America's Environmental Protection Agency has announced that greenhouse gases are a danger to human health.

The ruling will allow it to regulate emissions without the approval of the US Congress - a move designed to show President Obama is taking climate change seriously.

Around 15,000 delegates are attending the talks which aim to agree immediate action to curb greenhouse gases and come up with billions of pounds in aid and technology to help poorer countries limit emissions...

The EPA would be able to order better insulation or greener technology to reduce emissions in the US, the world's largest economy and second biggest source of carbon blamed for global warming.