The multitrillion-dollar business of fashion, with its complex and long supply chain, is worryingly vexed with problems contributing to climate change.

The fashion industry emits more greenhouse gas than all international flights and maritime shipping journeys combined , and it's estimated that a garbage truck's worth of clothing is either burned or sent to a landfill every second. On top of that, thanks to our powerful washing machines, our clothes pollute the ocean with microfibers equating to approximately 50 million plastic bottles each year.

Conversation and action around sustainability and climate change has been quiet and slow to come within the sector, but Monday marks another move toward collective change. A fashion industry charter for climate action was formally launched at this year's United Nations climate change conference, COP24, in Katowice, Poland.

Support for the new charter has come from high street retailers, luxury fashion houses and other suppliers within the sector. Stella McCartney, Burberry, Adidas and H&M Group are included in the list of 40 signatories.

Stella McCartney attends the Fashioned From Nature VIP preview at The V&A on April 18, 2018 in London. McCartney's eponymous label is a leading player in sustainable fashion. Credit: John Phillips/Getty Images Europe/Getty Images

Aligned with the goals of the Paris Agreement, the new charter includes 16 principles and targets. The companies involved have committed to reducing their aggregate greenhouse gas emissions by 30% by 2030 and they've agreed to prioritize low-carbon transportation suppliers and favor climate-friendly materials.

Stella McCartney, whose eponymous label is already a leading player in sustainable fashion, was one of the founding signatories. She announced her involvement in late November during Voices, a fashion industry conference staged in the English countryside, where she was also honored for her work in the sector.

Fashion's new vanguard

During an interview at the conference, she acknowledged the complexities of working sustainably and responsibly: "There are millions of limitations from a design and creative point of view. There are millions of limitations from a sourcing and manufacturing point of view. But for me, all of those challenges are part of being a designer and part of being a businesswoman."

McCartney called upon her peers in the industry to sign the charter, urging the industry to work together.

"It's a no-brainer but there has to be a collective conversation," she said. "I think that's what's so powerful and exciting and promising about COP24."

A model walks in Burberry during a show for the Spring/Summer 2019 collection at London Fashion Week on September 17, 2018. The fashion label said it would ban its practice of destroying unsold products. Credit: NIKLAS HALLE'N/AFP/AFP/Getty Images

Burberry was recently criticized when it was revealed the brand destroyed clothes and perfume worth more than $36 million in 2017. After widespread outrage, the luxury fashion label said in September that it would ban this practice