World leaders gather for 'crucial' UN climate meeting

Available for over a year

Will it herald new action on greenhouse gasses - or will it be just a lot of hot air? We'll hear how climate change could threaten our food supply in the years ahead. Also in the programme, trees for cash. Norway pays Liberia to stop deforestation. And as the White House reveals a plan to crack down on corporate tax avoidance, we ask whether it will it work. Plus the moment a Cambodian garment worker came face to face with something she had made, being sold on London's Oxford Street.