A sculpture of a polar bear and her cub stranded on an iceberg was floated down the Thames to raise awareness of climate change. The 16ft high structure was launched in Greenwich, south east London and travelled upstream to Tower Bridge past the Houses of Parliament and the London Eye.A team of 15 artists spent two months working on the sculpture to draw attention to the plight of the Arctic mammal and the impact of global warming on the icecaps. The work was commissioned by Eden, a new digital television channel devoted to natural history programming. Wildlife broadcaster Sir David Attenborough said: "The melting of the polar bears' sea ice habitat is one of the most pressing environmental concerns of our time. We need to do what we can to protect the world's largest land carnivores from extinction"
