Winter Olympics: Will the Beijing Games be 'green and clean'?

China has promised to deliver a "green and clean" Winter Olympics, which gets under way on 4 February.

Organisers say they have prioritised protecting native species, reducing greenhouse gas emissions and cutting down on resources used.

But there's been criticism that this will be the first Winter Olympics to rely entirely on artificial snow - and that some events will be held in the middle of a nature reserve.

The Olympics will be hosted across three sites, and Yanqing will host the popular Alpine ski events.

But the ski runs have been constructed in the middle of the Songshan nature reserve in Yanqing - over an area bigger than a thousand football pitches.

The construction required removing more than 20,000 trees, which was done during the last few years.