London Design Biennale: Here's why a forest has suddenly sprung up in the heart of London

Tap above to watch video report by Sally Williams

Nestled among the high rise buildings and busy streets of central London and unusual sight has sprung up. 400 trees have formed a mini forest to help bring an important message to the capital about climate change. It's part of the London Design Biennale at Somerset House - a global gathering of the world’s most imaginative designers representing a range of issues, brought together under the watchful eye of 'Love Actually' Director Richard Curtis.