Luxury fashion brands are going green. But why are they keeping it a secret?

Kering has started quantifying the environmental impact of its products. This chart estimates the amount of land and water used and the amount of carbon emissions required to produce the silk, wool and wood for one designer dress, and assigns a Euro value for each factor. (Kering/Courtesy of Kering from its 2014 Environmental Profit and Loss Report)

The Paris-based LVMH, which controls Louis Vuitton, Céline, Givenchy, Christian Dior and Fendi, among other luxury brands, began to focus on sustainable business practices in 1992 in its wine and spirits division. This fall, LVMH announced the creation of a carbon fund that each brand pays into based on its energy consumption. The approximately $5.3 million fund supports projects such as upgrades from traditional lighting to LED.

In June, Kering released its first Environmental Profit and Loss Report, examining where in its chain of more than 1,000 suppliers in 126 countries lurk the largest and gravest impacts on the environment. Looking at all its labels — from the silk T-shirts and motorcycle jackets of Saint Laurent to the sports gear of Puma — Kering measured water consumption, air pollution, greenhouse gas emissions and land use. It then translated these findings into euros to estimate how much the production of, say, a single leather handbag costs the environment: 11.85 euros last year, or about $12.53.

In 2013, Kering’s luxury goods cost the environment about $817 million. (A similar conglomerate, operating without environmental restraint, would have put a strain of $1.2 billion on the planet, according to PricewaterhouseCoopers.) In 2014, that environmental cost ticked upwards by 2.2 percent to $838 million — while revenue grew by 4.5 percent.

In this chart, Kering estimates the land and water usage and carbon emissions associated with producing the leather, brass and linen for one handbag. (Kering/Courtesy Kering, from the 2014 Environmental Profit and Loss Report)

Kering posted this data online so other manufacturers could learn from their lessons. “When you are speaking about sustainability, if you keep it all for you, you won’t change the paradigm,” says Marie-Claire Daveu, Kering’s chief sustainability officer.

The Kering report also revealed that only seven percent of the company’s environmental impact was at its boutiques, headquarters and warehouses. Fifty percent came from the production of raw materials. And 25 percent was from processing those materials. The most significant impact included the greenhouse gases from cattle ranching and the land and water dedicated to traditional sheep farming.

The goal is not to ban wool or leather but to find more environment-friendly ways to produce it. Kering and LVMH, for example, are moving away from traditional tanning methods that use chromium.

But bright candy colors typically cannot be produced without using heavy metals, says Sylvie Bénard, corporate environment director at LVMH. There’s also a concern with color stability. A customer can’t get caught in a rainstorm and find her handbag dripping dye onto her cashmere trousers. Gucci developed an organic tanning technique and in 2013, began using it to produce special-order, bamboo-handled bags. Louis Vuitton’s Gaia Monogram Cerise handbags now use vegetable-tanned leather.