A 16 foot high sculpture of an iceberg featuring a stranded polar bear and its cub was launched on the River Thames in London today to mark the launch of a new natural history TV channel.

A team of 15 artists spent two months constructing the 20′ x 20′, three thousand pound, 100% recyclable structure which was launched in Greenwich, South East London at 6:30 this morning. The sculpture traveled 7.5 miles up the Thames before stopping beside Tower Bridge and the Houses of Parliament for a photo op.

>>Watch video of the polar bears on the Thames

The sculpture was specially commissioned to mark the launch of the new Natural History Television channel Eden, which starts today and features programming including Planet Earth and Attenborough Explores Our Fragile World.

Speaking about the sculpture, Sir David Attenborough said: “The melting of the polar bears’ sea ice habitat is one of the most pressing environmental concerns of our time. I commend Eden for highlighting the issue; we need to do what we can to protect the world’s largest land carnivores from extinction.”

The Thames is no stranger to unexpected mammalian visitors. In January 2006 a seven-tonne bottle-nosed whale became trapped in shallow water near Battersea Bridge. Other mammals which have strayed into The Thames include a family of Harbour Porpoises, which were spotted near Vauxhall Bridge in December 2004.

Now that the polar bears’ have finished their inaugural journey along the Thames, they will be taking their message about global warming (and, of course, the new network) to Hampstead Heath as well as key cities across the UK including Birmingham and Glasgow.

Images courtesy of: www.exploreeden.co.uk