AAP: FOUR Greenpeace activists protesting against coal-fired power have begun their descent from a 140-metre high smokestack where they have spent the past 24 hours. A Greenpeace spokesman said the three men and woman were confident opf getting across their message about the need for renewable energy during their vigil atop Swanbank Power Station, west of Brisbane. This morning two of the men abseiled down the side of the smokestack and painted “go solar”. Nine …