The Town of Carrboro is encouraging residents to observe Earth Hour, starting at 8:30 p.m. this Saturday. An international observation aimed at underscoring the need to work together to fight climate change, those who want to observe Earth Hour are asked to turn their lights out for the hour. Last year, more than a billion people from 4,100 cities in 87 countries turned out their lights. International landmarks including the Golden Gate Bridge, Empire State Building, Eiffel Tower and Great Pyramids, and the city skylines of Las Vegas, Hong Kong and Tel Aviv, went dark as well.