The global fashion industry, worth an estimated $2.7 trillion annually, is failing to act on its most urgent decarbonisation opportunity — replacing fossil-fuelled heat in production with clean alternatives — according to a new report.
The report, What Fuels Fashion? 2025 Edition published by Fashion Revolution, which ranked 200 of the world’s largest fashion brands, on September 30 warned that while technologies like electric boilers and heat pumps could slash emissions and improve factory conditions today, only six per cent of brands disclose efforts to electrify high-heat processes. Even fewer — 10 per cent — have renewable energy targets for their supply chains, where most emissions occur.
“Fashion’s climate future will be decided by how the industry tackles heat,” the report stated. “The technologies needed to replace fossil fuels already exist. What’s missing is the will and financing to scale them.”
The report highlights that overproduction and fossil fuel dependence converge in Tier 2 processing facilities — dye houses, laundries, and finishing mills — which are the single largest sources of supply chain emissions. These sites not only burn vast amounts of coal and gas but also expose workers to dangerous heat stress and polluted air.
“Electrification is not just a climate solution; it can also contribute to safer working environments and cleaner air for surrounding communities,” said Jan Rosenow, Professor of Energy & Climate Policy at Oxford University, in his foreword to the report.
Yet not a single brand discloses data on factory heat and humidity levels, leaving garment workers vulnerable as climate change drives up temperatures. Cornell University research cited in the report shows workers in Karachi and Phnom Penh already face around 115 unsafe heat days annually.
Despite rising climate risks, the report finds that 60 per cent of brands disclose energy sourcing for their own operations, but only 11 per cent do so for supply chains — where the bulk of emissions lie. Many rely on Renewable Energy Credits (RECs), which mask continued fossil fuel use.
“This is accounting, not accountability,” the authors argued, calling for brands to move to 24/7 renewable electricity matching instead of paper-based fixes.
Even basic supply chain transparency is stalling: just 35 per cent disclose processing facilities, a plateau after nearly a decade of pressure. Without visibility of where production occurs, mapping emissions hotspots or investing in clean heat remains impossible.
“Transparency is not a radical demand — it is the bare minimum,” said Liv Simpliciano, one of the lead authors and Fashion Revolution’s head of policy & research. “Without it, credible decarbonisation cannot happen.”
Jan Rosenow, professor of energy and climate policy at Oxford University, added: “The textiles industry can lead by example: because process heat rarely exceeds 250°C, it has the potential to move entirely away from fossil fuels. The possibility is here — now companies must commit and set clear strategies to enable the transition.”
Perhaps most damning is the finding that only six per cent of brands disclose any support for supplier capital investments to replace coal boilers, and just two per cent provide help with ongoing costs such as renewable energy bills.
“This creates a chicken-and-egg problem,” the report noted. “Suppliers cannot electrify if grids remain fossil-fuel heavy, while governments hesitate to invest in renewables without clear industrial demand. Brands sit at the centre of this deadlock.”
Among the 200 brands assessed, H&M, Puma, and Calzedonia Group emerged as top scorers, while Gucci, Lululemon, and Fashion Nova languished near the bottom with negligible disclosure.
Publicly listed companies, despite being answerable to investors, made up 59 per cent of those scoring zero on traceability, revealing what the report calls “a glaring accountability gap in ESG oversight.”
The report urges brands to electrify all thermal processes, invest in renewable grids, and adopt a Just Transition framework to ensure workers are not left behind. It also calls on investors and citizens to demand heat monitoring and brand accountability.
“Business as usual is over,” said Ciara Barry, co-author of the report. “If fashion fails to seize the clean heat opportunity now, it risks losing credibility in a world moving beyond fossil fuels — and compromising the health, safety, and dignity of the people who make our clothes.”