China becomes the world leader in wind power
In China, more and more cities are seeing their streets filled with smog as cars and power stations pollute the air. One response by the Chinese government is to launch a major push for cleaner renewable energy. China is now the world's leading producer of wind power and it has plans to install thousands of turbines every year, especially in the remote regions in the country's far west.
That's where the BBC's science editor David Shukman is, and he sent us this report.
Listen to the full audio above.