The design world’s focus on sustainability hasn't faded, despite the current hype surrounding the festive season.

In Australia, Sydney Harbour Foreshore Authority has designed and installed Sydney's most unique Christmas tree on George Street, The Rocks — and it’s made entirely from recycled plastic bottles.

The eight metre tall tree and five chandeliers in Kendall Lane have been created using 18,000 unusable plastic bottles of different sizes and colours. Each bottle has been sculpted and moulded by hand and a team of eight people spent more than 650 hours creating and installing the tree and chandeliers.

The tree acts as a visual gateway for visitors to The Rocks and is part of the Authority's focus on making its activities and events sustainable.

And it isn’t surprising that Copenhagen has incorporated sustainability into its Christmas celebrations. Every year a large Christmas tree lights up Copenhagen’s City Hall Square, but this year, if tourists and passers-by want to enjoy the tree in all its glory, they must work for it.

Throughout the Climate Summit, those concerned about the environment have been able to jump on a bike and use pedal-power to light up the tree. This will save the environment a total of nine tonnes of CO2 compared to the traditional way of powering the lights.

In London, Sarah Wigglesworth Architects was commissioned by developers, igloo, to design a unique Christmas tree for Bermondsey Square. The tree typifies sustainability by comprising 35 recycled bicycle wheels. The wheels come from a charity called Re-Cycle, which collects redundant bike parts, creates new bicycles and sends them to Africa for local people and health workers to use.