It was the biggest of its kind in history.<br/> <br />Hundreds of thousands of people in cities around the world marched to bring attention to the issue of climate change on Sunday.<br/> <br />In New York, some 310,000 people walked through the streets of Manhattan holding signs and chanting slogans... (together united...)<br/> <br />In London, celebrities like actress Emma Thomson and musician Peter Gabriel joined the march.<br/> <br />Gabriel said climate change is a real problem and can't be ignored any longer.<br/> <br />(SOUNDBITE) (English) PETER GABRIEL, MUSICIAN, SAYING:<br/> <br />"I am now certain that this is a very real threat to our own survival and that we are blindly ignoring it at our peril."<br/> <br />From Melbourne to Paris, in more than 160 cities protesters said their aim is a world run entirely on clean energy.<br/> <br />Some 120 leaders plan to meet Tuesday at the United Nations in New York for a summit on climate change.<br/> <br />It includes talks on ways to lower greenhouse gas emissions in 200 countri
