AAP: A wave of global climate change demonstrations has kicked off in Melbourne and the message from the crowd of about 30,000 is clear - it's time for action. The flagship People's Climate March is among the first of more than 2,500 which will take place around the globe in the next 14 hours, ahead of a UN summit on climate change in New York next week. No end in sight at the Melbourne March #PeoplesClimate pic.twitter.com/GOQAmRDl1g - 350 dot org (@350) September 21, 2014 World leaders will meet...