chain to put the necessary information together for a comprehensive lifecycle assessment (LCA) of its products. This has taken 18 months of painstaking work, but the results are in and they are deserving of very close attention by everyone in the leather industry.

The industry has argued for years that leather’s durability is one of its greatest attributes, that its longevity is something to love and be proud of, especially because leather often only becomes more beautiful with age. Leather products are eminently repairable. The length of time a mended product can remain in use makes the cost and effort of carrying out repairs worthwhile. Each of these are pivotal qualities for materials, products, companies and entire industries to be able rightfully to claim a place at the circular-economy table.

Now, thanks to Sørensen Leather’s new LCA, the industry has figures that show how big a role product longevity can play in lowering carbon footprint calculations.

Long view

Eighteen months’ work may seem a lot, but Sørensen Leather takes the long view of things. Last year, the company celebrated its fiftieth anniversary, marking the half century since founder, Arne Sørensen, set it up (in the garage at his family home in Egå, near Aarhus). “He was 25 years old when he started out,” explains current chief executive, Louise Vesterskov Sørensen, the founder’s daughter. She joined the company in 2006, as her brother, Mads, had done five years earlier; she and her brother now run it together.

“My father was in the furniture business, selling wheels for chairs. He spent a lot of time in furniture factories listening to his customers talk about leather,” Ms Vesterskov Sørensen explains. “When he decided to start out on his own, he became a representative for two tanneries.” The company built up its business from there and soon moved to bigger premises so that it could add to the leather collections it was sourcing and offer an increasingly flexible service to customers. Its headquarters are now in Lystrup; the facility there stores around 20,000 hides in more than 450 colours. Furniture and interior design still make up its biggest, but not its only market segment.

Easy stories

This flexibility and a commitment to high-quality leather have coincided with several important changes in the market. When a large percentage of leather production in the Nordic countries moved away, some buyers began to base their purchasing decisions on Excel spreadsheet data, or were often won over by what Louise Sørensen refers to as “easy stories”. The Sørensens began to think deeply about how they could best present their collections in this environment.

Efforts to visualise the good work of the company’s partner tanneries, of which there are around ten, and the high quality of the leather they produce have led to new ways of presenting the leather, including new ways of photographing it.

“Something else that has happened is that we have also begun to work much more closely with architects and designers,” she continues. “We want to inspire them and work with them at a strategic level. Now we develop collections with them as well as with the tanners.” The Danish company has known these leather manufacturers for many years and is aware of the strengths of each. From this, it knows which supplier to work with if a project requires, aniline leather, for example, and which to choose if veg-tanned leather will work better in another job. 

Customers working on these projects often have limited familiarity with how different types of leather work, with what is feasible and what is not. They are, benefitting from the expertise of their specialist leather supplier and its connections to the tanners. And this same set of relationships has also been of help in the more recent quest of gathering accurate information about carbon footprint. “More and more questions about this began to come up three or four years ago,” Ms Sørensen says. “Our customers were used to new buildings needing to have CO₂ emissions documentation, but this was happening for building interiors as well; demand was coming there too. Architects wanted to have information and documentation about the materials in use in the interior, especially in publicly funded buildings.”

Calculation tools

She explains that there are popular tools for calculating CO₂ emissions from wood, foam and other materials already. However it seemed clear to the Sørensen Leather team that some of these tools were calculating leather’s contribution to emissions inaccurately. “We simply couldn’t understand how a piece of leather could add so much to the emissions figure,” the chief executive recalls, “but our customers were finding it difficult to refute claims that leather was increasing the overall carbon footprint by too much and that it would be better to use fabric instead.”

In preparing to respond to this, she says she and her brother realised quickly that embarking on their own LCA would be worthwhile. “Facts and data are stronger arguments than thoughts and feelings,” she points out. She admits it was hard work and that it took longer than the leadership team at the company expected, but the partner it worked with, specialist consultancy EnergySolution, offered lots of help and encouragement.

EnergySolution insisted on working with as much primary data as possible. In this case, the tannery partners are in various countries and collect data in different ways. Gathering consistent data that the consultancy could input accurately and fairly into the LCA report it was compiling proved impossible. “There were meetings, conversations with different people about this and a lot of back-and-forth,” Louise Sørensen confirms. The solution was to estimate this component using the most recent Product Environmental Footprint Category Rules (PEFCR) for finished leather and leathergoods. She describes working with the team at EnergySolution, which is also based in Denmark, as a good match, explaining: “We needed experts around us who knew how to conduct an LCA; EnergySolution knows.” It conducted the analysis for the leather company in accordance with ISO standard 14067:2018 and submitted the results for verification by an independent third-party specialist.

