Agence France-Presse: The world’s tallest building went dark, the Eiffel Tower lost its glow and lights were shut off at other sites across the globe Saturday in a campaign to boost the fight against climate change. Ferry horns blared across Sydney harbour in a noisy start to the Earth Hour energy-saving event, involving 4,000 cities in a record 125 countries. It was to include 1,200 landmarks from the Forbidden City to Egypt’s pyramids and the Las Vegas Strip, with iconic sites going dark for 60 …