Fashion giants are under fresh pressure to curb their environmental impact following the launch of the UN Alliance for Sustainable Fashion today.

Hot on the heels of the UN Sustainable Fashion Charter, launched at a UN climate summit in Poland in December, the UN Alliance for Sustainable Fashion aims to work with sustainable fashion initiatives and UN agencies around the world to drive efforts to improve the performance of the fashion sector, one of the most environmentally damaging industries on the planet.

Fashion is the world's second-biggest consumer of water and one of the largest sources of marine pollution, generating around 20 per cent of the world's wastewater and releasing half a million tons of synthetic microfibres into the ocean every year.

Meanwhile, consumers are buying more clothes and keeping them for less time. Globally, the average consumer buys 60 per cent more pieces of clothing than 15 years ago, and keeps each item for only half as long.

UN agencies are already working to reduce fashion's impact. For example, the UN Food and Agriculture Organisation is promoting Blue Fashion, which uses sustainable marine materials and protects arable land; the International Trade Centre has set up the Ethical Fashion Initiative; and UN Environment is pushing governments to encourage sustainable manufacturing practices.

The UN said the new Alliance will scrutinise the efforts of these UN agencies, working to identify gaps in their activities and lobbying governments to take action to close them.

It will also work to leverage business sustainability efforts, helping the Ethical Fashion Initiative to convene annual forums with fashion giants such as Hugo Boss, Gap, and H&M.

"Research shows that fashion presents many opportunities for reducing waste and improving the environment," said Siim Kiisler, president of the UN Environment Assembly. "But the fashion industry cuts across many sectors, and so to capture the full opportunity, the UN and its partners need an integrated approach that goes beyond individual Sustainable Development Goals."

The group will run alongside the Fashion Industry Charter for Climate Action, which was formally unveiled in December with the backing of 43 fashion organisations, including consumer brands, key suppliers, and sustainable fashion organisations.

The Charter contains a series of promises designed to encourage the fashion sector to align with the goals of the Paris Agreement, including an ambition to deliver a pathway for net zero emissions by mid-century.

In related news, the Better Cotton Initiative (BCI) revealed this week that a record number of fashion brands sourced more sustainable cotton through its programme last year.

Some 93 retailers and brand members sourced more than one million metric tonnes of cotton through the BCI, which trains cotton farmers around the world in sustainable production practices.

Uptake rose 45 per cent in 2018 compared to a year earlier, the BCI said yesterday, with H&M sourcing the largest volume for the third year running. "Cotton is one of H&M group's most important materials - BCI plays a key role in our goal towards using only sustainably sourced cotton by 2020," said Mattias Bodin, Sustainability Business Expert, Materials and Innovation at H&M group.