Sustainable clothing is striving to clean up the apparel industry’s reputation as the second most polluting industry on the planet. Mango has a new, mostly organic cotton collection in stores this season. Zara’s collection spotlights, among other green fabrics, a closed-loop material called Refibra made of recycled Tencel and cotton scraps.

H&M has a pleated gown in a fabric called Bionic, a polyester made from recycled plastic shoreline waste. The Swedish clothing giant has a target of using exclusively sustainable fabrics by 2030.

The definition of sustainable can vary widely, depending on the brand, but it generally involves some combination of greener supply chains, sourcing eco and recycled fabrics, manufacturing locally or ethically offshore and minimizing waste, polluting chemicals and energy consumption.

So every brand has to find its own eco recipe, depending on its financial and material resources and values. Ethical fashion brands are going after a growing demographic of aspirationals, a mix of hopeful millennials and Gen-Xers, that like to shop but prefer supporting brands with integrity.

Brands are entrenching sustainability throughout the supply chain. They're building proper sustainability teams instead of just tacking on a sustainable marketing director and green washing.

Brands are starting to calculate what climate change will do to their bottom line while coming to terms with their businesses' cost to the planet.