With the launch of Gucci Equilibrium – an online platform "designed to connect people, planet and purpose" – in the same week as both World Environment Day and World Oceans Day, the brand picked the perfect moment to start a fresh conversation about the impact of the clothing industry. Cynics might call out such efforts – but consider this: according to the 2015 Nielsen Global Corporate Sustainability Report, 73 percent of millennials would pay more for sustainable products. There is clearly a business argument for taking the pressure off our planet – and that means there may be real substance behind Gucci's plan.

Read more: Gucci Furthers Its Commitment To Sustainability With Gucci Equilibrium

According to the 2018 Pulse of the Fashion Industry report, other brands are listening too: it revealed that 75 percent of fashion companies have improved their environmental and social performance over the past year. But with the demand for greener goods comes the demand for greater transparency. Much like the word "healthy" in relation to food, there are few trading standards that define what "sustainable" or "conscious fashion" actually mean. And until there are, greenwashing – the practice of making an unsubstantiated or misleading claim about the environmental benefits of a product, service, technology or company practice – is likely to be widespread across the industry and beyond. To gain a better understanding of what is being done to rectify the issue, Vogue interviews key players working to reduce the environmental impact of the fashion industry.

Read more: The Young Designers Pioneering A Sustainable Fashion Revolution

What are the world's biggest luxury brands doing to reduce their environmental impact?

Marie-Claire Daveu, chief sustainability officer at Kering:

"The classical evaluation system for measuring the sustainability of a company simply isn't accurate if it doesn't look beyond its own operations. So we developed a pioneering tool back in 2011 known as the Environmental Profit & Loss, to help us better understand our environmental impact in order to reduce it. Thanks to this, we discovered that only 7 percent of the impacts came from directly within the company (stores and offices) – but a staggering 93 percent of the issues were directly linked to our supply chain, for example cotton and cattle farming. This means if we really want to improve our business model, we need to trace our supply chain right back to the raw materials. For example, many of our brands – from Bottega Veneta to Saint Laurent – work with leather, so we developed a metal-free tanning process which is more environmentally friendly as it reduces pollution as well as water and energy consumption. If our aim is to protect the planet and we only look within our own operations, we aren't doing our job – the whole supply chain has to be taken into account."

So what can we do as consumers?

Amy Powney, creative director of Mother of Pearl:

"Sustainability is such a broad word and it's confusing for customers to navigate what it actually means when there aren't any trading standards around it. For example, just because a T-shirt is made from organic cotton doesn't mean it wasn't made in a sweatshop. It might be an exciting idea to make trainers using recycled plastic from the ocean, but what happens when those trainers end up in a landfill site? We, as designers, have to think of sustainability holistically, and always ask what happens to a garment after we've made it. As for consumers, the best way to be a more sustainable shopper is to buy less cheap and more quality. You should also decide what sustainability means to you: is fair trade most important, or tackling climate change? It's unlikely that you are going to find a brand right now that tackles everything."

Read more: 5 Changes To Make This Fashion Revolution Week

How can we better define what "sustainability" actually means?

Jason Kibbey, CEO of Sustainable Apparel Coalition:

"In 2009, the outdoor apparel company Patagonia and Walmart came together because they believed that more transparency was needed in the fashion industry. They wrote a joint letter inviting CEOs of leading global companies to come together to develop an index – now known as the Higg Index – that would measure the environmental impact of their products. Now we have over 200 global members – from Adidas and Asos to Levi's and LVMH. Our goal is to collect all this information and standardise it – similar to the food industry. Then you can share it so that consumers really understand how sustainable a garment is. This kind of standardised metric is going to be absolutely critical to preventing greenwashing."

Read more: Is The Growth Of Resale Really Linked To Sustainability?

Any final tips on how we can make our wardrobes more sustainable in the meantime?

Ryan Gellert, EMEA general manager of Patagonia:

"One of the best things we can do as customers is keep the product that we buy for longer, buy things of quality and repair something instead of disposing of it. When it comes to how you shop, make sure you do the research, ask probing questions and demand more from the brands that you do business with. We are repeatedly held up as an example of a sustainable company. We're not a sustainable company – we take more from the planet than the planet can restore. But we are a responsible company, in that we challenge ourselves to minimise our impact on the planet, and use our business to inspire and implement solutions to the environmental crisis. As an industry, we need to find ways to regulate ourselves, not because customers require more from us, not out of fear that governments will try and regulate us, but because it's the right thing to do."

Blue Heart, a feature-length documentary by Patagonia about the fight to save Europe's last wild rivers, is in cinemas now.