Agence France-Presse: Tens of thousands of people across Europe demonstrated for action on climate change on Saturday, two days before world leaders gather in Copenhagen for landmark talks on tackling global warming. Protesters in London, Brussels, Paris, Stockholm and Dublin took to the streets to call for a far-reaching international agreement on reducing greenhouse gas emissions at the UN-led talks starting on Monday. As about 20,000 people marched through central London, British Prime Minister …