Designer Vivienne Westwood and Anvil Knitwear have joined forces to launch a limited edition T-shirt to support efforts at the UN Climate Change Conference in Copenhagen to stop deforestation.

Danish manufacturer Anvil provided eco-friendly T-shirts from its AnvilSustainable collection.

Each shirt is made with a blend of recycled polyester, derived from approximately three recycled plastic bottles, and transitional cotton that comes from farms that are converting to organic farming methods.

Eco-friendly printing for the shirts was provided by New Buffalo Shirt Factory.

"I am so glad to have had the opportunity to do this tiny, tiny thing - design a T-shirt - every little bit helps," said Westwood. "Act Fast/Slow Down and stop climate change. That's the message. We must all commit ourselves. Say Yes to the Rainforest."

A statement said that deforestation was responsible for approximately 20% of global greenhouse gas emissions, more than all the world's cars and trucks combined.

"Environmental issues are extremely important to Anvil - we manufacture in Central America, and rainforests are in our backyard," said Anthony Corsano, CEO of Anvil Knitwear.

"We try our best to walk the talk by improving energy efficiencies, reducing greenhouse gas emissions and using materials that are less harmful to the environment, and we are honoured Vivienne Westwood and the Coalition for Rainforest Nations selected us to partner with them on this important campaign."