The results are in

A headline finding from the report itself is that Sørensen can attribute emissions of 8.7 kilos of CO₂-equivalent (CO₂e) to each square-metre of finished leather that it brings to market. What happens in the upstream raw material supply chain counts for 1.6% of the total and EnergySolution included data for water, energy, chemicals and packaging when working the total out. In fact, its figures are for 1.1 square-metres of leather, calculating that 0.1 square-metres would go to waste.

“That was what the consultants insisted on,” Louise Sørensen explains, “but it shows that the 8.7 figure could easily have been less.” The point is that the specialists permitted no short-cuts. Acknowledging what it calls “the constraints of direct comparisons arising from differences in calculation methodologies”, the LCA report says this figure, an average across all of the company’s leather collections, is in line with the emissions from 790 grammes of chocolate, 1.1 kilos of coffee beans, or a 61-kilometre drive in a new diesel car.

A particularly interesting focus of the Sørensen LCA is that it also examines what the long lifespan of leather means for its carbon footprint, leading to the conclusion that its durability means the emissions calculation for leather reduces significantly over time. With the 8.7 kilos of CO₂e per square-metre of finished leather as a starting point, the study went on to calculate that using leather in a chair or sofa or as part of the interior design of a building for five years will bring the emissions calculation for the leather down to 1.7 kilos of CO₂e per square-metre. After 10 years of use, this figure will come down further to 0.87 kilos and if the leather in the product stays in use for 25 years, its carbon footprint will be 0.35 kilos of CO₂e per square-metre.

Smell the coffee

This means that any customer using leather from Sørensen in a sofa, for instance, will be able to calculate the carbon footprint of that leather as 8.7 kilos of CO₂e if it uses the sofa for one day. But if the sofa stays in use for 25 years, the figure will be 0.35 kilos of CO₂e per square-metre. This is a reduction of more than 95%. Continuing with the coffee comparison, emissions from this leather would then equate to the emissions figure for 55 grammes, or enough coffee beans for a party of four people to have one double espresso each after a lunch.

Carefully constructed pieces of furniture with leather upholstery can easily stay in use for considerably more than 25 years. A Financial Times feature in early 2024 compiled comments on furniture from previous interviews with influential people across the world of business, fashion, design and architecture sharing details of their favourite sofas and chairs.

Those declaring a love for leather upholstery included Mandy Madden Kelley, founder of Pagerie, a high-end accessories brand for pets, who chose a 1960s Erik Jørgensen Ox Chair by Danish designer Hans J Wegner (whose furniture ideas, like those of a number of influential twentieth-century designers from Denmark, are still in production and frequently use Sørensen Leather). Architect Frida Escobedo said she had long coveted, and recently acquired, a Knoll Brigadier leather sofa also created in the 1960s by Italian designer Cini Boeri.

Japanese clothing and footwear designer Hiroki Nakamura also declared his love of leather furniture, especially for two club chairs, probably from the 1930s, that he found at a flea market at Clignancourt in Paris and had them shipped all the way to his home in Tokyo. He told the FT that he loved the chairs because they still had their original cognac-coloured leather upholstery, albeit with many scuffs and cracks. “They are kind of worn out,” he told the newspaper, “but I like how they look.” 

For generations

Sørensen Leather has pledged to continue working on its LCA and to keep its numbers up to date. The chief executive has also said she will seek to meet with other specialist consultancies and ask them to take these new numbers for leather on board and apply them to their carbon footprint calculations. She explains: “Our thought was to make this a part of our competition with other materials. Longevity proves that leather’s environmental impact, if it is higher in the beginning, is much lower than that of other materials over 10 years or 25 years. Buyers should choose something that will last for generations.”

She says early reactions from customers show that they are happy with the findings of this LCA. She adds that many of them “knew instinctively that leather is a great material”. She is glad to have been able to share with them “the facts that prove it”. The message that must spread is that, just as leather is beautiful and only grows more beautiful over time, its carbon footprint is low and becomes lower with every year it stays in use.

A final point emerges from Louise Vesterskov Sørensen’s comment about architects being especially keen on accurate information regarding materials’ carbon footprint if the building they are working on is publicly funded. The European Commission has said that it wants to integrate circular-economy principles into public procurement in the European Union. Communications about this consistently point to a time in the near future when it will only be permissible to spend public money on materials that are in keeping with the circular economy. We have argued in this section of World Leather since 2020 that leather is the circular-economy material par excellence. Leather deserves to be among the top options when public buildings are being fitted out or refurbished. Longevity’s huge influence on achieving low carbon footprint over time can surely help convince the doubters.

A chair by designer Poul Kjærholm uses walnut-coloured leather from Sørensen in this reproduction for Fritz Hansen.
Credit: Jonas Bjerre-Poulsen

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