Australian-born Danish Queen Mary has called for the fashion sector to become an industry ''that gives more than it takes''.
The 52-year-old, promoted to Queen in January, delivered an opening address to the Global Fashion Summit in Copenhagen on Wednesday.
The style icon has long been a champion of sustainable fashion and climate change action and travelled to cyclone-prone Fiji and Vanuatu in 2023 to meet Pacific islanders on the frontline of global warming.
The annual two-day summit in Copenhagen discusses the fashion industry's environmental footprint, ethics, human rights issues and labour conditions in the supply chain.
''Our planet is beautiful and fragile and we have a responsibility to protect and preserve it for our children and coming generations,'' Queen Mary told the summit.
''Let's all imagine ... a fashion industry that gives more than it takes from people and planet.''
Queen Mary met her husband Frederik at a Sydney pub during the 2000 Olympics.
The couple celebrated their 20th wedding anniversary on May 14 and were pictured wearing matching vests aboard the royal yacht headed to Norway for an official visit.
The Danish Queen regularly re-uses outfits and ball gowns.
At this year's Danish royal New Year's Gala, she wore a burgundy gown that she had previously worn to six other official events.
The mother-of-four said her two daughters could fit into her clothes and shoes.
''But the age gap means they wouldn't be caught dead in them,'' she said.
''However, when they will be seen in something that is mine, it always brings a smile to my face.''
She hailed the trend of borrowing, swapping clothes and frequenting vintage stores and flea markets.
''New clothing is no longer seen in opposition to used clothing,'' she said.
Queen Mary said she looked forward to learning about planet-positive projects at the summit including ''the wonders of seaweed as an alternative to existing fabrics''.
In 2017, the Danish royal travelled to Bangladesh and visited a textile factory in Dhaka to learn about the plight of women garment workers.
In December, summit organiser Global Fashion Agenda announced a plan to team up with fashion brands BESTSELLER, H&M Group and Copenhagen Infrastructure Partners to develop Bangladesh's first offshore wind project.
The project, which aims to increase renewable energy availability in one of the fashion industry's key manufacturing countries, is in an early development stage with construction expected to start in late 2026.
The summit will also urge fashion movers and shakers to tackle animal exploitation.
On Thursday, Melbourne-based Collective Fashion Justice will urge a rethink on leather use.
"So often when we're talking about animal-derived materials we are too uncomfortable to acknowledge exactly what we are talking about ... animals being transformed through the supply chain into objects," founding director Emma Hakansson told AAP.
Ms Hakansson, 24, a former model, will appear in a photo exhibition posing in clothes made from alternative eco-friendly materials alongside animals that are typically exploited.
After lobbying, Melbourne Fashion Week banned feathers from its runways in 2024 in a world-first, London Fashion Week prohibited fur and Copenhagen Fashion Week outlawed feathers and skins from catwalks.
"It wasn't so long ago that Hermes made bags from whales and that London Fashion Week and London auction houses were full of hummingbirds that had been taken from the Amazon and turned into all kinds of jewellery," Ms Hakansson said.
